ID 114 
ISSUED: 9-92

1. Introduction
(Lloyd Murdock, Jim Herbek and Steven K. Riggins)
Canola-quality rapeseed is one of the world's leading edible oil crops. Soybean oil (30%), palm oil (16.7%), rapeseed oil (13.9%) and sunflower seed oil (13.8%) collectively account for almost 75 percent of total world edible oil production. Leading producers of rapeseed (all types) are China, European Community (EC), Canada and India. World production of rapeseed has increased faster over the past two decades than that of any other oilseed. Over the last 15 years, rapeseed production has achieved an annual average growth rate of seven percent while soybean output grew annually at only four percent.
World trade in rapeseed and its products, oil and meal, has also achieved spectacular growth. Rapeseed exports are now the second largest volume oilseed traded following soybeans.
Canola is a specific type of rapeseed associated with high quality oil and meal. The name "canola" identifies the seed as having 2 percent or less of erucic acid in the oil and less than 30 micromoles per gram of glucosinolates in the oil-free meal. Rapeseed not meeting these standards cannot be termed canola.
Canola oil is lower in saturated fats (6%) than any other vegetable oil. Other edible oils and their saturated fat contents are: Safflower -- 9 percent; Sunflower -- 11 percent; Corn -- 13 percent; Olive -- 14 percent; Soybean -- 15 percent; Peanut -- 18 percent; Cottonseed -- 27 percent; Lard -- 41 percent; Palm -- 51 percent; Butterfat -- 66 percent; and Coconut Oil -- 92 percent.
Canola seeds contain about 40 percent oil by weight and the oil is used as a salad and cooking oil and in other processed foods. The meal is about 37 percent protein after oil extraction and is a high protein livestock and poultry feed.
Rapeseed is grown in the cooler areas of the world's agricultural regions such as North America, Northern Europe, China and India. The oil has been used for centuries in Europe and Asia as both a cooking and lamp oil and later as a lubricant and fuel. But only recently were canola cultivars developed that reduce erucic acid and glucosinolate levels in the oil and meal, respectively. This development made rapeseed safe for human and animal consumption. Canada was the leader in this effort. Since that time, consumption of canola oil has increased at a rate greater than that of any other edible oil. It is a major edible oil in China, India, Japan, Canada and many European countries. Japan is the only country in this group that is not a major canola producer.
In 1985, the U.S. Food and Drug Administration (FDA) granted GRAS (Generally Recognized as Safe) status to canola oil. Since that time, domestic consumption has steadily grown.
Yet, production in the United States is currently only about 10 percent of domestic demand. The driving force behind increased demand is the health-conscious consumer. Because the oil contains less than half the saturated fat of any other vegetable oil, has a favorable mix of mono- and polyunsaturated fats, and, like other vegetable oils, contains no cholesterol, the food industry is realizing canola's benefits. All major food processors in the United States are evaluating or using canola oil in their line of cooking oils and in an increasing number of processed foods.
Kentucky seems well positioned to take advantage of this opportunity.
The crop is well adapted to the climate. Yields of 70 to 90 bushels per acre have been obtained in research trials. Yields from production fields have ranged from 20 to 60 bushels per acre with an average of 35 to 40 bushels per acre.
Canola fits well into our cropping systems because it can be double-cropped with soybeans.
Production practices, equipment needs, production costs and the growing season for canola are quite similar to wheat.
Canola offers a profitable opportunity to diversify crops and break disease and pest cycles established by using present crops.
Government feed-grain and wheat program provisions have been modified to allow more flexibility in planting decisions by farmers. Some of these provisions, such as the ability to plant canola and other non-program crops on program crop base acreages, allowance of double-cropped soybeans after canola on 0-92 land, and a marketing loan rate that is favorable relative to the target price for wheat, encourage canola production.

The acreage harvested in the state was estimated at 1,000, 8,000, 20,000, 7,000, and 9,000 in 1987, 1988, 1989, 1990 and 1991, respectively.
Management decisions will make or break any adopted crop. Canola will not be a success in Kentucky without increased knowledge of canola management and an improved marketing system.

2. Plant and Growth Characteristics
(Jim Herbek and Lloyd Murdock)
What is Canola?
Plant Classification
Canola, an oilseed crop, is a genetically altered and improved version of rapeseed. Rapeseeds as a whole are cool-season annuals of the Cruciferae (mustard) family belonging to the genus Brassica. The mustard family consists of about 3,000 species of plants mainly found in the Northern Hemisphere. The name "crucifer" originated from the four petals of the flowers arranged diagonally opposite each other in the form of a cross. The Brassica genus contains many species of domesticated crops grown for their oil, seeds, food (roots, stems, leaves, buds and flowers) or forage. Even within a single species, crops have been developed for different purposes. Being a member of the Brassica genus, rapeseed/canola is closely related to mustards and vegetable crops such as cabbage, turnip, kale, collards, cauliflower and broccoli. The word "rape" in rapeseed actually comes from the Latin word "rapum" which means turnip. Some related weed species included in the Cruciferae family are wild mustard, stinkweed, shepherd's purse and common peppergrass.
Canola-quality varieties are presently developed from either of two species of oilseed rape: Brassica napus (also called Argentine rape, summer rape, winter rape or Swede rape) and Brassica campestris (also called Polish rape, summer turnip rape and field mustard). Traditionally, farmers have grown canola varieties from these two species. However, Canadian plant breeders recently have managed to cross the mustard plant (Brassica juncea) with canola to produce a canola-quality Brassica juncea that has some advantages over the traditional canola varieties. Some of these varieties may be available in five to 10 years.
Canola varieties currently grown in Kentucky were developed from the B. napus species which is more suitable for winter rapeseed production in the United States. This species has a higher yield potential, better quality and later maturity than B. campestris. It is largely self-pollinating, relatively tall (50 to 55 inch height), slightly more uniform in flowering and more prone to shattering when ripe. Seeds are generally larger and brown to brownish black when mature. Buds are at a higher level than recently opened flowers and upper leaves encircle only half of the stalk.
B. campestris fits into the short summer growth periods in Canada. This species is lower yielding, largely cross-pollinated, earlier maturing than B. napus (10 to 14 days), shorter (about 40 to 45 inch height), less even in maturity and more resistant to shattering. Its seeds are slightly smaller and yellowish brown to brown when mature. The buds are at a lower level than recently opened flowers and the lower part of leaf blades grasp the stalk completely.

History of Rapeseed/Canola
History suggests that rapeseed has been cultivated for several thousand years with its origins in Asia. Rapeseed was one of the few oil sources that could be successfully grown in the cooler (temperate) areas of the world's agricultural regions. Rapeseed was grown in Europe as early as the 13th century. In later centuries, it was used as both a cooking and lighting oil. Rapeseed had limited industrial use until the development of steam power, when it was discovered that the oil was an excellent lubricant for steam engines. It was in the 1940s that Canadian rapeseed production increased in response to a demand for the oil as a lubricant. However, in the 1950s demand dropped with a change to diesel power and to expanded use of petroleum products.
Edible vegetable oils are made up of components called fatty acids which determine the use of vegetable oils for edible or industrial uses. Some of these fatty acids are considered essential in human diets while others are not. Brassica (rapeseed) oils characteristically have a large amount of a long-chain fatty acid called erucic acid. Prior to the 1960s, the erucic acid content of rapeseed oil was not of particular concern when evaluating the oil's use for edible purposes. During the 1960s, however, a considerable body of research began to indicate that there could be negative health effects, particularly heart abnormalities, associated with the consumption of erucic acid in rapeseed oil. Because of the high levels of erucic acid in oil from traditional rapeseed varieties, the oil was not considered safe for human consumption. Concern about erucic acid prompted Canadian plant breeders to look for new genetic sources with low erucic acid levels. This resulted in the development of new varieties in the late 1960s and early 1970s with a low erucic acid content. This represented a major quality improvement in the oil and provided the opportunity for rapeseed oil to be used in food products for human consumption.
While rapeseed oil quality was being improved, Canadian plant breeders were also working to improve the quality of the protein meal co-product. While rapeseed meal was an excellent source of protein with a favorable balance of amino acids, its use was limited by its high glucosinolate content. Most plants of the mustard family contain glucosinolates (sulfur compounds). These compounds are responsible for the flavor, odor and taste of mustards, radishes, turnips and other cole crops. Traditional rapeseed varieties contained high levels of glucosinolates in the meal which caused palatability, nutritional (depressed growth, lower feed efficiency) and thyroid problems when fed in sufficient quantities to livestock. The effect is more prominent in non-ruminant (swine and poultry) than in ruminant animals. Canadian plant breeders initiated a search for genetic material low in glucosinolates which was then utilized to successfully reduce the levels low enough in varieties by the mid-1970s for the meal to be used for livestock feed.
In 1978, the rapeseed industry in Canada adopted the name "canola" to identify these new rapeseed varieties which are genetically low in both erucic acid and glucosinolates and to distinguish them from ordinary rapeseed. The name "canola" is an international registered trademark of the Canola Council of Canada.
Rapeseed is not a new crop to the United States. During the first half of this century, rapeseed (commonly called rape) was primarily grown as an annual forage for all types of livestock. Since then very little rapeseed, except for some industrial rape, had been grown. Prior to 1985, the Food and Drug Administration (FDA) had banned the sale of rapeseed oil for human consumption in the United States, primarily because it was considered unsafe. This ban was imposed in the 1940s to reduce possibilities of contamination of edible oils with the more toxic industrial rapeseed oils. However, in 1985, largely as a result of the development of the canola-type edible oils, the FDA gave GRAS (Generally Regarded as Safe) status to rapeseed oil low in erucic acid for use in U.S. food products. This opened the door for the United States not only as a major potential market for the edible oil, but also as a producer of canola to meet the demands of the edible oil market.

Canola Qualities and Terminology
There is often confusion about canola and the terminology used to describe it. The term "canola" refers to a quality standard; not a biological classification. Canola describes those varieties of rapeseed which produce both a superior quality edible oil and a high value animal feed.
In order to be considered as canola or as being of canola quality, the standard requirements are an oil which contains less than two percent of the total fatty acids as erucic acid and a meal which contains no more than 30 micromoles of glucosinolates per gram of air dry, oil free meal. Rapeseed not meeting these standards cannot be termed canola and is considered unsafe for human or animal consumption.
Canola varieties having both low erucic acid (<<2%) and glucosinolates (<<30 micromoles per gram) are also referred to as double-low or double-zero (00) rapeseed. Canola is also sometimes referred to as LEAR (low erucic acid rapeseed) because of its low erucic acid content.
Canola oil's superior properties are found to be very desirable as a liquid salad and cooking oil. It has also been found suitable for use in shortenings and shortening oils as well as margarines and margarine oils. The food industry is utilizing the oil in an increasing number of food products.
There are public concerns about the effects of saturated fats on blood serum cholesterol level, heart disease and human health. Substituting unsaturated fat for saturated fat or reducing intake of saturated fat is believed to reduce cholesterol levels and health risks. No vegetable oil, including canola, contains cholesterol. However, vegetable oils do vary greatly in the percentage of saturated fats they contain. Canola oil has a lower level of saturated fats (only 6%) than any other edible vegetable oil and also has a high proportion of unsaturated fat containing a favorable mix of both mono- and polyunsaturated fats.

Other Rapeseed
There is another edible rapeseed of low erucic acid content that is not of canola quality because it has a high glucosinolate content. These varieties are referred to as single-low or single-zero (0) rapeseed. Because of its low erucic acid content, single-low rapeseed can also be referred to as LEAR. Most European rape was single-low rapeseed which still had relatively high levels of glucosinolates, however, they are now moving to varieties of double-low (canola) quality.
Industrial rapeseed values a high erucic acid content which is in contrast to edible rapeseed oil. This rapeseed type is often referred to as HEAR (high erucic acid rapeseed). Traditional rapeseed varieties contained 20 to 40 percent erucic acid in their oil. Newer, improved varieties of HEAR now range from 40 to almost 60 percent erucic acid content. A minimum acceptable erucic acid content of 40 percent is required for industrial use. Industrial rapeseed is used as a lubricant; an additive in the production of cosmetics and toiletries, lacquers, detergents, pharmaceuticals, plastic formulations and nylon manufacture; and as a raw material in the chemical industry.
Although industrial rapeseed may contain any level of glucosinolates, the meal usually has a fairly high content making it unsuitable for animal consumption. Breeding improvements have led to lower glucosinolate levels, resulting in greater economic value to the meal.
Table 2-A lists the oil and meal characteristics of the various types of rapeseed which have been discussed.

Table 2-A. -- Oil and Meal Characteristics of Types of Rapeseed.
Type Other names Oil
(% erucic acid)
Glucosinolate content of
meal (micromoles/gram)
Canola or "00" double-low
less than 2 less than 30
"0" single-low
less than 2 greater than 30
Industrial HEAR greater than 40 usually >30 but 
can be <<30

Plant Characteristics
Canola is an annual. It is grown as a spring crop (spring-seeded) in Canada and the areas in the Northern United States that suffer severe winters. In more southerly latitudes, such as Kentucky, canola can be grown as a winter crop (fall-seeded). Winter canola usually out yields spring canola. When plants emerge in the fall, the seedlings and early growth resemble cabbage, turnip or mustard greens. Plants go dormant during the winter and much of the leaf tissue freezes.

The plant bolts rapidly in the spring sending up a single flowering stalk. Canola grows to a height of four to five feet. The portion of the stalk containing the pods will eventually be 10 to 15 inches long.
Canola flowers are bright yellow and a field in full bloom is quite showy. The yellow flowers are characteristically four-petaled in the form of a cross. The rapeseed plant produces more flowers than it has capacity to set pods.
Following pollination, an elongated pod is formed with two chambers separated by a membrane with a single row of seeds within each chamber. The green (tan when mature) pods will be about 1/2- to 3-inches long, 1/8-inch wide and contain 15 to 30 small, round seeds depending on species, variety and environment. Seeds are mature 12 to 15 weeks after spring regrowth.
The seeds of the B. napus species are brown to black when mature. There are about 115,000 seeds per pound. Seeds are about 1/32- to 3/32-inch in diameter but seed size varies with variety and environmental effects.
Standards for canola are a test weight of 50 pounds per bushel and a moisture content of 10 percent. Upon extraction, canola seed yields about 40 percent oil by weight (versus 20% for soybeans) making it one of the most efficient oil producing crops available. After extraction, the residual meal contains 36 to 38 percent protein.

Growth Stages of Winter Canola
A grower who has an understanding of how a canola plant grows can make more effective management decisions. The growth of a canola plant can be divided into some recognizable growth stages. The length of each growth stage is influenced by temperature, moisture, light, nutrition, variety and environment.

Pre-Emergence (Germination)
Seed has been planted but prior to plant emergence. The seed absorbs water and the root emerges growing downward. The stem (hypocotyl) begins growing, pushing two leaf-like cotyledons (seed leaves) up through the soil.

The plant has emerged four to 10 days after seeding. The two leaf-like cotyledons at the top of the stem have unfolded and expanded. The root continues development downward. The growing point of canola is above the soil between the two cotyledons. The exposed growing tip makes canola seedlings susceptible to any hazard which results in destruction of the seedling below the cotyledons.

Seedling develops its first true leaves within a week after emergence. The plant grows rapidly forming a dense canopy of leaves. It quickly establishes a rosette with older leaves at the base increasing in size and smaller, younger leaves developing in the center. Stem length remains essentially unchanged although its thickness increases. The root system continues to develop with secondary roots growing outward and downward from the tap root. A plant can have from two to eight or more leaves developed prior to winter dormancy depending on planting date and other management factors. A rosette in at least the six to eight leaf stage (six to 10 inches in height) is preferred.

Winter Dormancy
Growth slows and plants become dormant as temperature drops and daylength shortens in late fall and early winter. Leaves discolor (often showing purple discoloration) and die off. Much of the leaf tissue freezes during the winter. As long as the crown does not die, the plants are alive.

Spring Regrowth
Growth resumes in late winter and early spring as temperature increases. New leaves develop near the soil surface from the plant crown.

Budding and Bolting
Daylength and temperature trigger floral initiation. A cluster of flower buds becomes visible at the center of the rosette and rises as the stem rapidly bolts or lengthens. Leaves attached to the stem unfold as the stem lengthens. Secondary branches arise from axils of upper leaves of the main stem and also develop flower buds. Bolting usually lasts one to two weeks.
The main stem reaches 30 to 60 percent of its maximum length just prior to flowering. Rapid development and growth of a large leaf area strongly influence pod set and early seed growth on the main stem and first few secondary branches. Leaves at the start of flowering, especially the upper ones, are the major source of food for growth of stems and buds and their removal results in a large seed yield loss.

