Online Publications

PR-473

2002 Red Clover Report

R. Spitaleri, J.C. Henning, N.L. Taylor, G.D. Lacefield, D.C. Ditsch, and G.L. Olson

Introduction

Red clover (Trifolium pratense) is a high-quality, short-lived, perennial legume that is used in mixed or pure stands for pasture, hay, silage, green chop, soil improvement, and wildlife habitat. This species is adapted to a wide range of climatic and soil conditions and therefore is versatile as a forage crop. Stands are generally productive for two or three years, with the highest yields occurring in the year following establishment. Red clover is used primarily as a renovation legume for grass pastures. It is a dominant forage legume in Kentucky because it is relatively easy to establish and has high forage quality, high yield, and animal acceptance.

Yield and persistence of red clover varieties are dependent on environment and pressure from diseases and insects. The most common red clover diseases in Kentucky are southern anthracnose, powdery mildew, sclerotinia crown rot, and root rots. High yield and persistence (as measured by percent stand) are two indications that a red clover variety is resistant to or tolerant of these diseases when grown in Kentucky.

This report provides current yield data on red clover varieties included in yield trials in Kentucky as well as guidelines for selecting red clover varieties.

Important Considerations in Selecting a Red Clover Variety

Local adaptation and persistence. The variety should be adapted to Kentucky as indicated by superior performance across years and locations in replicated yield trials such as those reported in this publication. High-yielding varieties are generally also those varieties that are the most persistent. Red clover generally produces measurable yields for three years, with the year of establishment considered as the first year. The highest yields occur in the year following establishment.

Seed quality. Buy high-quality seed that is high in germination and purity and free from weed seed. Buy certified seed or proprietary seed of an improved variety. An improved variety is one that has performed well in independent trials such as are reported in this publication. Other information on the label will include the test date, which must be within the previous nine months, the level of germination, and other crop and weed seed. Order seed well in advance of planting time to assure that it will be available when needed.

Description of the Tests

This report summarizes studies at Princeton (sown in 2000), four at Lexington (two sown in 2000, one in 2001, and one in 2002), one at Eden Shale (sown 2000), and one at Quicksand (sown 2001). The soils at Princeton (Crider), Lexington (Maury), and Quicksand (Pope) were well-drained silt loams. Eden Shale has a Nicholson silt loam soil. All are well suited to red clover production. Plots were 5 x 15 feet and were arranged in a randomized complete block design with four replications at every location.

Seedings were made at 12 pounds of seed per acre into a prepared seedbed using a disk drill. The first cutting in the seedling year was delayed to allow the red clover to completely reach maturity as indicated by full bloom, which generally occurs about 60 to 90 days after seeding. Otherwise, harvests were taken when the red clover was in the bud to early-flower stage using a sickle-type forage plot harvester. Fresh weight samples were taken at each harvest to calculate percent dry matter production. All tests for establishment, fertility, and harvest management were managed according to University of Kentucky Cooperative Extension Service recommendations. Weeds were controlled so as to not limit production or persistence.

Results and Discussion

Weather data for Quicksand, Eden Shale, Lexington, and Princeton are presented in Table 1. After a wet spring, the 2002 summer in Kentucky was the fourth driest and hottest on record. This adversely affected number of harvests and total yield for 2002.

Yield data (on a dry matter basis) are presented in Tables 2 through 8. Yields are given by cutting date and as total annual production. Varieties are listed in order from highest to lowest total production (for the life of the test). Experimental varieties are listed separately at the bottom of the tables and are not available commercially.

Statistical analyses were performed on all red clover data (including experimental varieties) to determine if the apparent differences are truly due to variety. Varieties not significantly different from the top variety within a column are marked with one asterisk (*). To determine if two varieties are truly different, compare the difference between the two varieties with the Least Significant Difference (LSD) at the bottom of the column. If the difference is equal to or greater than the LSD, the varieties are truly different when grown under the conditions at a given location. The Coefficient of Variation (CV), which is a measure of the variability of the data, is included for each column of means. Low variability is desirable, and increased variability within a study results in higher CVs and larger LSDs.

Certified Kenland continues to rank near the top of tests. It is important to note yield differences between certified and uncertified Kenland red clover. Most Kenland offered for sale is uncertified, but our tests show it is significantly lower in yield than certified Kenland.

In addition to the commercially available varieties and experimental lines, selected "common" red clovers are included in the variety tests for comparison. Common red clover, generally sold as "medium red clover variety unknown," is unimproved red clover with unknown performance. Several years of testing show only about one out of every 10 common red clovers is as productive as the certified or proprietary red clovers. In Kentucky, the yield advantage of seeding better red clovers compared to common types is 3 to 6 tons of dry matter over the life of the stand.

