YIELD COMPONENTS OF ALFALFA (Medicago sativa L.) VARIETIES

Alfalfa (Medicago sativa L.) is the most important legume forage for dairy cattle feed in Mexico. The objective of this study was to assess the productive response of five varieties of alfalfa in cutting intervals defined seasonally. Our hypothesis was that the San Miguelito variety is the most productive among the evaluated varieties. The varieties San Miguelito, Jupiter, Atlixco, Via lactea and Cuf 101 were randomly distributed in 20 experimental plots of 12x9 m, in a completely randomized blocks design with four replications. Evaluations included yield feed, leaf:stem ratio, weight per stem, stem population per m(2), plant population per m(2) and botanical and morphological composition. Jupiter and Cuf 101 showed the highest yield (20 275 and 13 350 kg MS ha(-1)). Leaf: stem ratio was higher in Cuf 101 and smaller in Jupiter. The weight per stem was higher in Jupiter and lower in Cuf 101. Jupiter and Atlixco expressed the highest stem density (641 stems per m(2)) and Cuf 101 showed the lowest (417 stems per m(2)). The highest leaf quantity occurred in autumn and winter, and during spring weeds increased in Cuf 101. The yield seasonality was high, spring and summer were the periods with greater production, due to their density and weight per stem. The variety with the highest production was Jupiter, and Cuf 101 was the variety with smallest production.