Flowering begins with the opening of the lowest bud(s) on the main stem. Flowering continues upward with three to five or more flowers opening per day. Flowering at the base of the first secondary branch usually begins two to three days after initial flowering on the main stem. During flowering, the plant continues to grow and to develop new buds. Full plant height is reached by peak flowering. Flowering normally lasts about three weeks but varies depending on weather conditions.
Flowers remain receptive to pollen for up to three days after opening. Fertilization occurs within 24 hours of pollination. After pollination and fertilization, the flower petals wilt and drop two to three days after the flower opened. A young pod becomes visible in the center of the flower a day after petals drop. Seed pods develop from the bottom of the flower cluster and proceed upward since the first buds to open on main stems and branches are the lowest buds. During flowering, pods, flowers, and buds occur simultaneously on plants with pods on the lowest part of stems and branches; open flowers above them; and above the flowers, buds which are yet to open. All of the buds that will develop into open flowers on the main stem will likely be visible in B. napus within three days after the start of flowering. By mid-flower, lower pods have started to elongate. By the time flowering is complete, lower pods have started to fill with the seed enlarging.
Canola plants initiate more buds than they can develop into productive pods. The flowers open, but the young pods fail to enlarge and elongate and eventually fall from the plant. This abortion of pods is a natural occurrence. Studies have shown that only 40 to 55 percent of the flowers produced on a plant develop productive pods which are retained until harvest. If unfavorable growing conditions or damage at early flower cause abortion or loss of flowers or pods, the plant can recover by the development of those buds which otherwise would have been aborted.
By mid-flower when lower pods have started elongating, the stem has become the major source of food for plant growth with a reduced amount from the declining leaves and a small amount from the developing pods. The earliest developed pods have a competitive advantage over the latest formed ones for the food supply. Any stress resulting in a decrease in food supply during pod development results in fewer flowers and fewer pods retained to maturity. Pods will also be smaller with fewer and lighter seeds, especially in later branches and tops of branches.

The ripening stage begins with the petal falling from the last formed flower on the main stem. Canola ripens from the bottom of the main stem and branches and continues upward. Thus, pods at the bottom may reach maturity while pods at the top of the plant are still developing. At the beginning of this stage, flowering may still be continuing on some of the later, secondary branches.
During seed development, seeds attain full size quickly. At full size, the seed initially is somewhat translucent (resembling a water-filled balloon). At this time, the seed's embryo begins rapid development within the seedcoat, filling the space occupied by fluid. This results in a firm, green seed and an increase in seed weight. About 35 to 45 days after a flower has opened, seed filling is complete.
Seed filling is followed by a maturing or ripening stage characterized by plant color changes. By the time flowering has finished, most leaves, pods and stems have turned yellow. Seeds, contained in two rows in the pod divided by a membrane, complete filling (physiological maturity) at about 40 percent moisture and then slowly change color from green to brown to black. Seed moisture is rapidly lost at one to three percent or more per day, depending on environmental conditions. At 40 to 60 days after first flower, the seeds in the lower pods have ripened and fully changed color. When 30 to 40 percent of the seeds on a plant have begun to show seed color change to brown or black, the average seed moisture is 30 to 35 percent. When all the seeds in all pods have changed color, the plant dies.

Environmental Effects on Growth
Moisture at Seeding
Moisture is one of the major factors controlling germination. Canola seed requires a high percentage of its weight in water before germination begins. The soil moisture levels required for winter canola germination and emergence are higher than either wheat or barley. A loose or dry seedbed often results in slow or uneven germination and may inhibit germination altogether until a rain occurs. Soil moisture must be conserved during seedbed preparation. A firm seedbed reduces the loss of moisture at the surface. Coarse textured soils dry more rapidly than finer texture soils.

Water Requirements for Plant Growth
Water, either too much or too little, can limit yield potential. Canola plants require large amounts of water. The crop uses an estimated 18 to 22 inches of water to produce good yields. Water use varies from 0.1 inch per day at the rosette stage to a peak of 0.3 inch per day during flowering. Heat and wind increase water use.
Moisture stress during the early vegetative stages reduces leaf expansion and root growth. Moisture stress during flowering and ripening results in large yield decreases from wilted leaves and reduced branching, pods per plant, pod length, seed size and seeds per pod. The flowering period and maturity are also shortened, especially when combined with high temperatures. Research has shown that the response to irrigation is greatest if water was maintained during flowering and pod-filling.
Canola requires a good mix of water and air in the soil and will not tolerate excessive amounts of moisture. Poorly aerated soils restrict root growth and affect water and nutrient uptake. Canola can tolerate only brief periods of flooding or ponding.

Temperature Effects
Overall Effects on Growth
Canola has a reasonably wide adaptability to perform well in many areas under variable temperatures. Canola prefers relatively cool temperatures up to flowering. The minimum temperature for canola growth is 41oF. This temperature is accepted as the threshold below which little significant plant growth occurs. Since canola is a relatively cool season crop, its best growth occurs above 54oF and below 86oF. The optimum temperature for maximum growth and development has been estimated at just over 68oF. Temperature effects vary with stage of growth.
Germination, emergence and early leaf development are influenced by soil temperatures. Soil temperatures above 50oF result in a higher germination percentage, quicker emergence and rapid leaf development. Because canola in Kentucky is planted in early fall, low soil temperatures should not be a problem for germination and emergence. Heat injury to seedlings can occur if air temperatures approach 90oF with soil temperatures above 100oF. Although heat injury is associated with drought injury, excessive heat injures plants even if soil moisture is plentiful.
Winter rapeseed must have several weeks of temperatures near freezing with a minimum of two to four leaves for it to undergo vernalization or it will not enter the flowering and reproductive stages. At flowering, warm temperatures are preferred with soil moisture readily available. Cool but non-freezing temperatures just prior to or at flowering slow the rate of plant development, delay flowering, slow flower opening and reduce pollen shed. High temperatures at flowering hasten the plant's development, reducing the time from flowering to maturity. This can decrease pod and seed numbers resulting in lower yields.
When pods are formed, canola is more tolerant than at flowering to high temperatures. During seed maturation, temperatures should be warm but not exceed 90 to 95oF for any length of time. A combination of heat and moisture stress at this time reduces seed yield and also oil content. Seed oil content is highest when seeds mature under lower temperatures (60oF).

Winter Survivability
Winter canola undergoes a gradual hardening process after several days of cold, near freezing temperatures that prepares the plant for winter dormancy and allows it to withstand freezing temperatures without serious damage. It is generally agreed that winter canola needs 30 days of above ground growth before the first killing frost to generate enough growth for winter hardiness. Plant growth of six to eight leaves, eight to 10 inches in height and a large tap root (1/2-inch diameter) will develop adequate carbohydrate reserves in the root to help the plant survive. If this establishment does not occur, there is a greater chance of winter kill and loss of the crop. Once established, winter canola is fairly hardy. Snow cover also provides protection and increases chances for winter survival under very cold air temperatures.
Winter survival is severely limited by late planting. In three years of planting date studies at the University of Kentucky, mid-October plantings did not survive two out of the three years; early October plantings did not survive one out of the three years; early and mid-September plantings survived all three years although some loss did occur during a year of very cold temperatures.
Although canola can withstand cold air temperatures, it has been known to succumb in very cold winters with little snow cover. The critical temperatures at which plant damage or kill occurs is somewhat nebulous since other factors such as snow cover, amount of cold hardening, plant developmental stage, soil moisture conditions and other cultural practices influence the degree of susceptibility of plants to temperature. It has been observed that winter canola can withstand 24oF air temperatures with no damage. Below this, leaf damage can occur. In fact, much of the leaf tissue eventually freezes during the winter. Despite the loss of leaf tissue, the plant is not killed if the crown is healthy and alive. In late winter, if you see new leaves or the crown has green tissue, the plant has survived. Usually plant loss will not occur unless temperatures drop below 0oF. In fact, well established plants survived temperatures of -10 to -15oF in December of 1989 with only a 30 to 50 percent stand loss. Some literature suggests that cold soil temperatures (-5oF or less) are more critical to winter loss of canola.
Waterlogged soils seem more conducive to winter loss. On these soils, heaving of smaller plants without an established root system and subsequent exposure of crowns is more likely. It has also been suggested that a combination of waterlogged soils and freezing temperatures promotes the rupture of crowns resulting in stand loss. It has also been noted that fungal or bacterial infections and infestation by fly maggots can cause plant loss in association with freeze damaged or otherwise weakened plants. This phenomenon is known as winter decline syndrome.

Spring Freezes
Freezing temperatures are likely in Kentucky in late March and early April, a time when canola has bolted and may have initiated flowering and pod development. These freezing temperatures have the potential to cause injury. The temperature at which freezing injury occurs varies with the plant's stage of growth, moisture content and the length of time the temperature remains below freezing. The length of time that freezing temperatures occur is important. A large drop in temperature lasting only a short time may not damage canola, while a small drop of a few degrees lasting for several hours may cause severe damage.
Canola is most susceptible to freezing temperatures at flowering. Temperatures just slightly below freezing (31 to 32oF) can kill open flowers, whereas temperatures of 27oF are needed to cause injury on developing pods or unopened flowers (buds). Frost at flowering delays maturity but results in only minor reductions in yield. This is because canola plants initiate more flowering buds than they can develop into pods. Since only about 50 percent of the flowers develop into mature pods, any damage or loss of early flowers or pods causes the plant to recover by development of later flowering buds which would otherwise have been aborted. Frost during flowering usually causes flower abortion only on those flowers open at the time the frost occurred. Frost after the flowering stage, which is unlikely in Kentucky, can result in significant yield reductions.

Hail Damage
Research has shown that canola plants have a remarkable ability to recover from hail damage at certain growth stages. Plants recover remarkably well from damage occurring in early vegetative growth stages. However, in Kentucky hail damage is more likely to occur in the late vegetative and reproductive stages. Plants injured in the late vegetative or early flowering stages can recover because of well-established root systems and the ability to develop secondary flower clusters. When buds and flowers are lost due to injury, the plant recovers rapidly by the development of flowers which normally would have been aborted. Plants can also develop flowering branches from growth buds lower down on the plant and replace, somewhat, the lost buds, flowers and pods. Seed yield depends on the percentage of leaves and branches lost as well as the progression of flowering when the hail damage occurred. The greater the percentage of branches lost, the greater the seed yield loss. Also the longer that flowering has progressed before damage from hail, the greater the seed yield loss. Maturity is also delayed.
If hail damage occurs during pod filling or ripening, plant recovery is greatly reduced. Even if plants do rebranch and flower at this stage, maturity is greatly delayed and redevelopment will likely be hindered by environmental factors (heat, moisture stress). Seed yield losses at the ripening stage depend directly on the loss of branches, pods and seeds.

3. Cultural Practices
(Jim Herbek and Lloyd Murdock)
Field Selection
A medium textured, well-drained soil is best for canola, although it will grow over a wide range of soil textures. Since canola does not tolerate waterlogged conditions, it should not be planted on fields prone to standing water, flooding or poor drainage. Heavy clay and waterlogged soils also increase the risk of heaving if not planted early for a well established root system. Soil compaction, soils that tend to crust and a lack of surface soil moisture at planting time can also affect canola establishment.
Select fields and rotation systems that prevent a build up of pests (insects, diseases and weeds). Allow at least four years between canola crops on the same field. This is particularly important for fields that have been infected with sclerotinia white mold or blackleg and also applies to any adjacent fields. Avoid fields infested with garlic, wild mustard and hard-to-control weeds. Plan ahead so that residual herbicides used on the previous crop do not carry-over in the soil and adversely affect canola. Avoid planting within a mile of a field of industrial rape to avoid contamination which may result in lower seed quality and grade standards.

Variety Selection
Variety selection is important for producing a canola crop that contains desirable performance traits and also quality seed. Plant only those cultivars with canola-quality standards (an oil with less than two percent erucic acid and a meal with less than 30 micromoles glucosinolates per gram). This is essential for canola to be an economically competitive, marketable product. Because of the oil and meal quality differences among the various types of rapeseed, it is important to not plant varieties of unknown or unsubstantiated quality.
Other characteristics to choose in a canola variety are: high yield potential, acceptable test weight (50 lbs/bu), winter hardiness and lodging resistance. Relatively early maturity is also desirable if the canola is to be double-cropped with soybeans. While disease resistance is a desirable trait, there is currently no varietal resistance in canola to most diseases common in Kentucky. However, there is moderate resistance to blackleg in some canola varieties and these should be used in production areas where blackleg is a concern. As varietal development continues, additional disease resistance should be forthcoming.
There are two types of canola available for planting: spring and winter. Spring types are grown in areas where winterkill is a problem for fall seedings. Winter types are fall-seeded and require a specific amount of chilling temperature for vernalization (flower induction). Winter canola fits best into Kentucky's cropping systems, has a higher yield potential and has sufficient cold hardiness to survive most winters.
Most varieties presently sold in Kentucky were developed in Europe. Limited testing and experiences of farmers have shown these varieties to be good and fairly well suited to our conditions. Varietal development is proceeding at a rapid pace and new varieties should have higher yield potential, earlier maturity and improved resistance to shattering, disease, and lodging.
Canola can be hybridized and breeding companies are currently developing hybrids. Some hybrids should be on the market within the next three to five years and should give a 10 to 20 percent yield advantage over current varieties.
The University of Kentucky began to evaluate winter varieties of canola in 1987-88 at the Kentucky Agricultural Experiment Stations at Lexington and at Princeton, Kentucky. Growers interested in an annual performance report of these variety trials should contact the University of Kentucky College of Agriculture or their local county Extension office.

Seed Selection
Only certified seed should be used since it assures you of true canola quality with no contamination from mustards, high erucic acid rapeseeds and weed seeds. It has also been tested for germination and purity to ensure seed quality. Because product quality is critical for canola, producers must be sure of the genetic purity of the seed. Proper seed conditioning and fungicide seed treatments are recommended to avoid certain diseases. In Kentucky, all classes of certified seed must be treated with an approved seed treatment fungicide to control blackleg fungus.
Using bin-run (second generation) seed is risky and does not assure purity, seed quality or that canola standards are met and may result in loss of canola double-low quality. Also to avoid cross-pollination between canola and other types of rapeseed, canola should not be grown in close proximity of the other types.

Certified Seed Production
Certain field, rotation, and seed requirements and standards apply to certified winter canola production. Growers interested in producing certified winter canola should consult the latest "Kentucky Seed Certification Standards" published annually by the Kentucky Seed Improvement Association.

Tillage and Seedbed Preparation
Seedbed preparation is important. Conditions that promote rapid germination and early, uniform stands and growth are important for weed control, winter hardiness and yield. The seedbed should be fairly level, well-packed and moist throughout its depth. The soil surface should have a good granular structure. If the seedbed is too fine (overworked), it can result in loss of surface soil moisture and promote crusting; if too coarse, poor seed placement and moisture loss. Rollers or cultipackers should be used with or after the last tillage operation to firm the soil to allow proper seeding depth and to provide good seed-soil contact.
The no-till method of planting is a means of eliminating tillage for seeding canola. By eliminating tillage, no-till also allows earlier planting.

Planting Date
Canola should be planted in September in Kentucky. Planting dates of September 1 through September 25 should provide the best yields. Seeding too early or too late can increase the likelihood of winterkill. A good rule of thumb is to plant canola approximately four to five weeks before the normal planting date for winter wheat. Planting too early can result in winter injury if bud formation and stem elongation occur prior to winter dormancy. Late plantings (after October 1) reduce yields, increase heaving (due to smaller root system) and reduce winter survivability. Generally, canola needs 30 days (6-8 leaves) before the first killing frost to generate enough growth for winter hardiness. Based on 1989 results, planting date studies showed a 1.7 percent yield loss per day when planting after September 20 but before October 1. Planting after October 1 resulted in a 2.1 percent per day yield loss. Ideal planting dates for optimum yields vary from region to region as plantings move North (slightly earlier) or South (slightly later).
Planting date also effects maturity, canopy cover and weed control. An October planting results in reduced fall foliage production (canopy cover) which can allow weed growth and can delay the harvest date.

Planting Methods
The most common planting methods are broadcast and drilled. The broadcast method can save time and reduce machinery requirements but stand reliability is sometimes reduced using this method. It is very dependent on good surface soil moisture at seeding or rainfall immediately following seeding. The major disadvantages of broadcast seeding are shallow placement of seed, uneven planting depth, poor seed distribution and a greater dependency on moisture. Care must be taken to assure good seed distribution and soil coverage. Working the seed into soil after broadcasting is a critical step. A roller or cultipacker is the most common method and gives good seed-to-soil contact and also retains moisture. This also prevents a deep seed placement problem as other implements can place the seed too deep.
Drilling is the most reliable and preferred method. However, proper drill calibration and settings are required with this method to do a good job of seeding. Advantages of drilling include better seed placement, better seed-to-soil contact and uniformity of stand. Depth placement is important since moisture is usually critical at this time of year and deep seed placement results in failure. Cultipacking is recommended prior to drilling to firm the seedbed and help control the seeding depth.
Grain drills, particularly late model drills, can effectively plant canola through the main seedbox. However, some grain drills may not close down enough for the small seeding rates needed and may require special drive attachments or small seed attachments. Calibration is needed with any seeding method but is particularly essential if using a drill.
Although more difficult, the no-till method of seeding can be used with canola. Use of a suitable no-till drill, proper calibration and no-till planting experience are needed to ensure good stand establishment. Depending on the seed drill capabilities, excessive crop residue on the soil surface can cause uneven seed placement. However, no-till drills that can deliver precise seed depth placement can make no-till planting successful. If the field is heavily infested with weeds or grasses, a contact herbicide at planting would be important for no-till planting. Producers in Kentucky have no-tilled canola into previous crop residue with good to excellent results.

Seeding Depth
Since canola seeds are very small, careful placement is required at a relatively shallow depth. The ideal seeding depth is 1/2-inch in a firm seedbed. The range can be from 1/4- to 1-inch. It is important to plant into moisture within this range, unless rain is imminent. Deeper depths delay emergence, reduce seedling vigor, and delay fall growth and development. It is difficult for canola to force its way through thick soil cover or crusts. At shallower depths the seedbed may dry too fast for uniform germination.

