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Kentucky Agricultural Experiment Station

2000 Research Annual Report

The Kentucky Agricultural Experiment Station encompasses all of the research activities of the College of Agriculture conducted on the Lexington campus, the Research and Education Center at Princeton, the Robinson Forest and Station in Eastern Kentucky, and our research farms in Central Kentucky. Our research faculty also conduct dozens of trials on farms and at other sites throughout the Commonwealth.

More than ever, the people and programs of the Experiment Station are focused on the issues which matter to Kentucky:

  • new economic opportunities for Kentucky communities;
  • survival of the family farm;
  • sustainable use of soil, water, and forest resources;
  • food safety and quality; and
  • employing new technology for the benefit of all Kentuckians.

This report portrays only a fraction of our continuing efforts to discover and develop the new ideas, technology, and unbiased information which are needed during these times of change and challenge in agriculture. A complete record of all 2000 Experiment Station projects and publications can be found on the College's Web site (; printed copies of the listing may be requested from:

Associate Director
Kentucky Agricultural Experiment Station
S-107 Agricultural Science Center
University of Kentucky
Lexington, Kentucky 40546-0091

2000 Experiment Station Highlights

  • More than $8.5 million in research grants in 2000, an increase of more than 40% since 1996.
  • Research faculty generated about $12 million in grants, contracts, gifts, and endowment income, meaning that more than one-third of the costs of the Kentucky Agricultural Experiment Station are self-generated.
  • Faculty published 282 original research articles and 70 books and book chapters during 2000.
  • The number of graduate students and post-doctoral scholars working in the College increased for the eighth straight year to 370.
  • The Beef Research Unit at the Woodford County Animal Research Center was completed. Numerous research projects are now underway at this world-class facility.
  • Construction began on the Plant Science Research Building. Completion and occupancy are expected in 2002.
  • M. Scott Smith was appointed the eighth Dean of the College of Agriculture and Director of the Kentucky Agricultural Experiment Station upon the retirement of C. Oran Little in December 2000.

Rx for Plants

Aphids are often considered the bane of crop producers. They can damage crops directly by their feeding activities, which reduce the plant's ability to manufacture food for use in producing the crop.

In reality, aphid feeding damage--sucking up nutrients from the plant--is often not the most important cause of damage to the crop. Aphids and other insects with piercing-sucking mouthparts sometimes do most of their damage not by directly damaging plant tissue but by transmitting plant viruses to the plant in the course of their feeding activities.

But the way in which aphid and other insects transmit viral diseases is much, much more complicated than simply sticking their stylets--the needly part of the insect that pierces the plant cell to feed--into plant tissues and injecting the viruses. And that's the substance of plant pathologist Tom Pirone's research: to find out exactly how the transmission process works and then to find a means to control diseases by blocking virus transmission from insect to plant.

Pirone and his colleagues have discovered that an extremely widespread and damaging family of aphid-transmitted viruses--called potyviruses--can't be transmitted without the aid of a special protein, a helper factor that the virus manufactures in an infected plant but which is not part of the virus particle itself.

The helper factor, according to Pirone's research, acts like a glue that attaches the virus to the stylets. Without the helper, virus acquired from an infected plant passes into the gut of the insect and cannot be transmitted to healthy plants.

And that finding may help scientists develop plants that make it difficult, if not impossible, for aphids to transmit these potyviruses. Pirone believes that it may be possible to genetically engineer plants to produce defective versions of the helper protein that would interfere with the action of the virus-encoded one. Other research in Pirone's lab has shown that certain oils sprayed onto leaves block the action of the helper protein. He suggests that plants might be engineered to extrude materials onto leaf surfaces that would act in a similar manner. Alternatively, the bacteria that naturally occur in large populations on leaf surfaces could be engineered to produce such interfering compounds.

Driverless Tractors

Up 'til now, farmers didn't need a road map to work their fields with their tractors. But now, things might be changing for the better--with a road map, sort of.

Agricultural engineer Tim Stombaugh is working on modifications to a tractor that would allow the tractor to steer itself around the field. Now, wouldn't that be nice. Just sit back, relax, and let it happen. Maybe work on your tan. Re-read War and Peace.