Table 9 summarizes information about proprietors, distributors, and yield performance across years and locations for all varieties currently included in this report. Varieties are listed in alphabetical order, with the experimental varieties at the bottom. Experimental varieties are not available for farm use, but commercial varieties can be purchased from dealerships. In Table 9, a shaded area indicates that the variety was not included in that particular test (labeled at the top of the column), and a clear block means that the variety was included in the test. A single asterisk (*) means that the variety was not significantly different from the highest-yielding variety. Look at data from several years and locations when choosing a variety of red clover rather than results from one test year as is reported in Tables 2 through 8. Make sure seed of the variety selected is properly labeled and will be available when needed.

Summary

Red clover can be a productive component of pasture and hayfields. Choose a variety with proven performance in yield and persistence.

Other College of Agriculture publications related to the establishment, management, and harvesting of red clover available from the local county Extension office are listed below:

• AGR-1 Lime and Fertilizer Recommendations
• AGR-2 Producing Red Clover Seed in Kentucky
• AGR-18 Grain and Forage Crop Guide for Kentucky
• AGR-24 Kenstar Red Clover
• AGR-26 Renovating Hay and Pasture Fields
• AGR-33 Growing Red Clover in Kentucky
• AGR-64 Establishing Forage Crops
• AGR-90 Inoculation of Forage Legumes
• AGR-148 Weed Control Strategies for Alfalfa and Other Forage Legume Crops
• ENT-17 Insect Management Recommendations for Field Crops and Livestock
• PPA-10 Kentucky Plant Disease Management Guide for Forage Legumes

Authors

• R. Spitaleri: Research Specialist, Forages, UK Agronomy
• J.C. Henning: Extension Professor, Forages, UK Agronomy
• N.L. Taylor: Professor, Red Clover Breeding, UK Agronomy
• G.D. Lacefield: Extension Professor, Forages, UK Agronomy
• D.C. Ditsch: Extension Associate Professor, Feed Production, UK Agronomy
• G.L. Olson: Research Technician, Red Clover Breeding, UK Agronomy

Mention or display of a trademark, proprietary product, or firm in text or figures does not constitute an endorsement and does not imply approval to the exclusion of other suitable products or firms.

 

Table 1. Temperature and Rainfall at Bowling Green, Eden Shale, Lexington, and Princeton, Kentucky, in 2002.
	Bowling Green				Eden Shale				Lexington				Princeton
	Temp		Rainfall		Temp		Rainfall		Temp		Rainfall		Temp		Rainfall
	º F	DEP	IN	DEP	º F	DEP	IN	DEP	º F	DEP	IN	DEP	º F	DEP	IN	DEP
JAN	40	+6	3.70	-0.12	39	+9	2.84	+0.30	38	+7	2.12	-0.74	41	+7	3.79	-0.01
FEB	39	+1	0.91	-3.22	39	+6	1.24	-1.51	38	+3	1.28	-1.93	42	+4	2.40	-2.03
MAR	47	+1	7.60	+2.50	45	+2	6.09	+1.37	45	+1	7.93	+3.53	49	+2	8.18	+3.24
APR	60	+3	7.30	+2.98	59	+5	4.71	+0.56	58	+3	4.19	+0.31	63	+4	5.72	+0.92
MAY	64	-2	5.56	+0.62	62	-1	5.68	+1.27	61	-3	4.36	-0.11	66	-1	9.04	+4.08
JUN	76	+1	1.20	-2.97	75	+4	4.54	+0.77	74	+2	2.45	-1.21	77	+2	1.88	-1.97
JUL	80	+2	3.57	-1.17	79	+4	1.10	-3.43	78	+2	1.10	-3.90	81	+3	2.13	-2.16
AUG	80	+3	5.10	+1.59	79	+5	0.37	-3.36	77	+2	0.95	-2.98	80	+3	2.06	-1.95
SEP	75	+5	9.46	+5.74	73	+5	5.13	+1.94	72	+4	4.90	+1.70	74	+3	5.90	+2.57
OCT	62	+4	5.24	+2.22	56	-1	2.69	-0.30	55	-2	5.61	+3.04	59	0	6.12	+3.07
NOV	48	+2	5.00	+0.57	44	-1	3.13	-0.42	43	-2	3.76	+0.37	47	0	2.49	-2.14
DEP is departure from the long-term average for that location.