Seeding Rates
Canola is a very flexible plant that can adapt to a wide range of populations due to its ability to branch. Research studies have shown similar yields for seeding rates ranging from four to 10 pounds per acre if an adequate plant stand has been obtained. A harvest population of six to 10 plants per square foot is considered adequate for top yields. Significant yield differences are not usually found unless populations at harvest are under three to four plants per square foot or higher than 15 plants per square foot.
Carefully evaluate before destroying a crop that has a spring stand of only one to two plants per square foot since canola can compensate for wider spacing between plants by promoting branching. In a stand density study conducted at the University of Kentucky, even at one to two plants per square foot, yields were 60 to 70 percent of the optimum yield which occurred at six to eight plants per square foot. These plants compensated by producing more basal branches although they were not as productive as the earlier, main stem branch. Even though plant stands of one to two plants per square foot have given relatively good yields, it is still recommended that seeding rates be utilized to achieve at least five to seven plants per square foot.
Low seeding rates often produce thin stands and result in more weed problems because they cannot effectively form a complete canopy. Although thicker stands can promote earlier and more uniform maturity and thinner stalks which are easier to harvest, populations above 15 plants per square foot do not increase yield, may cause lodging and also increase chances of disease. Higher seeding rates may be used if planting is delayed or when seed placement is affected by surface residue.
The average seed size of canola (Brassica Napus) is about 115,000 seeds per pound (with a range of 80,000 to 150,000 seeds per pound). With average seed size, a five to six pound per acre seeding rate would plant about 13 to 15 seeds per square foot. The percent emergence varies with soil and moisture conditions and seeding methods. Check the seed tag for seed size (seed count per pound) to determine the appropriate seeding rate. The recommended seeding rates are: 4 1/2 to 6 pounds per acre for drilling and 6 1/2 to 8 pounds per acre for broadcast seeding. The higher seeding rate for broadcast seeding is due to expected lower emergence.

Row Spacing
Studies have shown row widths between seven inches and 14 inches to have little impact on yield. Row spacings below seven inches might result in small yield increases under certain conditions. Likewise, row spacing above 10 inches could result in small reductions in yield. The narrower row spacings of six to eight inches provide quicker row closure and reduce weed competition. The six- to 10-inch row spacing provided by most commercial grain drills is acceptable for winter canola production.

Soil Testing
A soil test is the most accurate method of determining the soils nutrient status. Reliable recommendations for phosphorus, potassium and lime can be made from a soil test.

Canola responds to a fairly high level of nitrogen. The present recommendation is 120 pounds of nitrogen per acre. With good stands, lower rates may reduce yields. Higher rates may occasionally result in a higher yield, but it also increases chances of lodging and disease susceptibility. Most or all of the nitrogen should be applied at green up in the spring (March). If possible, it should be applied before budding and stem elongation to prevent damage to the main stem from ground spreading equipment. Ground equipment should never be used when the soil is frozen. Kentucky research shows no benefit for fall application of nitrogen. In many cases, additions of nitrogen in the fall (even in small amounts, 20-30 lb/ac.) increased fall growth and contributed to winter kill. In some years, the winter loss, due to fall nitrogen, has been significant. Large amounts of nitrogen carried over from the preceding crop can also produce the same results. If fall nitrogen is needed for some reason, no more than 30 pounds nitrogen per acre should be added.
A nitrogen deficiency results in stunted growth with a pale green color, early flowering and early maturity. The application of liquid nitrogen could result in scorched leaves, depending on weather and method of application.

Phosphorus and Potassium
Both of these nutrients should be applied in the fall according to soil tests. Recommendations in the following table are based on crop requirements and Kentucky soil characteristics. The recommendations may change as information is gained from research with this crop.
Tentative results indicate that canola is very sensitive to phosphorus and recommendations should be liberal for this nutrient. The crop appears to be less sensitive to potassium and the recommendations can be conservative.

Table 3-A. -- Phosphorus and Potash Recommendations.
Pounds per acre to apply
Soil test level P2O5 K2O
High (above 60P, 300K) 0 0
Medium (30-60P, 200-300K) 0-85 0-40
Low (below 30P, 200K) 85-120 40-80

Canola is sensitive to sulfur deficiency. However, research has not shown a need for sulfur application to this crop or any other sulfur-sensitive crop in Kentucky. If a deficiency is identified, it can be corrected with a sulfur application of 15 to 20 pounds per acre.

For best performance of the canola and succeeding crops in the rotation and for efficient use of herbicides and fertilizers, the pH should be maintained between 6.0 and 7.0.

Fertilizer-Seed Contact
Because canola is sensitive to direct seed contact with fertilizers, nitrogen and potassium should not total more than 10 pounds per acre, if placed with the seed.

Crop Rotation
It is important that canola be in a rotation with other crops. The ideal rotation is to plant canola or other rapeseed or Brassica crops (cabbage, broccoli, etc.) only once every five years to reduce potential pest problems. This rotation helps to minimize the buildup of difficult to control weeds, insects and diseases that continuous planting of canola may perpetuate.
Plan ahead in your rotation systems so that herbicide residues from a preceding corn or soybean crop do not limit your options for planting canola. Canola is sensitive to some herbicides, particularly broadleaf herbicides, depending on the rate used and other factors involved (weather, tillage, etc.). Herbicide residues from Scepter, Canopy, Classic, Pursuit and Atrazine (particularly high rates) can damage canola so caution is advised for planting canola following crops in which these herbicides have been used.
Volunteer canola can be a problem in succeeding crops. However, it can be easily controlled through use of a rotation and use of herbicides in the succeeding crop that are labeled for mustards.
Cropping systems in Kentucky that best lend themselves to canola are set-a-side, fallow and early planted, medium maturity corn.

Conservation Aspects
Ground cover by the canola plant is excellent. If the crop is planted in mid-September, there will be virtually a 100 percent ground cover prior to winter. This cover, along with an excellent root system, protects the soil from erosion as well as or better than a small grain cover crop.
The residue produced from canola is about the same as that produced with small grain, although the seed yields will be about two-thirds to three-fourths that of wheat. The residue appears to decompose more quickly than small grain residue.

Being a winter crop, canola gives Kentucky farmers an alternative to small grains and offers the same double-cropping potential with soybeans. Harvest maturity for wheat and canola are very similar with canola being as much as three days earlier in some seasons. With the tremendous genetic variability available in canola germplasm, earlier maturing varieties may be available in the future which should result in a yield advantage for double-cropped soybeans. Research studies at the University of Kentucky compared soybeans double-cropped after canola and wheat on the same planting date. Two-year results have shown a two to seven bushels per acre yield advantage for soybeans double-cropped after canola as compared to soybeans double-cropped after wheat. No definite conclusions have been reached regarding this yield advantage which has also been reported in studies from other states.

4. Weed Control
(James R. Martin)
Weed control issues that impact canola production in Kentucky include managing problem weeds, herbicide carryover, herbicide drift and volunteer canola.

Weed Management
Both the winter and summer complex of weeds can cause problems in canola in Kentucky. Wild garlic bulblet contamination reduces the market value of canola seed. Common chickweed, yellow rocket and volunteer wheat can overcome canola during the fall or late winter. Johnsongrass may cause harvesting problems in the spring, particularly when canola stands are thin.
Currently there are no weed control programs for a broad spectrum of weed species in canola, therefore, growers must rely on practices that limit the introduction or spread of weeds. Avoid weedy fields, especially those having a history of wild garlic problems. Rotate to other crops in which effective weed control programs are available. Wild garlic and other problem weeds may require more than one year rotation to a crop such as wheat to significantly reduce a heavy infestation. Use weed-free canola seed to prevent the introduction of wild mustard or other weeds.
Preventative measures alone will not eliminate all problems with weeds. Management practices such as early seeding, tillage before planting and use of herbicides are sometimes necessary for weed control in canola.

Seeding Early
Establishing canola early in the season helps avoid competition from many weed species.
The most critical period for weed competition to canola is during the first four to eight weeks after seeding. Canola plants tend to grow slowly during this period and can be overcome by certain weed species.
The peak period for emergence of such weeds as common chickweed and henbit usually occurs from late September through early November. Therefore, seeding in early September may give canola the competitive edge over these weed species.
Seeding early does not necessarily guarantee against problems from weeds. If stress factors such as lack of moisture, poor seeding or herbicide injury inhibit crop growth, canola seedlings may be overcome by weed competition.
Seeding early may also increase the likelihood of canola plants recovering from winter injury and competing against late emerging winter weed complex. Plants that are well established by the onset of winter are likely to survive cold temperatures better and generate new growth quicker than poorly developed plants.

Tillage Before Seeding
In some instances, a light discing a few weeks prior to planting canola may stimulate seed germination of some weed species. The weeds that emerge can then be destroyed by tillage used for preparing the seedbed. This approach may be helpful in cases where problems with volunteer wheat are anticipated.
The potential disadvantage of this practice is that poor stands may occur in cases where tillage causes a significant loss of soil moisture. Shallow discing of the upper two inches of soil should be sufficient to encourage development of wheat and other potential weeds and not dramatically affect the amount of soil moisture.

Chemical Weed Control
Treflan (trifluralin) is the only herbicide currently registered for use in canola in Kentucky. Treflan is applied and incorporated within the upper two to three inches of the soil profile for pre-emergence control of grassy weeds such as cheat.
Canola tends to be shallow rooted during early development and can be injured by Treflan. To ensure against injury from Treflan read and follow label directions. The chance of canola injury may increase when Treflan is applied above the recommended rate or when seedling plants are stressed by soil that is dry or cool and wet.

Herbicide Carryover
The fact that canola is extremely sensitive to many herbicides makes it a good candidate for injury from carryover of herbicide residues in the soil. Developing long-term weed control plans for rotational crops (up to 2 years or longer) may be necessary especially for fields where persistent herbicides are used.
Fields treated with products containing chlorimuron, atrazine or simazine may be more prone to having carryover problems when soil pH is high. Hot spots that occur with overlaps of the spray boom or non-uniform spread of herbicide impregnated fertilizers may also lead to carryover problems to canola.
Listed in Table 4-A are herbicides that have label restrictions that deal with rotation to canola.

Table 4-A. -- Herbicide Rotation Restrictions for Canola as a Rotational Crop.
Herbicide Restriction* Herbicide Restriction*
Accent 10 months if pH << 6.5
18 months if pH > 6.5
Lorox Plus 18 months and successful
field bioassay
Atrazine** 2nd fall following application Pinnacle 45 days
Beacon 18 months Princep 2nd fall following application
Canopy 18 months and successful
field bioassay
Pursuit 26 months
Classic 15 months and successful
field bioassay
Reflex 18 months
Command 16 months Salute 12 months
Commence 16 months Scepter 18 months
Devrinol 12 months Sencor 12 months
Dual 18 months Squadron 18 months
Harmony Extra 60 days Tornado 18 months
Lexone 12 months Tri-scept 18 months
Lorox 4 months Turbo 12 months
*Minimum interval between herbicide application and seeding canola. Always refer to herbicide label(s) for specific information.
** Additional products containing atrazine include Aatrex, Bicep, Buctril/Atrazine, Bullet, Extrazine II, Laddok, Lariat, Marksman, and Sutazine+. Canola injury from carryover of atrazine residues seldom occurs in Kentucky.
Risk of injury may be greatest when using atrazine at a high rate or in fields with a high soil pH.

Herbicide Drift
Drift of herbicides from neighboring fields may lead to canola injury. The growth-regulator-type herbicides such as 2,4-D or Banvel can drift in the form of spray droplets or vapor and injure canola. Canola appears to be most sensitive to these herbicides during flowering.
Caution is needed when applying 2,4-D or Banvel to wheat or corn fields or to fence rows near areas where canola is flowering. Avoid spraying when wind gusts exceed five miles per hour. Do not operate the spray boom at a height greater than recommended by the nozzle manufacturer. Do not treat fields when temperature is expected to exceed 85oF.

Canola -- A Weed in Rotational Crops
Seed loss that occurs with natural shattering at plant maturity and from harvesting process appears to be the major source of volunteer canola in rotational crops. Also, occasional plants that occur along roads, in nearby fields or beneath powerlines are believed to be from seed carried by leaking grain trucks, harvesting equipment and birds.
Controlling the source of the spread is the first step in dealing with canola as a weed. Timely harvest of canola can reduce losses that occur with natural shattering or from bird feeding. Sealing cracks in equipment and covering the grain bed of trucks can help prevent seed loss when transporting grain between the field and the elevator.
Because canola is sensitive to many herbicides, it is fairly easy to control in succeeding crops such as wheat or double-cropped soybeans.
Buctril and Harmony Extra effectively control canola in wheat if applications are made in the fall when canola plants are small. The use of 2,4-D may be preferred for controlling larger plants that have overwintered.
Although canola does not thrive well during the hot summer months there have been instances where plants have caused problems in no-till double-cropped soybeans. Potential problems may occur from seedlings or regrowth of harvested plants. Many soybean herbicides labeled for controlling wild mustard may also control canola.

5. Insect Pests
(Douglas W. Johnson)
Because canola has been grown in Europe and Canada for a number of years, a significant body of literature deals with insect pest problems of those areas. However, very little information exists about insect pests of canola in the United States and virtually none at all deals with the Ohio River Valley production area. As a result, much current thinking about canola insect pests in Kentucky is derived from observations, very recent experiments and opinions that can be reasonably inferred from the existing literature.
As you read about insect pests, remember that very few acres of canola are grown in Kentucky. Because the distribution and concentration of food are major factors in insect population dynamics, the insect pest complex will probably change as acreage increases or becomes more concentrated. Traditionally, increased or more concentrated acres have led to greater and more diverse insect problems.

Insects Present
The first entomological experiments at Princeton, Kentucky were established to take a look at just what insects might be found in Kentucky-grown canola. In general, this plant supports a very large and diverse group of insects, including most of the insects found on the Brassica crops (cabbage, mustards). Fortunately, most species are parasites or predators of other insects and plant feeders of little importance. However, at least three pests are of immediate concern, and two species have a high probability of at least periodic concern. Additionally, remember that this situation will change (probably increase) as acreage increases.

Striped Flea Beetle (SFB)
This insect is a close relative of the tobacco and corn flea beetles but is much larger. The SFB is 1/8-inch long and brown with two yellow stripes down the back. These insects have the habit of quickly jumping away when disturbed. Infestation is limited to the fall.

The striped and other flea beetles use their chewing mouthparts to remove the upper surface of plant parts. This leaves a scared appearance, but not a hole at the damaged location. Canola, like soybeans, is most extensively damaged when this feeding occurs on the cotyledon (seed leaves).

No yield loss is likely to occur unless plants die. There is no established number of SFBs, nor level of damage to trigger treatment. However, as a guideline do not control unless: plants are killed, the number of plants per square foot falls below the recommended minimum and live feeding SFBs are still present.

"Canola" Aphids (CA)
A large number of aphid species are found on canola (e.g. red turnip, cabbage, etc.). Currently, green peach aphid is the most common aphid known to infest, debilitate and, under some conditions, kill canola plants in Kentucky.

Green peach aphids are small (1/16-inch), tear drop shaped, soft bodied insects. They are usually found in colonies on the underside of leaves. (Aphids are attracted to the color yellow, so look at yellowing leaves first). Most aphids are wingless, though a few have wings and these winged individuals (usually <<10% of the colony) spread the infestation within and among fields. This particular group of aphids contains both green and red (rusty brown) forms and looks very much like the tobacco aphid.

Aphid problems usually occur in the fall on small plants. However, scattered but very large infestations have been observed in the spring, mainly on main stem pods. Aphids feed by sucking plant juices through their piercing-sucking mouthparts. No noticeable physical damage may be seen. Usually, when substantial damage occurs, the plant takes on an unthrifty appearance, wilts or changes colors.
Warning: Canola may take on a purple and or yellow color due to winter stress. Aphids are attracted to yellow and may congregate on yellow leaves which are normally older, lower on the plant and less thrifty. Aphids' presence on these leaves does not necessarily indicate that the aphids caused the color.

There is no established number of aphids per plant nor percent infested plants that triggers a control situation. However, control may be warranted if: infested plants show an unthrifty appearance when compared to uninfested plants in a similar situation, a large number of live aphids (one or more colonies per leaf) are present, and the plant population is in danger of falling below the recommended minimum per square foot.
Aphid populations are often very spotty. In many cases border or spot applications provide very adequate control.

Cabbage Seed Pod Weevil (CSPW)
Kentucky has this pest in common with many other canola production areas. CSPW is the most common target of about 15 state SLN labels across the United States and is also listed as a pest in both Canadian and European literature.

CSPW is a small weevil which feeds on flowers and pods of canola and several other mustard plants. The beetle is actually black but appears gray because of its body hairs. When wet, it looks black. It has chewing mouthparts on the end of a long curved snout. This snout is easy to see even though the insect is quite small.
The beetle is probably active on alternate hosts early in spring. CSPW moves into canola at bloom and stays, feeding on the blooms (which does no damage) and then laying eggs on the pods. The pod damage may affect yields.
In the normal weevil fashion, an adult female CSPW bites a hole in the surface of developing pods. It then turns around and puts an egg into this cavity and once again turns around to replace part of the plant material, thus covering the egg. The egg hatches and a CSPW grub burrows its way into the pod's interior, where it feeds on developing seeds until it matures. The final larval stage CSPW grubs chew their way out of the pod, drop to the ground, pupate and emerge as adults.

Damage results from grub feeding and waste production inside the pod. No external sign of damage exists until the pest has completed its life cycle and chewed its escape hole in the pod wall. Normally, only one grub is in each pod and often only a portion of the seeds in an infested pod are damaged.