Besides cutting down on the monotony for the tractor operator (circling 'round and 'round the field, or back and forth as in seeding crops), the machine can help reduce soil compaction caused by large machines, precisely lay down agrichemicals without overlap, and can permit night-time working of fields, when it would be too dark to see where the tractor has already been.

Stombaugh calculates that it would cost a farmer somewhere between $5,000 and $15,000 to outfit a small tractor with the device, which relies on a computer hooked to the steering mechanism. In simple terms, the system relays signals from space to tell the machine both where it's been and where it's going.

So far, the system has worked pretty well through the paces Stombaugh has assigned it. The retrofitted tractor was set in a field about 35 feet off the line it was to travel; within 10 seconds of ignition, the tractor at eight miles per hour had righted itself and never deviated from its assigned path. He's also working on the concept to help guide spray equipment for greater precision.

Stombaugh admits he's still working on the system and that it won't be commercially available for a while; but early research has shown the concept is workable, relatively inexpensive, and has tremendous promise for greater precision in agriculture. Now, if he could just put a computer on cars to steer clear of bad drivers.

Healthy Butterflies, Healthy Corn

When environmental activists at the World Trade Organization's meeting in Seattle in 1999 dressed as Monarch butterflies as part of their conspicuous protest of the growing of transgenic crops, the migratory insect became an icon of opposition to genetically engineered crops.

This was due in part to a laboratory study at Cornell University suggesting that Monarch caterpillars feeding on milkweed plants dusted with pollen from the transgenic corn showed stunted development and a higher incidence of death. The transgenic corn had encoded into its cells a gene that produces a protein identical to that produced by Bacillus thuringiensis , a naturally-occurring bacterium. That protein is lethal to European corn borers.

That modest study at Cornell resulted in a flurry of research activity concerning all facets of the monarch butterfly and its feeding and reproductive habits, including a study by UK entomologist Ken Yeargan and undergraduate student Chanda Bartholomew.

Their study found that the time when the transgenic corn sheds its pollen does not coincide with the sensitive reproduction time of the Monarch butterflies in Kentucky. The Monarch butterfly lays her eggs on the milkweed plant that is widespread throughout the U.S. sometime after pollen shed. Other research has shown that the chemical in the pollen shed by transgenic corn is quickly degraded by sunlight. Thus, the butterflies can lay their eggs safely as long as there is opportunity for degradation of the chemical after pollen shed.

"Our research showed that the Monarch's reproduction occurs after pollen shed in corn grown Kentucky. That finding suggests that concern about Monarch butterfly reproduction being impeded by growing of the transgenic corn in Kentucky is exaggerated," Yeargan said. In Kentucky, thousands of acres of transgenic corn are grown annually.

Further, he noted, because the transgenic corn supplies its own naturally-occurring pesticide against the potentially damaging European corn borer, farmers use considerably less pesticide to grow their crop than if they grew conventional varieties of corn.

Glowing Success

When they were first developed, PCBs (polychlorinated biphenyls) had amazing properties. They were nonflammable, were chemically stable, and had electrical insulating properties. Because of these qualities, they were used widely in a variety of products including heat transfer systems, fluorescent lamp ballasts, television sets, and electrical appliances. They also were used as plasticizers in paints, plastics, and rubber producers, and in dyes and carbonless copy paper, among other products.

However, scientists later learned that PCBs are also highly toxic substances that persist in the environment for years and years. They are also suspected carcinogens, and cause a slew of reproductive, neurologic, and immunological disorders in animals and people. They are particularly troublesome because they are not only long lived in the environment, they move from the soil and water to fish and ultimately people at the end of the food chain. And although their manufacture was made illegal in 1976, Kentuckians are still warned by the Department of Water to restrict their consumption of fish from several local rivers and lakes, including the entire length of the Ohio river and portions of the Mud River, Drakes Creek, and Green River Lake, because of PCB contamination in the fish flesh.

