Seed yield of grazing-tolerant alfalfa germplasms

Alfalfa (Medicago sativa L.) cultivars tolerant to grazing usually have poor seed yields. This study compared grazing-tolerant alfalfa cultivars and germplasms to hay-type cultivars for seed yield in Georgia and determined the relationship of certain plant characters to seed yield. Hay-type (‘Apollo, and ‘Florida 77’) and grazing-type (‘Spredor II, and ‘Travois’) cultivars and two alfalfa germplasms selected for survival under continuous grazing in Georgia (GA-GC and GA-WCG) as well as the representative base populations of GA-WCG were established as replicated spaced plants for seed production over a 2-yr period. Measurements of raceme number, seeds per pod, and seed weight did not attain biologically significant correlations with seed yield. Grazing-tolerant germplasms, GA-GC and GA-WCG, produced seed and forage yields higher than the grazing- type cultivars and equivalent to the hay-type cultivars. Comparisons between GA-WCG and its base population indicate that seed and forage yields were maintained while the population was shifted toward a more decumbent growth habit and earlier fall dormancy. In this experiment alfalfa seed and forage yields were not sacrificed in the development of grazing-tolerant cultivars.