This question is very difficult to answer. Ward et al (1985) suggest implementing control when populations reach two CSPW per plant. To examine the plant, observe it closely or tap the main raceme over a tray.
Another method is to use a standard 15-inch insect sweep net. McCaffrey (1986) suggests that thresholds will be very low (2-3/sweep) and that controls should be applied after full bloom but before bloom ends.

Pests Resulting from Specific Conditions
Poorly Drained Soils
Several Kentucky producers have suffered extreme loss in plant stands and at first the cause was unknown. This problem, commonly known as Winter Decline Syndrome, could have several causes (Refer to Diseases -- Stress Related Disease Complex for other causes). Water saturated soils were a common factor in these cases and examination revealed small fly maggots and pupae. Species identification has not been established, but they are probably flies from the genus Delia. Delia radium (L.) the cabbage root fly and D. platura (Meigen) the seed corn maggot are likely culprits.
No thresholds or treatments are known. Canadian research indicates that these pests are common and are not important under good growing conditions. But under stress, especially water saturated soils, this insect is extremely important with no rescue control available.

Drought contributes to a complicated set of pest problems. Three conditions produce a perfect situation for infestation by the false chinch bug: drought, canola production, and double crop, no-till soybeans. The actual damage is to soybean seedlings but the heavy residue left from canola production produces the environment. Drought conditions favor false chinch bug development and slow soybean growth.
This combination has seriously damaged soybeans in Kentucky. However, in all production years when one or more of these factors were absent, no infestation occurred. It is very likely that drought is the most important of these factors.

It appears that application with an insecticide with known soil activity gives the best results. Plants are growing too slowly for systemic soil insecticides to have much effect and are too small for treatment of only the plant. For best results, use a broadcast spray with a lot of water, which saturates the canola residue, forcing the false chinch bug to crawl through a layer of insecticide residue.

Insecticidal Treatments
Synthetic Chemicals
As of this writing, no chemical insecticides have a national label for use on canola, but several states do have special use labels. One chemical insecticide is labeled for use on canola in Kentucky: Thiodan 3EC, which is a product of FMC Corporation (EPA SLN No. KY-890002).
This compound has a special local need label (commonly called SLN or 24C) issued in 1989 for use in Kentucky. To use this compound, you must have a copy of the SLN label in your possession at the time of application.

Biological Controls
Microbial insecticides containing the bacteria Bacillus thuringinsis (B.t.) may also be used. At present, however, using B.t. does not help Kentucky's producers much because B.t. compounds only affect caterpillar pests, which are not yet a problem on canola. (Caterpillar pests are juveniles of butterflies and moths, e.g., diamond back moth and cabbage worm on cabbage.)

Summary and Recommendations
Several current and potential insect pests exist on Kentucky-grown canola. The number of pests is likely to increase as production increases and becomes established. There are no insect pests currently or likely which would prevent the economic production of canola in Kentucky although developing a comprehensive pest management system will be important to economically protect this crop.
Producers should be aware that increasing acreage, compacting distribution, continuous cropping history and use of unrecommended fields and practices will likely increase insect pest significance. To that end consider the following recommendations:
1.Plant only on recommended (especially well-drained) soil.
2.Follow all recommended agronomic practices to produce fields with vigorous plants and a stand of six or more plants per square foot.
3.Rotate the field and locations if possible on the farm. Try not to plant near other rape fields.
4.Control all volunteer rapes and other Brassica sp. weeds (wild mustard, yellow rocket).
5.Scout the crop weekly and more often as infestations arise.
6.Watch for insect pests in following crops, especially soybeans.
7.Use only legal insecticides. Remember that canola is a food for human consumption.

McCaffrey, J.P. Pest management of winter rape under dryland conditions. Proc. 1986 PNW Winter Rapeseed Production Conf. Moscow, ID Feb. 24-26, 1986.
Ward, J.T., W.D. Bashford, J.H. Hawkins and J.M. Holliday. Oilseed Rape. Farming Press Ltd. Ipswich, GB. 1985. 298 pp.

6. Diseases
(Donald E. Hershman)
Canola is susceptible to attack by disease organisms any time from seeding through maturity. These organisms originate from many sources including soil, infested or infected seed, infested crop residue, or air-borne spores blown in from volunteer canola plants, certain weeds, neighboring fields of canola, and related vegetable crops or other crop plants.
Although canola has a short history in Kentucky, many of the disease organisms that affect canola have been here for a long time. We know this because these organisms also attack other brassicas, both cultivated and weedy, and other common crop plants in Kentucky. While many of these disease organisms are presently at low levels, intensive cropping of canola may provide for their rapid build-up. Then, given the proper environmental conditions, the development of serious disease epidemics in the canola crop are possible. Crop failures due to disease have already been documented for two pathogens.
Growers need to follow strict crop management practices to reduce the chances of the development of serious epidemics and to provide for the continued growth of the canola industry in Kentucky. This section provides information on the biology and control of the most serious or common canola diseases in Kentucky.

Major Diseases
The following canola diseases have been documented in Kentucky and have great potential for causing serious crop losses.

Sclerotinia Stem Rot (Sclerotinia sclerotiorum)
Sclerotinia stem rot (white mold) is a serious problem of canola in many areas throughout the world. The most severely affected areas are those which regularly experience extended periods of wet weather while canola is in flower. Under heavy disease pressure, yield losses of 50 percent or more are common. On average, percent yield loss is equal to about half the percent of stems infected.
Severe episodes of the disease were first confirmed in several areas of Kentucky in 1989. However, serious losses due to stem rot are thought to have occurred as early as 1987.

Symptoms and Signs
Symptoms of stem rot appear in Kentucky from May onwards. The disease is characterized by narrowly elliptical, slightly sunken, light tan to gray lesions usually in the mid- to lower stem. Hard, irregularly shaped (1/8- to 1/2-inch long x 1/8- to 1/4-inch wide), black resting bodies of the fungus (sclerotia) are found within the stem cavity of affected plants. Sclerotia may also develop on the outer stems of plants under extremely humid/wet conditions and in the upper taproot.
Plants infected late in the season, after most pods have developed, may lodge due to stem breakage but experience few other yield effects. However, when plants are infected during the early to mid-flowering stages, plants may have fewer pods, fewer seeds per pod and smaller, shriveled seed. These plants ripen prematurely and suffer severe lodging. Crop lodging greatly slows the harvesting process and increases yield losses due to shattering.

Disease Development
Sclerotia fall to the ground during harvest or as stems break when lodging occurs. From mid-April to mid-May, sclerotia in the upper one to two inches of soil germinate to produce small golf tee-shaped structures called apothecia. Sclerotia buried deep in the soil remain dormant (8 years or longer) until brought near the surface by cultivation. A single sclerotium can produce from one to 15 apothecia.
Apothecial formation on individual sclerotia can occur all at once or over a period of weeks; the process requires that soil moisture levels be high and temperatures low to moderate for at least 10 consecutive days. Both cooler temperatures and adequate soil moisture are favored within dense, vigorously-growing canola stands and within thinner stands with heavy weed pressure. Canopy density also affects the length of time that individual apothecia remain active.
Apothecia release spores (ascospores) during wet weather and periods of heavy dew. The spores are blown to and infect flower petals of canola plants. Ascospores can be blown into a crop from a relatively distant source, however, the most important source of stem rot inoculum comes from within a field or from immediately adjacent fields and areas. Infected, fallen petals that lodge on leaf surfaces, in leaf axils and on plant stems then serve as sites where the fungus moves into the main stems of plants during wet or humid conditions. Ascospores are unable to infect canola plants directly. Conversely, direct infection of stems as a result of sclerotial germination, without apothecia or ascospores being produced, has been documented in more southern production areas. Once plants are infected, symptoms of stem rot appear after about 10 to 14 days.

All canola varieties are susceptible to Sclerotinia stem rot. Apparent differences in susceptibility are related to varying temperature and moisture conditions during the different flowering periods for the varieties and not to disease resistance mechanisms.
The control of Sclerotinia stem rot in Kentucky is difficult for a variety of reasons. The most notable of these is the wide distribution of the causal fungus and the frequent occurrence of conditions favorable to stem rot during the period that canola varieties flower in Kentucky. Because of this, the moderation of stem rot problems is only possible when growers are consistent in the implementation of a specific set of management practices. The use of any single measure frequently results in unacceptable levels of stem rot in production fields.
Not growing canola or other stem rot susceptible crops in a field or nearby fields more frequently than one in five years helps limit the build-up of the stem rot fungus where low levels of the fungus currently exist. The stem rot fungus can infect 145 plant genera and literally hundreds of species. As a result, selection of an acceptable non-host crop is very important. In Kentucky, wheat, barley, corn, milo and other grass crops are good choices. Soybeans, while susceptible to stem rot, rarely develop the disease in Kentucky because late spring and summer conditions are usually not supportive of disease development. Thus, soybeans appear to be an acceptable non-host crop in canola production areas in Kentucky.
The value of crop rotation is greatly diminished where high pathogen levels are being maintained in and around fields infested with stem rot susceptible weed hosts such as field pennycress, shepherd's purse, wild mustard and related species. In these situations, crop rotation of canola must be coupled with the use of cropping systems and weed management practices, in off-canola years, which limit the development of stem rot susceptible weeds. Even where these practices are strictly followed, the danger of a serious stem rot problem still exists due to the possible movement of spores from adjacent farms where these practices are not followed and from nearby tree lines, fence rows, pastures and fallow areas which are heavily infested with weeds susceptible to stem rot. This is much less of a factor the further away poorly managed farms and non-crop areas are from properly managed canola fields. This is due to the fact that most spores which cause severe stem rot problems come from within or nearby the field, rather than from significantly distant sources.
In addition to crop rotation, other cultural practices may help to moderate stem rot problems. Plowdown of stem rot-infested residue, immediately following canola harvest or after double- cropped soybeans are harvested, buries sclerotia and reduces apothecial production in the next crop. For plowdown to be effective, subsequent crops must be planted using minimum or no-tillage practices so that sclerotia are not returned to the soil surface. Also, planting more than one canola variety greatly reduces the chances that all the acreage will be involved in a stem rot epidemic. This is because each variety has a slightly different flowering period and it is less likely that stem rot favorable conditions will exist during the early to mid-bloom periods for each of the varieties grown.
Further help can be achieved by avoiding excessive canopy density in canola by using proper seeding rates and adequate, but not excessive, nitrogen. This promotes air circulation and light penetration into the canopy and reduces the time that conditions are optimal for spore production, spore release and infection by the stem rot fungus. The management of weeds in canola fields is also important as an excessive weed canopy provides an exceptional environment for the fungus to develop. This can result in high stem rot levels even when the canola canopy is not excessive.
Foliar fungicides, applied in the early to mid-bloom stages, are used throughout the world to combat stem rot of canola. In 1991, Kentucky was granted a specific exemption by the Environmental Protection Agency for the use of Benlate 50DF and 50WP in the control of this disease. Test results and observations from treated areas show that stem rot levels and yield reductions can be greatly reduced when a single application of the material is applied at 30-40% bloom. Future labels for this product and others under investigation should ultimately prove to be an invaluable tool in the management of stem rot.

Blackleg (Leptosphaeria maculans [anamorph = Phoma lingam])
The blackleg organism is common worldwide and infects canola and related crops wherever they are grown. The fungus is highly variable in its ability to cause disease with some strains being highly aggressive and others being weakly aggressive. The latter group is the most common worldwide, but is considered to be of minor importance. Highly aggressive strains of the fungus exist in pockets in some countries and cause severe losses.
In the spring of 1989, a highly aggressive strain of the blackleg fungus caused 75 to 90 percent yield losses in several production fields in southeast Logan County, Kentucky. This was the first report of a blackleg epidemic caused by the aggressive strain of P. lingam in canola in the United States. Subsequently, the highly aggressive strain of the blackleg fungus has been shown to occur in North Dakota, north central Tennessee and in southern portions of Indiana, Illinois and Michigan. However, Logan and, as of 1990, Simpson counties, Kentucky and three North Dakota counties are the only counties in the United States to have experienced serious blackleg epidemics in canola.
The source of the aggressive strain in Kentucky is unknown. Contaminated seed brought in from outside Kentucky is the most likely source, however, indigenous populations of the aggressive strain may have existed on crops such as mustard greens or other brassicas before canola was introduced into the area.

Symptoms and Disease Development
The fungus survives at low levels in infected and infested seed (up to 3% of seed harboring the fungus), in infested, woody canola stubble and in certain weedy hosts. Fungal inoculum released from stubble, and not diseased or infested seed, is most responsible for initiating serious blackleg epidemics. Thus, in production areas already infested with the blackleg fungus, seed transmission is relatively unimportant. However, the use of diseased seed in uninfested areas is the principal means of spreading the fungus to new production areas.
The fungus in infested stubble develops two types of spores: ascospores and pycnidiospores. The former are the primary source of blackleg epidemics. Ascospores are forcibly ejected from stubble and may travel in wind currents as far as three miles from the original source. Under Kentucky conditions, the most prolific spore release occurs from first-year stubble from June through March or April, depending on the year. Spore production drops significantly in second-year stubble and is essentially non-existent in third-year stubble.
Ascospores blow into a field and infect plant foliage during periods of wetness. Symptoms readily develop at temperatures ranging from 59 to 84oF. The resulting spots are light green to off-white in color and circular to irregular in shape. Spots become papery-thin and buff color with age, and bear numerous, black, pimple-like structures called pycnidia. Pycnidia are the source of pycnidiospores. During rainy weather, these spores are splashed from pycnidia for short distances and can result in secondary spread of the disease within a field.
Infected stems develop cankers which are oval in shape, light brown to tan in color, and with a purplish margin. As with leaf spots, pycnidia are present in mature blackleg cankers. While cankers can develop anywhere on plant stems, it is the girdling, basal stem cankers which contribute most towards serious crop losses. Cankers of this type cause premature plant death and severe lodging.
Stem cankers resulting from direct infection of stem tissue by ascospores or pycnidiospores is uncommon. The more common means of stem infection results from the movement of the fungus from infected leaf tissue, down the leaf petiole and into the stem. Thus, foliar infection is essential if significant stem infection is to occur. Once the fungus reaches the stem, disease development ceases until the fungus is exposed to temperatures of 64 to 68oF for two to five weeks. At that point disease development resumes and a canker is formed. Because of this latent period, cankers typically develop in mid-spring after plants have flowered and after they have lost their capacity for compensatory growth. Plants are susceptible to this means of stem infection up to the six-leaf stage. Plants infected after this stage may develop foliar symptoms, but no or very limited stem cankers. In Kentucky the six-leaf stage is usually, but not always, reached prior to plants entering winter dormancy.
Symptoms resulting from infection by the blackleg fungus of pods and related structures generally resemble those of stem infections, but are of a reduced size. Seed may be diseased without any external evidence of pod infection. Infected seed may be discolored and/or shriveled, or may be symptomless. Pod/seed infections are usually initiated by pycnidospores, although infection by ascospores may also occur. Infected and infested seed produce seedlings with lesions and pycnidia.
Yield loss due to blackleg infection in canola is the result of premature plant death, pod shattering, reduced seed size and weight, and plant lodging.

Disease Management
In most areas of the world, blackleg is kept in check through the use of resistant varieties. In the United States, great headway is being made in the breeding of suitable blackleg-resistant varieties, however, the majority of canola varieties currently available to producers are completely susceptible to blackleg. Moderate resistance/tolerance to the disease is available in a small number of newly released varieties. These varieties should be used in areas where blackleg occurs or is a concern.
Using the following cultural measures, while not eliminating the threat of blackleg, should reduce the spread of the disease to new areas and limit its seriousness in production areas where blackleg already exists.
Bury diseased stubble by deep plowing before canola emerges in neighboring fields in the fall. This is useful because the fungus survives in woody canola stubble and is the main source of infective spores.
Where soybeans are to be double cropped following a blackleg-infected canola crop, deep plow the canola stubble before planting soybeans. Waiting to plow until after soybeans are harvested is not acceptable. This is because newly seeded canola in neighboring fields will be up and growing before soybean harvest is complete and before deep plowing would be possible.
Following deep plowing of stubble from a blackleg-infected canola crop, use minimum tillage or no-tillage practices in subsequent crops to avoid bringing infested stubble back to the surface.
Isolate newly seeded canola as far as possible from the previous years' canola crop. Planting canola in the same or adjacent fields within three years of a previously diseased crop negates the value of deep plowing.
Sow only certified seed treated with a fungicide effective against blackleg. Do not use saved seed, even if it has been treated with a fungicide. This is important because infested seed is the primary means of bringing blackleg into a previously uninfested area. Currently, benomyl is the only material registered in the United States for this use.
Thoroughly clean any equipment used in blackleg-infested fields before moving the equipment to other fields or farms where the blackleg fungus does not exist.
Use multiple planting dates when possible. Plants are highly susceptible to blackleg only up to the six-leaf stage and when conditions are favorable for disease development. Using more than one planting date increases the probability that at least a portion of the crop will escape serious damage.
Where practical, control cruciferous weeds in and around production areas which may harbor the blackleg fungus.

Alternaria Black Spot (Alternaria spp.)
Alternaria black spot, also called dark leaf and pod spot, is common wherever rapeseed or canola is grown. Depending upon the location, the species of Alternaria which cause damage are variable. In Canada and possibly in the northern United States, A. brassicae and A. raphini are the principle disease organisms. In western Europe, the disease is usually the result of infection by A. brassicae and to a lesser extent, A. brassicicola. In Kentucky and the lower midwest, the main pathogen appears to be A. brassicicola. All of this variation as to the causal organism results in considerable variability in the epidemiology and the symptoms of the disease from year to year and location to location.
In England, Alternaria black spot is the most consistently serious disease of rapeseed. In Canada, while present at low levels in most years, severe instances of the disease have reduced yields by as much as 20 percent. Yield losses are primarily due to seed shrinkage and shattering. Severe instances of Alternaria black spot have occurred only sporadically in Kentucky, however, a high incidence of low levels of the disease suggests that it has the potential to become a more serious problem as canola acreage increases.