Wide-scale field sampling and laboratory testing of soil for contamination using current technologies are almost insurmountable tasks. But researchers in UK's Agronomy Department (Elisa D'Angelo) and Chemistry Department (Sylvia Daunert) may make testing for PCBs in soil and water relatively easy. She is testing the use of biosensors--genetically engineered microorganisms that detect specific pollutants--developed by Daunert that detect even low levels of PCBs and their degradation intermediates in soil and water samples. The biosensors she's using are genetically engineered soil bacteria Pseudomonas putida . The bacteria glow when exposed to PCBs.

"The microorganisms glow when PCBs are present and glow even brighter as the concentration increases. With this technology, we can survey a large number of soil and water samples quickly and inexpensively, which should allow us to notify the public of potential health risks in water supplies and in soils," D'Angelo said.

Once PCBs are detected, scientists can take steps to remediate the soil or water. PCBs and similar compounds are unusual in that their degradation works best in environments with both anaerobic (without oxygen) and aerobic (with oxygen) conditions.

"If only one condition is present, PCBs are only partially transformed and some of their intermediary compounds are even more toxic than the PCBs themselves," she said.

In a related study, D'Angelo and graduate student Terry Meade are investigating the prospect of enhancing PCB degradation in soils by switching back and forth from flooded to drained conditions, and employing wetland plants that transport oxygen from air to the root zone, by diffusion through open spaces in the plants' tissues. Both activities promote the necessary sequential anaerobic and aerobic microbial processes required for PCB detoxification.

Zinc, Zinc Up, Every Body

Without ever meeting you, Bernie Hennig can predict with 40 percent accuracy the cause of your eventual death: cardiovascular disease, which includes both heart attacks and strokes. He isn't a soothsayer; simply, the numbers are on his side. Forty-one percent of all deaths in the U.S. are attributed to cardiovascular disease. But Hennig's research may help reduce that percentage significantly.

Cardiovascular disease, or atherosclerosis, has been linked to overconsumption of fat and lack of protective nutrients such as antioxidants and micronutrients. Over time, a build-up of deposits of fatty substances, cholesterol, calcium and other substances on the interlining of our arteries occurs. When the build-up gets severe, blood flow becomes constricted and we suffer a heart attack or stroke. And while our own genetic makeup is an important determinant of our predisposition to develop these diseases, what we eat also may have a substantial influence on when--or even whether--we develop cardiovascular disease.

Hennig, a human nutrition researcher in the Department of Animal Sciences, has conducted experiments in which endothelial cells--those which make up the lining of veins and arteries--are subjected to various compounds which are thought to either hasten or delay the onset of vascular disease. This U.S. Department of Agriculture and National Institute of Health-funded research focuses on the injurious effects of individual fats, including fatty acids, cholesterol, and their oxidation derivatives, and the protective effects of certain vitamins and minerals, such as vitamin E and zinc.

His findings suggest that both vitamin E and zinc, in particular, may provide some protection to these cells, keeping them healthy and free flowing. While these results are derived from test tube experimentation, they may provide the first steps in addressing how nutrition influences whether we develop cardiovascular disease. For those of us who have a predisposition to cardiovascular disease, Hennig's findings may help us eat the right foods to delay the onset of cardiovascular disease or avoid it altogether.

Fresh Air

Scientists have known for a long time that growing vegetation on reclaimed mining land improves water quality in the surrounding area considerably. Because the vegetation reduces erosion on the otherwise bare land, planting the land to something-- anything--keeps creeks and streams freer of sediment from runoff.

What is becoming more appreciated is the fact that vegetation, especially trees, helps reduce carbon dioxide levels--a byproduct of combustion and the natural decay of plant material --in the atmosphere. Excessive levels of carbon dioxide free in the atmosphere have been linked to the thinning of the ozone layer--the greenhouse effect that may influence the earth's weather and temperature.

UK foresters have just embarked on a three-year study to discover improved methods to plant trees on strip-mined land and to evaluate different methods for minimizing sediment in creeks and streams. The research also will measure the ability of those newly-planted trees to sequester--or remove from the atmosphere--carbon dioxide.

Trees naturally sequester carbon dioxide by removing it from the air during photosynthesis and immobilizing it (by incorporating it into plant tissue) until the tree is either burned or dies and decomposes.

