Five Decades of Alfalfa Cultivar Improvement
- JoAnn F. S. Lamb *a,
- Craig C. Sheafferb,
- Landon H. Rhodesc,
- R. Mark Sulcd,
- Daniel J. Undersandere and
- E. Charles Brummerf
- a USDA-ARS Plant Science Research Unit and Dep. of Agronomy and Plant Genetics, Univ. of Minnesota, 411 Borlaug Hall, 1991 Upper Buford Circle, Saint Paul, MN 55108
b Dep. of Agronomy and Plant Genetics, Univ. of Minnesota, 411 Borlaug Hall, 1991 Upper Buford Circle, Saint Paul, MN 55108
c Dep. of Plant Pathology, Ohio State Univ., 2021 Coffey Road, Columbus, OH 43210-1086
d Dep. of Horticulture and Crop Sci., Ohio State Univ., 2021 Coffey Road, Columbus, OH 43210-1086
e Dep. of Agronomy, Univ. of Wisconsin-Madison, 1575 Linden Drive, Madison, WI 53706
f Raymond F. Baker Center for Plant Breeding, Dep. of Agronomy, Iowa State Univ., 1204 Agronomy Hall, Ames, IA 50010
Previous research has implied that forage yield in released alfalfa (Medicago sativa L.) cultivars declined slightly between 1978 and 1996. Our objective was to compare alfalfa cultivars released during the past five decades side by side in replicated yield trials to test for any changes in forage yield across time. Ten cultivars, two from each of the five decades, four recently released cultivars, and two check cultivars were compared for forage yield, persistence, and nutritive value at four locations. Cultivars were established in May 1999 at Iowa, Wisconsin, Ohio, and Minnesota. Forage was harvested three to four times in each of four production years depending on location. Plots were subsampled for nutritive value analyses for the first and third harvests in 2000 and 2001. Year × location × cultivar-release date interactions demonstrated that forage yield and final stand densities differed among the cultivars in each year of the experiment at each location. Nutritive value traits were similar among all cultivars. Evidence for changes in forage yield for cultivars released between 1940 and 1995 was environmentally dependent. In environments where conditions lead to plant stand losses, recently released cultivars with multiple disease resistance had a yield advantage over older cultivars, but in environments where no differences in plant density occurred across time, older cultivars yielded the same as recent cultivars.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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