Symptoms and Disease Development
All above-ground plant parts are susceptible to infection. The most common symptoms, however, are found on the leaves, pods and stems supporting the pods. Leaf spots can be found any time the crop is in the ground and range from small black spots the size of a pinhead to larger spots with concentric rings up to 1/4-inch in diameter. The color of spots is highly variable ranging from gray to black, depending on the weather. Spots may or may not have a purplish to black border. The most serious phase of the disease occurs when infections spread to newly set pods. Spots similar in appearance to leaf spots discolor and weaken the pods and seed. This results in premature ripening and seed shrinkage followed by shattering.
The fungus overwinters in infested crop residue, on or in seed and in certain weeds such as wild mustard. When infected or infested seed are sown, seed may rot in the ground or produce diseased seedlings. Plants can also be infected by wind-blown spores emanating from diseased canola stubble, neighboring canola crops or susceptible weeds crops. Warm, humid conditions favor disease development. Spores germinate, penetrate plant tissue and cause lesions in a span of a few days. These lesions produce new wind-blown spores which cause new infections on the same or neighboring plants.

All varieties of canola grown in Kentucky are susceptible to Alternaria black spot. Early maturing varieties may be more affected because of disease-favorable weather conditions during maturation.
Plant well-cleaned seed to reduce the seed-borne levels of the black spot fungi.
Allow at least four years between canola crops in a field and keep susceptible weeds and volunteer canola to a minimum during this period.
Dispose of the previous year's canola stubble through deep tillage.
Control Sclerotinia stem rot and insect damage where possible.
In heavily diseased crops, timely harvest may prevent serious losses due to shattering.

Minor Diseases
The following canola diseases are known to occur in Kentucky, but are presently considered to be of minor importance.

Gray Mold (Botrytis cinerea)
Gray mold occurs worldwide on many different crop plants. Infections usually occur on tissues damaged by frost or other agents such as insects or fertilizer. However, the fungus can infect undamaged plant parts when these come in contact with infected tissue. All aerial parts of canola plants are susceptible to attack by B. cinerea. Avoiding crop damage is the surest way to reduce losses due to gray mold.
Gray mold can be recognized by the development of a fuzzy, gray mold on injured tissues during humid or wet weather.

Powdery Mildew (Erysiphe cruciferarum)
Powdery mildew is presently a minor disease of canola in Kentucky. In some production areas (eg, south Georgia), however, powdery mildew has resulted in serious yield losses under limited production conditions. These yield losses have been associated with fall or very early spring development of the disease. In Kentucky, powdery mildew develops in the canola crop well after flowering, usually in late May. Earlier development, however, is possible and the disease may become more important as Kentucky's canola acreage increases.
Powdery mildew can be recognized by the white dusty growth of the causal fungus on all above-ground plant parts. Generally the disease is favored during periods of moderate temperatures and high humidity. High nitrogen fertilization and excessive canopy density are also favorable to the development of powdery mildew.

Downy Mildew (Peronospora parasitica)
The downy mildew fungus causes yellowing in irregular patches on upper leaf surfaces; this frequently gives the leaf a stippled appearance. Areas on the undersides of leaves corresponding to the yellow patches on the upper surface have a white, somewhat granular appearance. Affected areas usually become bleached with age. The disease is occasionally seen as sparse wefts of fungal growth on stems and pods. In Kentucky, downy mildew usually shows up in the crop following spring infections, which cause little damage. More severe damage, generally in the form of reduced winter hardiness, is usually associated with seedling infection in the fall.
Occasionally, a disease known as staghead is seen in some canola fields. Staghead is the result of dual infection by the downy mildew fungus and another disease organism, Albugo candita. Albugo candita is the cause of a minor, but common, disease called white rust. When both fungi infect canola, the terminal parts of flower stalks turn brown and hard and dry up. Portions of individual flowers may also become distorted.

Black Rot (Xanthomonas campestris)
Black rot is a bacterial disease which affects canola. Infected leaves develop a bright yellowish discoloration in their margins. Leaf veins in infected areas appear dark in color. The causal bacterium is seed-borne and overwinters in infested canola stubble and in residue from other susceptible crops. Bacteria enter pores in leaf surfaces during periods of wind and splashing rain.
Although the symptoms of black rot are quite visible and can cause great alarm to the producer, the disease up to now has not caused significant damage to canola in Kentucky.

Damping-Off Diseases (Pythium spp. and Rhizoctonia solani)
Pythium and Rhizoctonia occasionally cause damage by rotting seed or seedlings shortly following germination. Losses, while rarely serious, usually occur when seeds are planted under adverse soil conditions, especially excessively cool and wet soils. Planting seed too deep may increase the incidence of damping-off. The risk of damage due to damping-off can be greatly reduced by avoiding adverse soil conditions when planting. Using fungicide seed treatments such as captan or benomyl offers only limited protection against damping-off diseases.

Aster Yellows (Mycoplasma-like organism)
This disease is caused by an organism that is somewhat intermediate between a bacterium and a virus; it is quite common and can affect at least 300 plant species. The organism is apparently spread during the feeding activities of leaf hoppers.
Infected plants fail to set pods or they develop sterile, hollow bladders in place of normal pods. Although symptoms due to aster yellows are quite noticeable, serious yield damage due to the disease is rare.

Stress Related Disease Complex
Winter Decline Syndrome
Some canola producers have experienced the gradual reduction of winter canola stands during late winter and early spring. The tap roots and crowns of affected plants deteriorate, often becoming hollow, and the plants may die. Plant death can occur either prior to or after bolting, depending upon the timing and degree of damage. Some affected plants bolt normally, but suffer lodging later in the season due to weakened crown tissue. Occasionally, affected plants remain upright, but die prematurely with a greatly reduced seed yield. Stands can be reduced by over 90 percent in severe cases.
Various soil-borne bacteria and fungi have been isolated from affected tissue, but with no consistent patterns. In addition, affected roots are frequently, but not always, infested with maggots (refer to insect chapter for more information on maggots relative to this complex).
The exact cause of winter decline syndrome is unknown. However, field observations suggest it is the result of physical damage that provides ports of entry for maggots and secondary disease organisms. Physical damage to roots and crowns is thought to involve sub-lethal, low temperature damage to plants not adequately cold-hardened, or that break dormancy prematurely in the spring. Plant heaving during freeze/thaw cycles and soil/oxygen depletion resulting from water-logged soils may also be contributing factors.
The best way to control winter decline syndrome is to plant canola only into well-drained soils and follow production practices that result in adequate fall growth, which promotes winter survival. Observed differences among cultivars with respect to winter decline syndrome may be related to different degrees of physical damage which, in some cases, may have a genetic basis.

Anonymous. 1986. Blackleg of Canola. Agdex 149/162-3, Alberta Agriculture, Edmonton, Alberta, 4 pp.
Gabrielson, R.L. 1983. Blackleg disease of crucifers caused by Leptosphaeria maculans (phoma lingam) and its control. Seed Sci. & Technol. p 749-780.
Evans, E.J. (Ed). 1984. Control of pests and diseases of oilseed rape. MAFF(ADS) Booklet 2387, London, England, p. 24-49.
Hill, C.B., D.V. Phillips and D.E. Hershman. 1992. Canola winter decline syndrome. (Disease Note). Plant disease, Vol. 76 (In Press).
Hill, C.B. 1991. Blackleg of crucifers. In Plant Diseases of Economic Importance, A.N. Mvkhopadhyay, Editor. Prentice Hall, New York, NY.
Thomas, P. 1984. Canola Growers Manual. Canola Council of Canada, Winnipeg, Manitoba. p. 1034-1063.

7. Harvesting, Drying and Storing
(Samuel G. McNeill and Douglas G. Overhults)
When to Harvest
Canola ripens quickly making timely harvest extremely critical for maximum yield. The seed reaches physiological maturity at about 40 percent *All moisture contents are given in % wet basis (wb).moisture content* and begins to turn from green to yellow, brown, or black. Once the pod is filled, seeds dry rapidly at a rate of one to three percent per day depending on weather conditions. Harvesting too early results in too many green seeds and light test weight while late harvesting results in excessive shattering and yield loss. Late harvest also increases the potential for weather related delays and for lower soybean yields for double crop producers. Direct combining and swathing are widely used for harvesting canola in most areas. Desiccants are often used in a wet season to speed drying and reduce shatter losses in other production areas but presently are not registered for use on canola in the United States.
Monitor the number of green seeds in the field, the moisture content of the canola seed, and the presence of dew or surface moisture on the plant to determine when the crop is ready to combine. A recent report that summarizes a three-year rapeseed harvest study in Georgia indicates the following correlation of seed color to moisture content:
Seed Color1 Seed Moisture (%wb)
All G - 10 % Y, Br, Bl 40 - 50
30 - 40 % Y, Br, Bl 30 - 35
All Y, Br, Bl 20 - 30
1G = Green; Y = Yellow; Br = Brown; Bl = Black. Univ. Ga. 1991.

Most portable electronic meters can test for moisture content with sufficient accuracy using charts for canola. Check the manufacturer's manual for information on obtaining specific charts, or compare the readings from your meter with the meter at a grain elevator. The optimum harvest moisture for direct combining is nine percent, however, the crop can be cut and laid in a swath at moisture as high as 35 percent.
Shatter losses generally are lower when the seeds are relatively green. Bear in mind that green seeds stay green once the crop is harvested. Also, elevator dockage associated with green seed can offset the yield increase from an early harvest.
To test for the number of green seeds, gather a total sample of 100 seeds from three to four locations in the field. Place them on the sticky side of a piece of tape to hold them in place. Press the tape with the sticky side down and crush the seeds with a wooden rolling pin. Count the number of seeds with a distinctly green interior. If this number is more than two (2% of your sample), wait a day or two and make another count. Since canola ripens from the bottom of the stalk up, check every two to three days after some color change is noted in the pods on the bottom of the main stem.
The Georgia study investigated two harvesting methods (swathing vs direct combining) and two combine header types (conventional auger vs draper table). Draper table-type combines are commonly used in Europe and have a belt conveyor behind the cutterbar to transfer material into the thrasher.
Comparisons of the yield data for the three-year study indicate that the draper table combine outperformed the swathing unit. The order of machine preference for higher yields and lower machine losses was 1) direct combine with a draper table, 2) swather and 3) direct combine with conventional auger.
Higher yields were obtained by both harvest methods when some seeds were relatively green (70-90% dark seed for direct combining and 50-70% for swathing). Elevator dockage for green seed may offset the increase in yield, however. Machine losses were higher than normal in this study, averaging nearly 40 percent for both swathing and direct combining. Seed losses were 30 and 50 percent for the draper table-type combine and the auger-type combine, respectively.
The presence of moisture on plant material is just as important as seed maturity in controlling machine losses. Harvesting after a heavy dew or at night exclusively may be the best conditions for reducing losses. Otherwise, ground speed and combine settings must be checked and adjusted throughout the day as plant material dries to control losses to acceptable levels.
Short vertical side knife sections mounted on the outside of the header are proven additions in avoiding excessive crop losses for severely lodged or tangled crops. Mechanical, electrical or hydraulic driven units are available to fit most all combines.

If the proper equipment is available, canola can be swathed when the crop reaches 35 percent moisture content in the field. A visual indication of this condition is when about a third of the seeds have turned a dark brown color. Reserve nutrients in the stem and leaves are sufficient to complete seed development.
The swath should be placed on top of the stubble where it will dry in approximately one to two weeks or even less under hot, dry weather. When the seed has dried to nine percent, the crop can be threshed and stored. Other suggested guidelines for swathing are:
1.Check the operator's manual for specific machine settings.
2.Swath the crop when 30 to 35 percent of the seeds on the main stem only have changed color.
3.Set the cutter bar about eight to 12 inches above the ground or just below the bottom seed pods.
4.Swathers should have a table depth of 39 inches or more, a throat width of 39 to 51 inches, and a vertical clearance of 29 to 39 inches to handle the bulk.
5.Crop dividers or vertical knives may be required to operate in a heavily lodged crop.

If swathing late (when more than 50% of the seeds on the main stem have changed color, or when the seed is 20-25% moisture content), swath after a heavy dew or light drizzle to reduce shattering losses. Typical ground speeds for swathing are between two and three miles per hour (mph). See the section on machine adjustments for threshing the swathed crop.

Direct Combining
Direct harvesting can begin when crop moisture has reached nine percent or within one to two weeks after swathing. The time lag depends primarily on weather factors, but the combine should be ready to go to the field quickly in case unfavorable weather conditions develop. Conventional and rotary combines are effective for harvesting canola if properly adjusted. Ground speed usually is in the two to three mph range for good uniform stands.
Refer to the operator's manual for specific machine settings for canola (or rapeseed) prior to going to the field. In absence of specific information in the operator's manual, the following settings may be used as a starting point.
1.Rotor/cylinder speed: 450 to 600 rpm
2.Concave clearance:
Conventional: 1/2 to 1" front, 1/8 to 3/4" rear
Rotary: 1/2 to 1 1/2"
3.Fan speed: 400 to 600 rpm
4.Chaffer setting: 1/4 to 3/8"
5.Cleaning sieve: 1/8 to 1/4"

From this starting point, experience and field conditions should be used to make further adjustments.
Machines with rigid cutter bars should have the cutting height set just below the seed pods. Cutting too low on the plant stem can reduce ground speed, increase surface moisture on the seed and unnecessarily increase the amount of material that must be handled by the machine.
For combines equipped with a pick-up attachment, equalize the pick-up speed with the ground speed to minimize shatter losses at the header. The auger should be set just low enough for an even flow of material from the table.
The reel should be set high initially and as far back over the table as possible. In the field, lower the reel slightly towards the crop just until smooth feeding is accomplished. Match reel speed to ground speed to minimize shatter.
Cylinder or rotor speeds should be set at about one-half to two-thirds that used for wheat, depending on crop conditions. Under proper conditions, the speed should be set just fast enough to break open the pods. Reduced speeds are important to prevent overthreshing pods and stems and overloading the sieves.
Set the concave clearance to minimize the amount of broken material (pods and stems) passing over the sieves that interferes with seed separation. A 3/8- to 1/2-inch clearance should be sufficient to minimize losses. Open the front concave clearance fairly wide (up to 1 inch) if excessive losses occur.
Few adjustments can be made to straw walkers to improve seed separation. Unthreshed pods, broken pods and straw returned from the straw walkers tend to overload the sieve and return augers. Some farmers install a 1/4-inch screen over a portion of each straw walker to help improve separation.
The chaffer (top sieve) should be opened enough for good separation. Unlike other grains, the cleaning action for canola should rely more on a shaking action for separation and less on wind separation. Air should lift the chaff on the sieve while the shaking action conveys the material rearward. Canola seeds are light and are easily blown out the back of the combine if the airflow rate is too high.
On the other hand, the material does need to be lifted slightly by air to improve separation, so provide just enough wind to maintain a "live" sieve. Start with a low fan speed and gradually increase it until good separation occurs with no canola being blown over the chaffer. If canola is lost out the rear of the combine with the fan and chaffer opening balanced, control motor speed and ground speed to reduce grain losses. Generally, it's better to control air volume by manipulating fan speed than by adjusting chaffer vanes.

Machine Adjustments in the Field
Field conditions change hourly, usually changing combine performance. Frequent checks and readjustments may be necessary in the field if harvest losses are to be held to acceptable levels. Inspection of the canola in the grain tank and a thorough search for loose seed on the ground behind the combine are necessary to know if machine adjustments are needed and, if so, where. If several adjustments are needed, evaluate each one individually rather than altogether.
The amount of trash in the harvested crop can be reduced by increasing fan speed, closing the bottom adjustable sieve, and/or opening the concave slightly. Check for leaky grain points from auger housings or pans. Use duct tape or caulking to seal loose or rusty conveyor housings.
A combination of adjustments may need to be made to avoid overloading the lower sieve. If returns are too high, try the following adjustments in order: 1) close the chaffer, 2) open the shoe, 3) reduce fan speed and 4) reduce the cylinder/rotor speed or ground speed.

Harvest Losses
Any harvest method involves some seed loss. Much of the work related to field and machine losses has identified seed losses with harvest method and report the following:

Swathing machine losses + shatter in the swath + combine losses both from the header and in separation.

Direct Combining
Shatter losses prior to harvest + combine losses

A British report reveals that common seed loss rates for rapeseed are between 25 and 50 pounds per acre for either method. If measuring harvest losses, this corresponds to a seed count of 65 to 130 seeds per square foot behind the combine. A grain loss monitor can aid in the detection of separation losses. Unacceptably high losses (as much as 50%) are possible when combines are incorrectly adjusted or not operated to match field conditions.

Storage and Drying
Safe Storage Periods for Canola
The storability of canola depends primarily on seed moisture content, temperature and soundness. One author summarized several studies on the safe storage times for canola as given in Table 7-A.