The research, which will be conducted in cooperation with UK's Department of Mining Engineering and Department of Biosystems and Agricultural Engineering, is funded by $2 million in grants from the U.S. Forestry Service and the U.S. Department of Energy. The grants will be matched by mining companies which will provide land, labor, and equipment to replant the trees.

The UK foresters hope that their new project will not only provide a high-value crop on the land, but also will improve water and air quality for their efforts. In the project, researchers will plant 3,000 acres at three sites to high-value trees and measure how their presence influences water and air quality. The three sites will include two in the eastern coalfields and one in the western coalfield.

Currently, some quarter of a million acres--about the size of a square 20 miles by 20 miles--have been strip mined in Kentucky, and another 1.6 million acres have the potential for coal extraction using strip mining techniques.

Trench Warfare


The term conjures up all manner of thoughts and they are all bad. They can chew through the very timbers holding up your house. In the old days, gallons and gallons of pesticides were trenched around your house and injected under floors and into walls at every possible place were the termites might enter in efforts to eradicate the destructive insects.

Then, professional exterminators decided to use baits around the perimeter of the home to avoid the drilling and pumping of pesticides in the home. The termite professional would bury traps in your yard that would intercept--and kill--the termites. The problems with the bait stations were they were costly, labor intensive, and took a longer time to reduce the termite population. The good part, which consumers loved, was that there was no drilling inside the house or pulling back of the carpets.

Now termite control might be changing again, for the better, thanks to University of Kentucky entomologist Mike Potter.

Potter, in a preview of one of newer non-repellent liquids that were formulated to be used by drilling and injecting into the home, suggested to the companies developing the newer pesticides they consider using the active ingredients of the baits as a trench around the house. He reasoned that because the chemical doesn't repel termites--meaning that they don't sense it in the soil--they could be used to kill termites just as the chemicals in bait boxes killed termites. They asked him to try out that method, which he believed would be quicker, more effective, and less disruptive for homeowners.

Potter, along with research specialist Anne Hillery, tried the new chemicals on some old tobacco barns in Central Kentucky that were badly infested with termites. He trenched the newer, safer chemical around the perimeter of the old barns and found that the chemical not only formed a barrier, but also killed those already infesting the barns. In other words, termites in the barn were killed by trenching around the barn--without any injections inside the structure.

Potter then tried it on some old houses severely infested with termites. The termites were so invasive that he could record their chomping through the house's timbers, using acoustic emission detectors. Using a trenching method, he used a reduced amount of the termiticide around the structure. Within three months the termites were silent--and dead.

The reason trenching with the new chemicals kills termites already inside the house has to do with the termites' behavior. They are social insects and traffic back and forth between the inside of the house and the outside, so even if they don't get into treated soil, they rub up against those that do, and they are killed, too.

Potter is now working with manufacturers to gain Environmental Protection Agency clearance to use the new termiticides as exterior-only treatments. The outcome will be less costly, faster-acting treatment of termites, and homes won't be disrupted by drilling and injecting of chemicals.        

The Voices of Rural Poverty

The rural poor are well hidden. When most people think of poor people, the image of the urban poor, living in slums, or worse, comes to mind. But in Kentucky--and throughout the Southeast-- rural poor outnumber urban poor and their plight is often more difficult to ameliorate than that of their urban counterparts.

Rural sociologist Tricia Dyk has been studying the effects of welfare reform on rural families as part of a multi-state research effort to assess how rural poor families are coping. Her findings are provocative.

Her research has included interviewing 21 Kentucky women whose families are living below the poverty threshold in rural Kentucky. As she explains, these families are on the edge. Each of poverty mothers is asked about their lives in poverty in a two-hour interview.

Early analysis of the interviews shows that the rural poor often face poverty because of lack of jobs in the area. And because they live in poverty, they depend a great deal on their extended families to help them cope with their day-to-day existence--from helping with childcare to providing short-term loans when the money runs out. Many are seemingly locked into poverty because of lack of education that would allow them to compete successfully for above-minimum-wage jobs. Further, most don't have the resources to relocate where more jobs are available, because of their considerable dependence on their extended families.

Dyk's research, which looks at rural poverty through the eyes of those who live it every day, will provide another view of the effects of welfare reform as the Congress deliberates adjustments to the welfare reform laws in 2002.