Table 7-A. -- Safe Storage Limits of Canola as Affected by Moisture Content and Temperatures When Aerated Intermittently.
Temperatures of the Grain, oF
% 50 60 70 80 90
18 1 W 4 D 1 D -- --
16 3 W 10 D 4 D 2 D --
14 2 M 3 W 12 D 5 D 2 D
12 5 M 2 M 1 M 2 W 6 D
10 10 M 4 M 2 M 3 W 10 D
9 20 M 9 M 4 M 6 W 3 W
8 40 M 18 M 7 M 3 M 5 W
D=Days; W=Weeks; M=Months

High moisture canola (above 12%) has extremely short storage periods, especially when held at normal springtime temperatures (above 70oF). For example, canola held at 14 percent moisture and 70oF may heat and spoil within two weeks, but if it is dried to nine percent, it should keep in good condition for four months. These time estimates illustrate the relative effect of temperature and moisture. They cannot be considered as precise predictions of storage time because other variables and localized bin conditions also influence storability.
The basic equilibrium relationships for canola have been developed to identify safe storage moisture levels as seasonal temperatures vary. These results are shown in Figure 7-1 and Table 7-B over a normal range of storage conditions. Their implications for storage recommendations for Kentucky are combined with other grains and shown in Table 7-C.

Table 7-B. -- Equilibrium Moisture Contents (%wb) for Canola at Various Temperatures and Relative Humidities.
Relative Humidity, %
oF 10 20 30 40 50 60 70 80 90
35 3.0 4.5 5.9 7.1 8.4 9.7 11.2 13.1 15.9
41 2.7 4.3 5.6 6.8 8.0 9.3 10.8 12.7 15.4
50 2.4 3.9 5.2 6.4 7.6 8.8 10.3 12.1 14.8
59 2.1 3.6 4.8 6.0 7.2 8.4 9.8 11.6 14.2
68 1.8 3.3 4.5 5.6 6.8 8.0 9.4 11.2 13.8
77 1.6 3.0 4.2 5.3 6.5 7.7 9.0 10.8 13.3
86 1.4 2.8 4.0 5.1 6.2 7.4 8.7 10.4 12.9
95 1.2 2.6 3.7 4.8 5.9 7.1 8.4 10.1 12.6
104  1.0 2.4 3.5 4.6 5.6 6.8 8.1 9.8 12.2
Source: Transactions of the American Society of Agricultural Engineers.

Table 7-C. -- Recommended Temperatures and Moisture Contents for Grain Storage in Kentucky.
Month of Storage Average Monthly
Temp. Owensboro,
Ky oF
Grain Temp. oF
Maximum Allowable Recommended Moisture Content, % wb
Min. Max. Corn Soybeans Wheat Sorghum Canola
Jan. 34.9 35 45 15.7 14.3 14.2 14.3 10.7
Feb. 37.9 35 45 15.5 14.0 14.1 14.2 10.5
Mar. 46.0 41 51 14.9 13.7 13.7 14.1 9.9
Apr. 57.9 53 63 14.3 12.2 13.3 13.8 9.2
May 66.8 55 65 13.8 11.6 13.1 13.7 8.8
June 75.3 55 65 13.3 11.1 12.8 13.5 8.4
July 78.2 55 65 13.2 10.9 12.7 13.4 8.3
Aug. 76.8 55 65 13.3 11.0 12.8 13.5 8.3
Sept. 70.2 55 65 13.6 11.4 13.0 13.6 8.6
Oct. 59.5 55 65 14.2 12.1 13.3 13.8 9.1
Nov. 46.6 42 52 14.9 13.2 13.7 14.1 9.9
Dec. 37.3 35 45 15.5 14.0 14.1 14.2 10.6

Keep Humidity Below 65 Percent
Grain stores well if it is kept dry, cool and clean. This prevents spoilage due to heat produced from activity by insects, molds and mites. The best storage conditions are provided by drying canola to a safe level (8-9%), aerating the grain after drying to control the temperature to within 10 to 15oF of the average monthly air temperature and cleaning the canola to remove excessive levels of trash and fines. By keeping the grain moisture within eight to nine percent the humidity in the void spaces is below 65 percent, which is dry enough to prevent mold growth.
Canola seeds are very small (0.05- to 0.09-inch diameter, depending on variety) and create a high resistance to airflow. From a practical sense this mandates low grain depths, otherwise higher power requirements are needed for drying and aeration fans. Also wire or plastic window screen is often used to cover storage bin floors, aeration ducts and the inside of drying columns in high speed dryers to prevent the tiny seed from lodging in perforations and blocking airflow.
The bulk density of stored canola depends on the variety and the method of filling the bin. One study revealed the range to vary from 52.6 pounds per bushel (lb/bu) for a large seed variety filled without a grain spreader to 60 lb/bu for a small seed variety filled with a spreader. Both varieties were evaluated at low moisture levels (below 7%).
For any storage temperature, canola must be dried to a much lower moisture content than other grains. Fortunately, canola is often harvested at a moisture level very near the recommended storage condition so little drying is actually required. The moisture contents given in Table 7-C should not be exceeded for best protection against storage pests in Kentucky.
As with wheat, successful storage through the summer is difficult because storage temperatures are usually higher than desirable, especially along bin walls with full exposure to the sun. Even though grain temperatures along bin walls cool during the night, the overall effect of repeated exposure results in a temperature imbalance within the bin which can lead to moisture migration. Unless the grain is aerated at night or during moderate weather (T << 65oF) spoilage can result. Since cool temperatures are usually not available in Kentucky until mid-September, moisture content is the primary factor that influences storability. Unless a producer has prior experience with holding wheat or other grains through the summer, the best option may be to let the grain elevator or processor store the crop. This places the risks associated with grain storage in the hands of operators who have more experience with canola.

Storage Structures
Canola stores best when held in weather-tight, rodent-proof structures. Round metal bins are the best choice assuming all leaks are sealed and access by mice, rats and birds is eliminated. Bins without perforated floors should be sealed along the foundation ring to prevent moisture uptake by the grain on the floor.
Experienced canola growers indicate that fines have a tendency to accumulate in a ring three to four feet from the center of round bins instead of near the center as with corn or soybeans. Standard grain spreaders have not been especially helpful in uniformly distributing these fines. It is especially important to level the grain surface after binning canola. This helps eliminate heat build-up in the peak and aids in uniform airflow through the top surface.
Temperature monitoring equipment is recommended in bins, silos and flat storage structures to check the condition of canola during storage. Temperatures should be checked frequently (every 2 days) after initial binning and aeration to be sure conditions have stabilized. Observations may be less frequent (every 1-2 weeks) after the canola has been cooled or turned (moved to another storage bin).
If monitoring equipment or temperature cables are not available, core the bin within a few days after storage and check for signs of heating and spoilage. Storage managers report that canola has a distinctive odor when it is going out of condition. If unusual odors are detected, the canola should be aerated or turned immediately and sampled thoroughly to determine the extent of damage.

Handling and Cleaning
Most common handling equipment can be used for loading and unloading canola into or out of trucks, wagons and bins. Remember that the diameter of a canola seed ranges from 3/64- to 3/32-inch, so the slightest cracks in boots, drop boxes and enclosures of transporting equipment must be sealed with duct tape or caulk.
Operate augers at full capacity and moderate speeds to avoid excessive damage to the seed. Conveyor belts should be used where available provided steep inclines are avoided and discharge chutes are positioned directly over the belt to lay the seed in the direction of flow. Drag conveyors have been used successfully but experience with canola suggests that the spacing between paddles should be reduced to maintain satisfactory capacity. Pneumatic conveyors can handle canola adequately but may have difficulty in feeding and discharging the seed. Kernel damage is usually not a problem for most equipment unless the moisture content is below seven percent.
All canola lots contain certain levels of fines or trash and chaff. The fines are comprised of broken canola seeds, weed seeds and soil particles which would pass through a number 21 sieve (0.0321-inch opening). The chaff mainly consists of weed seeds and broken pods and stems.
Uneven distribution of trash and fines in a drier or storage bin causes uneven airflow through the grain. Concentrated pockets of fines create higher resistance to airflow than clean canola and reduce the drying or cooling rate. Conversely, pockets of trash or chaff offer less resistance to airflow than clean canola and, therefore, dry or cool more quickly. In extreme cases, high concentrations of fines can totally block airflow altogether and render aeration virtually ineffective as a grain conditioning tool. In these cases, turning the grain may be the only alternative to control the development of hot spots or spoilage.
Mechanical cleaners generally work better than pneumatic cleaners for canola, but the cleaning capacity may be five to 10 percent lower than for other grains. Since most of the trash is larger than canola kernels, screens and scalpers work well. Cleanings should be burned or spread back in the field so as not to provide a good harborage for insects near the storage bins.

Insects, Molds and Mites
Mites are one storage pest some producers of other grains may not be familiar with. They typically feed on the soft inner seed, leaving a hollow seed coat. This seriously lowers test weight, quality and value. Heavy infestations may leave a distinct odor in canola. Mites favor canola that is above eight percent moisture. They can develop from an egg to an adult in about 14 days at temperatures above 68oF, but it takes a few months if the temperature is 40oF.
Good bin sanitation can prevent mite and insect infestations altogether. Before placing grain in the bin, thoroughly sweep walls and floors to remove broken grain and dust. Spray both sides of all bin surfaces with a grain protectant. Remove the dust and fines that accumulate under aeration ducts and plenum areas, if possible. Clean handling equipment as well and uniformly dry canola to eight percent moisture to avoid problems associated with storage pests.
Trash and foreign material have different equilibrium properties than canola seeds, so mold growth may develop within large pockets of stalks or pods even though the bulk of canola in a bin is dry enough for safe storage. Some insects feed on mold colonies so if they are allowed a foot-hold within a bin, other storage problems may develop and rapidly expand to cause significant grain spoilage.
The best way to avoid this potential profit robbing problem is to clean the canola prior to binning and to inspect it frequently (every 2 weeks) to detect any problems that may develop. If a problem area is identified early, corrective measures are usually sufficient to avoid extensive damage.
Few chemical control options are presently available for stored canola. The most cost effective management strategy is to follow proven equipment cleaning procedures prior to placing canola in the bin. Remember that no protectant may be sprayed directly on canola during filling or as a cap-out treatment. Resin-coated fly strips may be suspended in the head space of a bin or storage building to guard against moth activity. One strip treats 1,000 cubic feet of space and provides protection for two to three months. Funnel-shaped insect traps may be inserted just under the grain surface to monitor insect activity, but don't forget to remove them before unloading any grain.

Fans and Airflow
Canola has a resistance to airflow which is six to 10 times that of corn and two to three times the resistance of wheat or milo. Its airflow resistance generally lies between that of fescue and crimson clover. Consequently, airflow through canola is very restricted as compared to other grains. Expect even the best equipment to be severely limited in the amount of air that can be provided for canola drying and aeration.
Air delivery and efficiency of drying or aeration fans can best be enhanced by applying the following rules:
use large diameter bins,
keep grain depth shallow,
level the top surface, and
use centrifugal fans.

Bin drying fans should provide at least one cubic foot of airflow per minute (cfm) per bushel of undried grain. Aeration fans should provide at least 1/10 and preferably 1/4 cfm per bushel of grain to be cooled. Approximate airflow capabilities for common axial and centrifugal fans are shown as functions of grain depth. The upper limits of each region are based on static pressures (water column) of 2.5 inches for axial fans and 7.0 inches for centrifugal fans. Data for a small seed size variety of canola at 10% moisture content and sprinkle filled (tight pack) in the bin. (Original data from Jayas, 1987).Figure 7-2 illustrates how air delivery capability of axial and centrifugal fans is affected by canola depth in a bin. Most axial fans would not provide minimum drying airflow (1 cfm/bu) if grain was more than seven feet deep. At the same seven foot depth, a centrifugal fan could provide about two cfm per bushel. As a result, a centrifugal fan would reduce drying time for the seven foot depth by about 50 percent as compared to an axial fan.
Centrifugal fans could also provide the minimum airflow for drying at depths up to about 10 feet. Axial fans are generally adequate for aeration until canola depth exceeds 16 feet. All fans, axial or centrifugal, must have a total air delivery capability that is adequate for the total bushels of grain in the bin. An under-sized centrifugal fan should not be considered as an adequate replacement for a properly sized axial fan.

Fan Overload Potential
It is almost a certainty that the fans installed on most existing grain bins will operate in an overloaded condition when drying canola. When canola is deeper than about three feet for axial fans or six feet for centrifugal fans, total fan air delivery is reduced by more than 50 percent from normal expected output. Fortunately most fans can handle some overload without motor damage. At some point, however, the motor windings may overheat due either to excessive overload or to insufficient airflow for motor cooling. It is thus essential that canola drying fans have motors with built-in thermal overload protection. These thermal overloads automatically turn the motor off when it overheats and help prevent damage to the motor windings. When a fan motor does become overloaded there is little recourse but to reduce grain depth.

Aeration and Temperature Control
Canola should be cooled immediately after drying to reduce the storage temperature as much and as quickly as possible. Keep in mind that canola offers more resistance to airflow than fescue seed. Thus, cooling times are considerably slower for canola than with other grains at the same depth. If dry canola is placed directly in the bin from the field, run the fan for several days to remove field heat and to control heating by respiration. Stop the fan only after all the grain has been cooled. Check the grain below the surface a few days afterwards to be sure that no hot spots have developed. If hot spots are found, the fan should be operated regardless of the outside air conditions until these areas have cooled. In severe cases, the grain may have to be moved to another bin to disperse pockets of wet grain, trash or fines that can cause blockages to airflow.
A minimum rate of 0.1 cfm for each bushel (cfm/bu) is usually adequate for aeration provided that fines and trash are spread evenly throughout the bin. Compensate for the high resistance to airflow by reducing the depth to about one-half that for wheat or one-third that for corn. At the minimum airflow rate about 120 to 150 hours of continuous fan operation are required to force a cooling cycle completely through a bin of grain. If the rate is increased to 1/2 cfm/bu, cooling time should be between 24 and 30 hours.
Intermittent fan operation may be desirable at the larger air flow rate to take advantage of more favorable weather, but this requires a different type of fan and a much larger fan motor. For example, a 24-foot diameter bin with a 16-foot eave height (6 rings) that is level full with canola requires a 0.5 horsepower (hp) motor on an axial fan to provide 0.1 cfm/bu. In contrast, if the farmer wanted to supply 0.5 cfm/bu a three hp motor would be needed on a centrifugal fan.

Canola that is harvested above 10 percent moisture should be dried to nine percent or lower, depending on the anticipated storage period. Expect lower air flows in drying bins or high speed dryers because of the smaller seed. Thus lower drying air temperatures are recommended to avoid overheating the grain. If air blockage is coupled with excessive drying air temperatures in a high speed dryer, fires may result. Keep dryer temperatures below 150oF to avoid overheating problems. Cleaning the canola prior to drying also reduces the risk of fires. A maximum of 105oF should be used for seed canola since excess heat exposure lowers germination.

Natural Air and Low-Temperature Drying
Natural air and low-temperature drying (10oF above outside air) work well with canola provided adequate fan horsepower is available and the grain moisture is not above 10 percent. Because canola has about 10 times as many seeds per given volume than most other grains, it is extremely difficult to move air through a full drying bin (Figure 7-2). One way to compensate for the smaller seed is to limit grain height to one-third the depth normally used for drying corn. All drying bins should have a full perforated floor to overcome potential air distribution problems.
Stirring devices loosen the grain and enhance air movement through drying bins. Studies have shown a 10 to 20 percent increase in airflow with single or multiple screw units. Drying depths can generally be increased by about one foot when stirring augers are used.
Computer programs are available to help select a drying depth based on a particular bin and fan combination. Evaluations reveal that a drying bin fan should be at least five horsepower and capable of delivering one to three cfm per bushel of wet grain at four inches of static pressure. For a 24-foot diameter bin, the corresponding drying depth could be up to six feet for clean grain if a centrifugal fan is used with no stirring devices. Drying and aeration fans should be positioned to force air up through the grain (positive pressure).
Bin drying methods are relatively slow, consequently the fans should be started immediately after the floor is covered. Drying will occur as long as the relative humidity is below 70 percent (Table 7-B). Grain rewets much more slowly than it dries so it is usually better to keep the fan running even at night and during short periods of wet or rainy weather. Canola at 10 percent moisture is similar to wheat at 15 percent but heats rapidly if the fan is turned off. Only in cases of prolonged high humidity (several days > 80%) is it advantageous to operate the fan intermittently until the weather changes. When in doubt, keep the fan running to control grain temperatures.
Use low-temperature drying only if the relative humidity of the outside air is above 70 percent. Limit the temperature rise to a maximum of 10oF since higher temperatures overdry grain on the bottom of the bin and pump more moisture through the upper grain layers where it may condense on the grain or bin surfaces and cause spoilage.

High-Temperature Drying
High-temperature batch and continuous flow dryers work well for canola, but some adjustments are needed. First, check the screen size on column dryers, since most are equipped with a standard size of 0.09-inch (3/32). Since most canola seed varieties pass through or lodge in standard screens, smaller screens are mandatory. While manufacturers offer 0.04- to 0.07-inch screens for canola, some producers simply line the interior of their drying columns with window screen to avoid leakage problems without causing severe airflow restrictions. Check with the dryer manufacturer before making any changes to be sure that fan operation will not be adversely affected. It is also a good idea to inspect floors and unloading augers and seal all cracks and crevices to prevent leakage of the tiny seeds.
The maximum drying air temperature for canola should be 150oF (105oF for seed canola) with a moisture content of 10 to 17 percent. Expect drying capacities to be about half the rated capacity for corn. Drying canola from 15 percent moisture to 10 percent is similar to drying wheat from 19.5 percent to 14.5 percent in terms of capacity and drying times (Table 7-D). Fuel requirements are lower for canola than for wheat.

Table 7-D. -- Batch Dryer Performance for Canola, Corn and Wheat (with canola screen openings of 0.07 in)a.
Canola Corn Wheat
Drying Conditions
Air Temperatureb 150-170 220-270 180-230
Incoming Moisture 15 25.5 19.5
Final Moisture 10 15.5 14.5
Capacity (bu/hr)b 117-140 80-126 113-143
Batch Times (hour)
Filling 0.15-0.2 0.15-0.3 0.15-.25
Drying 0.95-2.0 1.00-2.2 0.85-1.7
Cooling 0.35-0.4 0.40-0.9 0.40-0.7
Unloading 0.15 0.15 0.15
Total 1.6-2.8 1.7-3.5 1.6-2.8
Fuel and Energy Consumed
Gallons LP/h 6.3-7.8 11.6-16.4 8.0-10.9
Gallons LP/100 bu 5.6-5.3 13.1-14.4 7.6-7.0
BTU/lb water removed 1650-1700 1500-1700 1700-1800
Fuel cost (cents/bu-pt)c 0.73-0.7 0.85-0.94 0.99-0.91
aPrairie Agricultural Machinery Institute Evaluation Report Nos. 307, 308, (1983) and 424 (1985).
bUnderlined numbers represent test conditions for recirculating batch dryers.
cFuel cost based on LP gas price of $.65/gallon.
NOTE: Maximum kernel temperatures should be 110, 140 and 130 for canola, corn, and wheat, respectively.

Table 7-E. -- Comparison of Continuous Flow Dryer Performance for Different Grains (with canola screen openings of 0.07 in)d.
Canola Corn Wheat
Drying Conditions
Air Temperature 145 220 190
Initial Moisture 15.0 25.5 19.5
Final Moisture 10.0 15.5 14.5
Capacity (bu/hr) 170 200 360
Fuel and Energy Consumption
Moisture Removed 5 10 5
Fuel consumption (gal/h) 10 30 25
Gal/100 bu 6.0 15 6.9
Energy consumption (BTU/# water) 1800 1700 1720
Fuel Cost (cents/bu-pt)e 0.78 0.98 0.90
dFrom Prairie Agricultural Machinery Report Nos. 289 and 290, 1982.
eBased on $.65/gal LP.

Alternate drying methods should be used for very wet crops (> 17% moisture content). One method is to run the canola through the dryer in more than one pass to avoid seed shrivelling or cracks and to maintain acceptable dryer performance. Reduce the drying air temperature by 10oF for every two percent increase in moisture above 17 percent. A maximum moisture removal of five points for each pass through the dryer is suggested. A second option is to use combination drying where canola is dried to 10 percent in a high-temperature dryer then transferred to a bin with a false floor where drying is completed with low-temperature drying, as described previously.

Canola Handbook. 1989. Central Soya/U.S. Canola Processors.
Canola Production Handbook. 1989. J.P. Harner and J.A. Kramer. Cooperative Extension Service, Kansas State University.
Jayas, D.S., S. Sokhansanj, and N.D.G. White. 1989. Bulk Density and Porosity of Two Canola Species. Transactions of the ASAE. 32(1):291-294.
Jayas, D.S., S. Sokhansanj, E.B. Moysey, and E.M. Barber. 1987. Airflow Resistance of Canola (Rapeseed). Transactions of the ASAE. 30(5):1484-1488.
Prairie Agricultural Machinery Institute. Evaluation Report No. 290. 1982. Superb S500C Grain Dryer. Humboldt, Saskatchewan, CN.
Prairie Agricultural Machinery Institute. Evaluation Report No. 307. 1983. Moridge 8440 Grain Dryer. Humboldt, Saskatchewan, CN.
Prairie Agricultural Machinery Institute. Evaluation Report No. 308. 1983. GT 380 Grain Dryer. Humboldt, Saskatchewan, CN.
Prairie Agricultural Machinery Institute. Evaluation Report No. 424. 1985. Superb AS600G Grain Dryer. Humboldt, Saskatchewan, CN.
Otten L., R.B. Brown, and K.F. Vogel. 1989. Thin-layer Drying of Canola. ASAE Paper No. 89-6100. Presented at the ASAE/CSAE Summer Mtg. Quebec, CN.
S. Sokhansanj, W. Zhijie, D.S. Jayas, and T. Kameoka. 1986. Equilibrium Relative Humidity-Moisture Content of Rapeseed (Canola) from 5oC to 15oC. Transactions of the ASAE. 29(3):837-839.
S. Sokhansanj. 1991. Management Schemes for Optimum Control of In-bin Drying of Canola. Progress report submitted to the Alberta Canola Producers Commision. Agricultural Engineering Department, University of Saskatchewan.
Succeeding with Canola. 1989. Allelix Crop Technologies Ltd.
Thomas, D.L., M.A. Breve, and P.L. Raymer. 1991. Influence of Timing and Method of Harvest on Rapeseed Yield. Journal of Production Agriculture. 4(2):266-272.
Ward, J.T., W.D. Basford, J.H. Hawkins, and J.M. Holliday. 1985. Oilseed Rape, pp 223-258. Farming Press LTD. Wharfedale Rd., Ipswich, Suffolk, England.

8. Marketing and Profitability Considerations
(Steven K. Riggins, Richard L. Trimble and W. Donald Shurley)
Kentucky's canola acreage expanded rapidly from its inception in 1986 through 1989 and has been fairly stable since. The rate of future expansion depends on canola's profitability in the farm operation relative to other enterprises. In turn, enterprise profitability hinges on the per unit cost of production and the price of the product. The per unit cost of production is contingent upon input costs and yield potential and variability. The price of canola is most strongly affected by the price of soybeans, by prices of other competing vegetable oils and by U.S. farm programs.

Joint Products
Like soybeans, canola is processed into two main products, canola meal and canola oil. In contrast to soybean pricing, it is most likely that the value of canola oil will be of much more importance in determining canola price than the value of the meal. Canola is roughly 40 percent oil and 60 percent meal when processed while soybeans yield about 20 percent oil and 80 percent meal. Further, soybean meal is a very high quality feed ingredient with relatively few substitutes whereas there are several vegetable and animal oils that can compete with canola oil for human consumption, its main usage. Therefore, canola prices should be most heavily influenced by the demand for canola oil relative to the demand for competing vegetable oils.
Canola's potential for expanded acreage in the United States is directly related to the very low level of saturated fat contained in refined canola oil. Canola contains significantly less saturated fat (6%) than any other edible oil. Safflower oil is listed at 9 percent, sunflower oil 11 percent, corn oil 13 percent, olive oil 14 percent, and soybean oil 15 percent while palm oil is 51 percent, lard is 41 percent and coconut oil is 92 percent saturated fat. Given all the concern over heart disease and high levels of cholesterol in the blood, it seems likely that proper advertising could provide added stimulus to the relative demand for canola oil visa vis other edible oils.
The value of canola meal should remain dominated by the price of soybean meal. Canola meal is only 37 percent protein compared to 44 percent for soybean meal. There is also some evidence that the percentage of canola meal in livestock feed rations must be limited to avoid some feeding problems, particularly with single stomached animals. However, some poultry producers claim that a limited quantity of canola meal in feed rations produces a desirable color in chicken breast meat. This might provide some slight improvement in canola meal prices visa vis other protein feeds in the Southeast poultry belt, but it is unlikely to have any measurable effect on the overall canola price.

Price Relative to Soybeans
Insufficient data exist at this time to accurately predict the relationship of canola prices in Kentucky to local soybean prices. Some market analysts claim that Kentucky canola producers have received roughly 80 percent of the local soybean price.
The major difficulty in predicting a canola-soybean price relationship is because of the rapid changes occurring in the market. The 1989 harvest was the first one that did not have to be shipped to Canada for processing. The opening of two new processors that year, one in Tennessee and one in Georgia, had to affect basis price relationships for canola. Current information indicates that the processing plant in Tennessee is being closed this summer due to lack of volume. However, the plant in Georgia now has a buying station in Kentucky and seems to be committed to the canola industry of the region.
The number of local elevators willing to buy canola expanded significantly in 1989. The grading system, however, is still in a state of flux. The U.S. Department of Agriculture (USDA) established a set of grades and standards for canola in the summer of 1991. Some buyers indicate that garlic is still a significant factor that farmers must learn to control or risk receiving substantial dockage upon sale.
Further basis changes should be expected as production stabilizes and the marketing system matures.

Government Program Impacts
The 1990 Farm Bill and its focus on planting flexibility and market-driven plantings should be favorable to expanding canola acreage. Rules, were only recently modified to allow the double-cropping of canola and soybeans under the 0-92 provisions of the new law. Initial analysis indicates that such a combination would most likely be a very strong incentive for Kentucky grain producers to plant canola.
As indicated in the following section on canola profitability, the crop appears to have a place in Kentucky agriculture. For the 1991 crop year, farmers were allowed to plant up to 25 percent of their corn and wheat base to canola or to canola double-crop soybeans. Given the relatively high target prices for corn and wheat, it is likely that many farmers will not be willing to plant canola on the 10 percent of base acres that are referred to as optional flex acres. However, the 15 percent known as normal flex acres receive no deficiency payments. Therefore, many farmers may give canola a try on a limited basis.
Another possibility for canola or canola and double-crop soybean production is known as zero certification, a new possibility under the latest Farm Bill. Farmers have to certify that no program crops are going to be produced and, therefore, they give up deficiency payments. This probably will cause most farmers to ignore the zero certification option.
The new law also established a marketing loan for canola at 8.9 cents per pound with a two percent loan fee for an effective marketing loan rate of 8.72 cents per pound or $4.36 per bushel. This compares to a target price of $4.00 for wheat. Both canola and wheat have similar yields and production costs, therefore, the marketing loan provides canola with a revenue potential essentially the same or better than wheat. Yield in any given year could cause one or the other of the two crops to provide the greatest return.

Pricing Canola
Apparently most canola sold in Kentucky over the past few seasons was sold on a cash basis around harvest time. However, it should be possible to forward contract canola as buyers can hedge it either through the Winnipeg Futures Exchange or cross hedge it with soybeans on the Chicago Exchange. For those with knowledge of hedging grains, it may be advisable to do your own hedging or cross hedging directly. However, lack of historical basis data may make the risk of hedging too large to bear.

Profitability of Canola
In deciding to bring canola into an existing farm operation as a possible new enterprise, several factors must be considered. First of all, is canola profitable compared to alternative crops? Second, what risks are involved and how should these be weighed against any potential profits? Lastly, where and how does canola fit into the current farm operation and cropping system?
Canola production practices and machinery and equipment used are similar to winter wheat. An enterprise budget for canola was developed assuming these similarities and based on University of Kentucky recommended seeding and fertilizer rates and production practices (Table 8-A).

Table 8-A. -- Estimated Canola Enterprise Costs and Returns for 1990, Conventional Tillage, Drilled.
Amount Unit Price Total
Gross Returns Per Acre
Canola 2000 lbs 0.10 200.00
Variable Costs Per Acre
Seed 6 lbs 2.55 15.30
Fertilizer 1 acre 41.53 41.53
Lime 1 ton 9.00 9.00
Herbicides 1 acre 0.00 0.00
Insecticides 1 acre 0.00 0.00
Fungicides 1 acre 16.00 16.00
Fuel and Oil 1.4 hrs 4.67 6.54
Repairs 1 acre 10.00 10.00
Custom Hire 1 acre 3.25 3.25
Equipment Rental 1 acre 0.55 0.55
Drying 2000 lbs 0.00 0.00
Crop Insurance 1 acre 0.00 0.00
Cash Land Rent 1 acre 0.00 0.00
Hired Labor 0 hrs 0.00 0.00
Interest 102.17 dollars 0.06 6.13
Total Variable Cost 108.30
Return Above Variable Cost 91.70
Budgeted Fixed Costs Per Acre
Depreciation 24.00
Taxes and Insurance 8.00
Total Budgeted Fixed Cost 32.00
Return to Operator Labor, Land, Capital, and MGT 59.70
Less Operator Labor 2.8 hrs 7.00 19.60
Return to Land, Capital, and Management 40.10
University of Kentucky, College of Agriculture, Cooperative Extension Service.

Several factors can affect production costs and individual producer costs will likely vary from those shown. The budget, for example, assumes no use of herbicides or insecticides, but does reflect the use of a fungicide. Also, depending on availability and geographic location of markets, hauling expenses could contribute to fuel or custom charges significantly higher than those shown.
In recent years, Kentucky farmers have reportedly received prices ranging mostly from 8 to 14 cents per pound ($4 to $7/bu -- 50 lb/bu). Canola yields have ranged mostly from 25 to 60 bushels (1,250 to 3,000 lb) per acre.
Our budget assumes a typical or supposedly average yield of 2,000 pounds (40 bu/acre) and an expected price of 10 cents per pound ($5.00/bu). Table 8-B shows the per acre Return Above Operating Costs (RAOC) at various prices and yields.

Table 8-B. -- Canola per Acre Return Above Operating Costs, Various Prices and Yields*.
Yield Per Acre
1250 1500 1750 2000 2250 2500 2750
0.08 -8.30 11.70 31.70 51.70 71.70 91.70 111.70
0.09 4.20 26.70 49.20 71.70 94.20 116.70 139.20
0.10 16.70 41.70 66.70 91.70 116.70 141.70 166.70
0.11 29.20 56.70 84.20 111.70 139.20 166.70 194.20
0.12 41.70 71.70 101.70 131.70 161.70 191.70 221.70
*Returns are estimated funds available for operator and unpaid labor, debt payments, and overhead. Assumes Variable Costs are "sunk" and varying returns are due to weather, markets, and production risks.

In the short run or when making annual crop planning decisions, it is typically assumed that, among other factors, farmers make acreage decisions on the basis of which crops bring the highest RAOC.
It is expected that most producers would consider canola as an alternative to wheat in a wheat/soybean double-crop system. Based on 1990 costs, prices and government program payments where applicable, and at expected average or typical yield, canola appears competitive with other enterprises most often found on crop farms (Table 8-C). Comparing the RAOC, canola is competitive with wheat and canola/soybeans double-crop is competitive with wheat/soybeans, corn and full-season soybeans.

Table 8-C. -- Comparison of Estimated Net Returns for Canola and Other Crops at Typical Average Yields and 1990 Costs and Average Prices.
Corn* Soybeans Wheat* Canola Wht/SB* Can/SB
Yield/Acre 110 36 45 2000 45/28 2000/28
Price/(Bu or Lb) 2.75 6.10 3.00 0.10 3.00/6.10 .10/6.10
Crop Income/Acre 234.44 219.60 94.50 200.00 214.06 370.80
Flex Acres Income 19.21 19.21 19.21
Govt Payments/Acre 48.02 0.00 52.36 0.00 52.36 0.00
Total Income/Acre 301.66 219.60 166.07 200.00 285.63 370.80
Operating Costs/Acre 112.81 91.55 57.94 108.30 113.53 193.49
RAOC/Acre 188.86 128.05 108.13 91.70 172.10 177.31
Fixed Costs/Acre 39.65 38.60 32.00 32.00 39.65 39.65
Net Return/Acre** 149.21 89.45 76.13 59.70 132.45 137.66
*Crop Income and Operating Costs per Acre assume that only 77.5% of corn and 70% of wheat are grown to comply with government program acreage restrictions. The 15% Normal Flex Acres for both corn and wheat were assumed planted to full season soybeans and the Flex Acres Income reflects this crop's RAOC/Acre. Government payments based on 1991 USDA estimates of deficiency payments and program yields at 85% of 5 year state average crop yields.
**Net Return is the expected return to Land, Capital, Management, and Operator Labor.

Break-even analysis can be used to determine how price and yield changes or producer situations different from those budgeted can affect the relative profitability of alternative crop enterprise decisions. Figures 8-1 through 8-5 show the break-even canola yield needed to give the same RAOC as wheat given various wheat prices and yields and various canola prices. Assuming soybean yields and costs would be the same regardless of the decision to plant wheat or canola, these factors make analysis of the double-cropping alternatives of little importance.
Figure 8-1, for example, illustrates that if canola price is expected to be 8 cents per pound and if a producer expects to get 45 bushels of wheat and a price of $3.25 per bushel, canola yield would have to be 2,150 pounds per acre to give the producer the same profit (RAOC) as wheat.
Figure 8-2, Figure 8-3, Figure 8-4, and Figure 8-5.

Alternatively, if canola price is expected to be 10 cents per pound, wheat price $3.25 per bushel and wheat yield 40 bushels per acre, the break-even canola yield would be only about 1,550 pounds (31 bu) per acre.
These break-even charts were prepared without considering government program payments for wheat. This means that given the presently high target price for wheat and the resulting deficiency payments available to qualifying producers, the break-even charts shown do underestimate somewhat the break-even canola yield needed to compete with wheat.
To provide further insight from a different perspective, Table 8-D shows the break-even canola price needed at various wheat prices and yields given an expected wheat yield of 45 bushels per acre. If wheat price is expected to be $4.00 per bushel and canola yield expected to be 2,000 pounds per acre, the break-even canola price would be 10.28 cents per pound or $5.14 per bushel.

Table 8-D. -- Break-Even Canola Prices at Various Canola Yields and Wheat Prices (Wheat Yield at 45 Bushels Per Acre).
Canola Yield Pounds/Acre
1250 1500 1750 2000 2250 2500 2750
Canola B/E Price (Cents per Pound)
2.50 11.04 9.20 7.89 6.90 6.13 5.52 5.02
2.75 11.94 9.95 8.53 7.46 6.63 5.97 5.43
3.00 12.84 10.70 9.17 8.03 7.13 6.42 5.84
3.25 13.74 11.45 9.82 8.59 7.63 6.87 6.25
3.50 14.64 12.20 10.46 9.15 8.13 7.32 6.66
3.75 15.54 12.95 11.10 9.71 8.63 7.77 7.06
4.00 16.44 13.70 11.74 10.28 9.13 8.22 7.47

Where Does Canola Fit?
Farmers appraising the merits of canola must consider their own situation in determining where canola fits within their operation.
For farmers producing wheat on land without a wheat base and thus not participating in the government program, canola as well as canola in a double-crop system with soybeans certainly appears competitive with wheat and wheat/soybeans under certain price and yield scenarios. Given recent changes that allow canola and double-crop soybeans to be grown on 0-92 base acres, canola looks particularly promising.
Canola is presently considered a non-program crop as is soybeans. Canola/soybean double-crop also appears to be a competitive alternative to corn. For producers participating in the corn program, the 1990 rules allowed crops such as soybeans or canola to be grown on corn acres without fear of base reduction as long as they were planted on flex acres.
Canola/soybeans also appears to offer a decided competitive advantage to full-season soybeans -- which would not interfere with participation in the corn and wheat government programs on non-base acreage.

It is impossible to state that all farmers in Kentucky should have canola in their farming operation. The market situation for the crop is in a rapid state of change that will surely affect local basis levels and pricing mechanisms. In addition, there is not yet sufficient data to provide a realistic assessment of the yield risk involved in producing canola. However, the limited experience in Kentucky certainly indicates that canola production has the potential to become a part of many farmers' crop rotation. This crop deserves serious consideration.

9. Canola as a Feedstuff for Animal Use
(Gary Parker)
In the past, the use of rapeseed as a source of edible oil for humans and protein-rich meal for livestock was limited due to high levels of glucosinolate and erucic acid. Feeding experiments have shown that intact glucosinolates are not particularly harmful; it's their hydrolytic products (isothiocyanates, oxazolidinethiones and nitrites) that cause problems. These products have a thyrotoxic activity which causes thyroid enlargement and growth depression. Ruminants are less susceptible to glucosinolates than non-ruminants. This is probably associated with degradation of the toxic products by microflora in the rumen.
As well as being a problem in the meal, these hydrolytic products are oil and solvent soluble. Their presence in the oil interferes with subsequent hydrogenation of the oil for margarine and shortening production.
In the past decade, Canadian plant scientists have developed a new cultivar of rapeseed low in erucic acid and glucosinolates and the term "canola" (double-low) is used to designate these low glucosinolate and erucic acid varieties from other cultivars of rapeseed. The oil and meal derived from the canola cultivars are nutritionally superior to oil and meal produced from rapeseed cultivars.

Soybean meal is the economical standard for protein supplementation in most livestock diets in the U.S. The value of alternative protein sources is determined by animal performance studies in which soybean meal is replaced by these alternative sources in the diet. Data collected from these research trials can then be used to develop a formula for economic worth based on differences in performance at various levels of replacement for soybean meal. Canola meal must be economically competitive with soybean meal on an equal available protein basis to be a major protein source in animal diets in the U.S.

Canola Meal
Values of various nutrient concentrations in canola meal and soybean meal are given in Table 9-A.

Table 9-A. -- Comparison of Nutrient Values (as fed) in Canola Meal and Soybean Meala.
Nutrient Canola Meal Soybean Meal
Dry Matter, % 93.00 90.00
Crude Protein, % 37.50 44.00
Crude Fat, % 3.40 0.80
Crude Fiber, % 11.40 6.50
ME, kcal/lb 1227.00 1409.00
Ash, % 6.80 5.80
Calcium, % 0.68 0.25
Phosphorus, % 1.17 0.60
Amino Acids
Lysine, % 2.21 2.90
Tryptophan 0.44 0.64
Threonine 1.68 1.70
Methionine 0.76 0.52
Cystine 0.90 --
Arginine 2.26 3.20
Histidine 1.04 1.12
Isoleucine 1.28 2.0
Leucine 2.57 3.37
Phenylalanine 1.45 2.10
Valine 1.64 2.02
aNutrient values taken from: Fonnesbeck et al. (1984), NRC (1988) and Feeding with Canola Meal, 1986, Canola Council of Canada.

Canola meal is lower in crude protein (37.5 vs 44.0%) and metabolizable energy (1227 vs 1409 kcal/lb). It is also higher in fiber (11.4 vs 6.5%) compared to 44 percent soybean meal, which can affect feed intake and palatability when fed at a high level, especially to swine and poultry. The amino acid composition of canola meal compares favorably with soybean meal. However, soybean meal has a slightly higher level of lysine (2.90 vs 2.21%) and canola meal is higher in methionine (0.75 vs 0.52%). As a result, when these two protein sources are used together their amino acid profile tends to complement each other. Canola meal has a higher phosphorus value than soybean meal but like soybean meal, the phosphorus is not well utilized by monogastrics. The fat content of canola meal tends to be higher than soybean meal (3.4 vs 0.8%), because the gums (from oil extraction process) are added back at about the 1.5 percent level. However, the energy level of canola meal is reduced due to its higher fiber content.

Full-Fat Canola Seed
Under most conditions, economics would dictate that canola seed be processed to remove the oil for human consumption. However, due to price discounts for poor quality canola seed or transportation costs associated with delivery to distant processing plants, the use of these seeds in livestock diets may be justified. Values of various nutrient concentrations in whole canola seed and whole soybeans are presented in Table 9-B.

Table 9-B. -- Nutrient Composition of Full-Fat Canola and Soybean Seeda.
Nutrient Full-Fat Canola Full-Fat Soybean
Dry Matter, % 93.20 90.00
Crude Protein, % 24.90 36.70
Crude fat, % 37.60 18.80
Crude fiber, % 8.60 5.20
ME, kcal/lbb 2040.00 1648.00
Ash, % 4.40 5.70
Calcium, % 0.45 0.26
Phosphorus, % 0.76 0.61
Amino acids
Lysine, % 1.94 2.25
Tryptophan, % 0.53 0.54
Threonine, % 1.35 1.42
Methionine, % 0.82 0.46
Arginine, % 1.94 2.54
Histidine, % 0.92 0.87
Isoleucine, % 1.11 1.60
Leucine, % 2.09 2.64
Phenylalanine, % 1.66 1.80
Valine, % 1.46 1.62
aNutrient values taken from: Fonnesbeck et al (1984), NRC (1988) and Feeding with Canola Meal, 1984, Canola Council of Canada.
bEstimated value (Fonnesbeck et al., 1984).

When canola seeds are added to a diet, they should be incorporated on an amino acid and energy basis rather than replace a protein source on a pound-for-pound basis.

Canola Use in Swine Diets
Canola meal can be used in the diet of all classes of swine. Most studies that involve the use of canola meal have been conducted in Canada where the diets are based on barley and wheat. Limited research has been conducted in the U.S. with canola meal and corn-based diets. It appears that the nutritional suitability of canola meal in corn diets may be slightly less than expected when compared to diets based on barley and wheat. This may be due to the better amino acid profile in these grains, especially for lysine, compared to corn. More definitive studies will be required to get a better understanding of the nutritional quality of canola meal for use in swine diets in the U.S.

Starting Pigs (weaning to 40 pounds)
In general, it appears that growth rate, feed intake and feed efficiency are reduced in proportion to the amount of canola meal present in the diet. From studies done in Canada, the Canadian Canola Council's current recommended level of inclusion for canola meal in weanling pig diets is eight percent. However, a more conservative inclusion rate of five percent in the United States with a corn based diet would probably be appropriate. With levels higher than 10 percent, there appears to be a reduction in feed intake. Taste preference trials conducted at the University of Alberta have shown that weanling pigs given a choice between canola or soybean meal would consume significantly greater quantities of a diet containing soybean meal. These experiments also demonstrated that pigs can detect the presence of canola meal at dietary inclusion levels as low as five percent. Therefore, an acceptable range of use for canola meal in starting swine diets would be five to eight percent of the total diet.

Growing Pigs (40 to 120 pounds)
A series of experiments conducted at the University of Alberta (1985) have shown that as canola meal replaces a greater percentage of soybean meal in the diet, growth rate, feed intake and feed conversion are reduced. Similar results were obtained in a study conducted at Michigan State University (1987) when feeding different levels of canola meal in corn-based diets, except that feed intake increased as more canola meal was added to the diet. Therefore, feed efficiency in the Michigan State trials was linearly depressed as the level of canola meal in the diet was increased from zero to 24 percent.
Most Canadian research would support an inclusion rate of up to 12 percent canola meal in growing pig diets. However, using data from trials conducted in the U.S. and considering the grain composition differences, a more conservative estimate would be eight to 10 percent canola meal in swine diets. At these levels, average daily gain and feed to gain should be reduced by only five to eight percent.

Finishing Pigs (120 pounds to market)
In reviewing the research conducted for finishing swine, canola meal can satisfactorily provide all of the supplemental protein (about 12% of total diet) in wheat- and barley-based diets without significantly reducing feed intake, growth rate, feed conversion or carcass quality. In corn diets, complete substitution of soybean meal with canola meal has produced normal gains although some research has shown a slight reduction in gain and feed efficiency. In the finishing phase, pigs appear to compensate for possible nutritional deficiencies in canola meal by increasing their feed intake. In so doing, overall performance of these animals and subsequent carcass measurements may be the same as control pigs (all soybean meal) at the expense of feed efficiency.

Breeding Swine
Canola meal appears to be a satisfactory supplemental protein source in both gestating and lactating sow diets, as summarized from available Canadian and English research. These studies evaluated the use of canola meal as the primary or sole source of supplemental protein (12% of total diet) and have shown no significant difference in reproductive performance over two parities compared to sows fed diets containing soybean meal. Again, U.S. data utilizing corn based diets is limiting and a conservative estimate of substitution might be eight to 10 percent of the total diet until further studies substantiate higher levels.

Full-Fat Canola Seed in Swine Diets
Very few research trials have been conducted to evaluate the use of full-fat canola seed in swine diets. Under most conditions, economics dictate that canola seed be processed to remove oil which is used for human consumption. Utilizing whole canola seed in swine diets could have an advantage due to the high fat content (38-40%) in canola seed. Research has shown significant advantages for feed efficiency and growth rate (primarily in warm weather) in pigs fed diets containing added fat. Also, the need to reduce sow weight loss during lactation in order to maximize milk production and subsequent reproductive performance has led to the recommendation that fat be included in lactating diets (major benefit in warm weather). Therefore, whole off-grade canola seed could be used effectively to increase the energy level in growing/finishing pig and lactating sow diets.
The canola seed contains approximately 24.9 percent protein, 37.6 percent fat, 8.6 percent fiber and 1.9 percent lysine. The seed does not contain the trypsin inhibitors that occur in soybeans, so it does not require heat treatment to make it acceptable as a feed ingredient for swine. In most experiments, small numbers of animals have been involved making specific conclusions difficult. Canadian trials have compared growing/finishing diets of wheat/barley/soybean meal with added fat to wheat/barley/whole canola seed. Their results would indicate that a level up to 15 percent inclusion rate of whole canola seed provided acceptable performance. Research at the University of Kentucky showed that inclusions above 10 percent raw canola seed in growing/finishing diets (keeping lysine constant) reduced gains and feed intake compared in a control corn/soybean meal diet.
These inconsistent results make it difficult to develop good feeding recommendations for raw canola seed. Some of the inconsistency may be due to experimental numbers and grain source differences. If raw canola must be used in corn-based swine diets, a conservative estimate of no more than 10 percent should be added to maintain normal animal performance. Raw canola seed must be ground to improve energy and protein utilization. The seeds grind very nicely when combined with the grain source to be used in the diet. But, in attempts by themselves the results have not been satisfactory.

Canola meal can be used in diets for all classes of swine but some reduction in weight gain and feed conversion may be experienced in starter and grower pigs. Reduced weight gain appears to be a result of reduced energy digestibility, amino acid availability and possibly remaining goitrogenicity in canola meal.
When all factors are considered (nutrient content, nutrient availability and performance), canola meal is considered to be equivalent, on an equal weight basis, to 70 percent of the value of soybean meal (44%) for starting and growing pigs and 75 percent the value of soybean meal for finishing and breeding swine. That is, when 44 percent soybean meal is selling for $200 per ton, canola meal priced at $150 per ton would be an equivalent buy for finishing and breeding swine.
Canola seed can be used as a source of energy and protein by growing/finishing pigs. Levels above 10 percent in a corn/soybean meal diet can potentially depress gain and feed intake. With limited data available on breeding swine it would be difficult to establish a useful level for inclusion in these diets at the present time.

Canola Use in Beef and Dairy Diets
Use in Calf Diets
Canadian research has shown that calves one to six months of age fed a diet containing canola meal had a higher percentage of red blood cells and glucose in the blood and a lower percentage of urea nitrogen compared to calves fed a diet containing soybean meal. Their results indicated a lower rumen degradability of canola meal compared to soybean meal when the two supplements were compared in isonitrogenous diets.
Recent studies done in the United States indicated that canola meal was equivalent to cottonseed and soybean meal as a protein supplement in calf starter diets. Average daily gain was equivalent for all diets with intake of the canola diet being less, resulting in a more profitable feed conversion in calves fed canola meal during the first four months of life.
Most research work would support up to 20 percent canola meal in starter calf diets.

Lactating Cows
Canadian trials have demonstrated that the incorporation of canola meal at levels from eight to 30 percent of the concentrate resulted in either no change or an increase in milk production when compared to soybean meal as the protein supplement.
Research conducted in the U.S. comparing canola meal with cottonseed and soybean meal has indicated that composition of milk did not differ among treatments and there was a tendency for higher milk yield from the cows fed diets containing canola meal. The total rumen volatile fatty acids were higher in cows fed the canola and soybean meal diets than in those fed the cottonseed meal diets.
Canola meal can be added to dairy cow grain/concentrate mixes up to the 25 percent level without effecting animal performance. Inclusion of canola meal in formulations should be based on its cost per unit of protein relative to other sources of protein. The higher level of fiber in canola meal can be an additional benefit when depressed milk fat content is a problem.

Beef Cattle Finishing Diets
While research trials with beef cattle involving the use of canola meal are limited, work done previously with dairy animals would strongly support a recommendation that canola meal can be the sole source of needed supplemental protein for these animals.
Recent work at Kansas State University compared canola meal with soybean meal for finishing steers. They observed no problems with acceptance of the canola meal diets. Feed efficiency was actually improved as the amount of canola meal increased in the diet with the 100 percent canola meal fed animals having the best feed to gain ratio. Their conclusions were that canola meal appears to have the potential to be an efficient and economical feed ingredient for beef cattle.
Some example recommendations by the Canadian Canola Council for uses of canola meal in beef cattle diets would be as follows:
Example 1: 700 pound growing steer on full feed corn silage would require 2 1/2 pounds of canola meal per day to meet the protein requirements for maintenance and daily gain of approximately two pounds.
Example 2: 1,000 pound finishing steer offered seven to 12 pounds of shelled corn plus 32 pounds of high quality corn silage would require 1 1/2 pounds of canola meal for maintenance and daily gain of three pounds.
They recommend that up to 20 percent of the grain/concentrate mixture can be comprised of canola meal for beef cattle.

Full-Fat Canola Seed
Whole canola seed which was not acceptable for processing due to inadequate growing conditions has been evaluated by several Canadian universities as a source of fat and protein for lactating cows. The canola seed needs to be cracked before inclusion in a concentrate mixture in order for the oil to be used effectively. The maximum suggested level of inclusion for whole seeds was six to 10 percent of the concentrate. Levels above this appeared to depress feed intake and milk yield.
While little research is available regarding full-fat canola seeds in beef cattle diets, it would be safe to assume that an acceptable range of use would fall into the six to 10 percent range.

Research data and Canadian experience would indicate that the use of canola meal in dairy and beef cattle diets as a source of protein is an acceptable practice. Its relatively high fiber content improves the feeding value when used to supplement corn silage or when included in complete feeds containing a high proportion of grain.
Experimental data would support the following levels of canola meal for the various classes of cattle: calves, 20 percent of the diet; dairy cows, 25 percent of the grain/concentrate mixture; and beef cattle, 20 percent of the grain/concentrate mixture.

Jim Herbek, Extension Grain Crops Specialist, Research and Education Center, Princeton, KY
Donald E. Hershman, Extension Plant Pathology Specialist, Research and Education Center, Princeton, KY
Douglas W. Johnson, Extension Entomology Specialist, Research and Education Center, Princeton, KY
James R. Martin, Extension Weed Control Specialist, Research and Education Center, Princeton, KY
Samuel G. McNeill, Extension Agricultural Engineering Specialist, Research and Education Center, Princeton, KY
Lloyd Murdock, Extension Soils Specialist, Research and Education Center, Princeton, KY
Douglas G. Overhults, Extension Agricultural Engineering Specialist, Research and Education Center, Princeton, KY
Gary Parker, Extension Swine Specialist, Research and Education Center, Princeton, KY
Steven K. Riggins, Extension Agricultural Economics Specialist, College of Agriculture, Lexington, KY
W. Donald Shurley, former Extension Agricultural Economics Specialist, College of Agriculture, Lexington, KY
Richard L. Trimble, Extension Agricultural Economics Specialist, Research and Education Center, Princeton, KY