INFLUENCE DES CULTIVARS, DES DATES ET DES DOSES DE SEMIS SUR LE RENDEMENT ET LA QUALITÉ DE LA LUZERNE L’ANNÉE DU SEMIS

Abstract

The effects of cultivars, seeding rates and dates on alfalfa (Medicago sativa L.) yield and quality in the seeding year were studied from 1971 to 1975 on a Kamouraska clay. Results showed the importance of seeding alfalfa before the end of May. Seedings made in early and in mid-May resulted in equivalent yield. Differences between cultivars were more important on the second than on the first cut. Regrowth was an important factor in the seedling year. The total yield of the Alfa cultivar is higher than Vernal and Narragansett and it is also higher for every combination of rates and seeding dates. Seeding rates were not an important factor except at the first cut where a rate of 6.7 kg/ha gave a lower yield than a rate of 13.4 kg/ha. Dry matter digestibility of Alfa is sometimes higher than for the other cultivars in the study. Late seeding generally increased the digestibility of the second cut dry matter, whereas rates of seeding have no effect on either first or second cut material. The crude protein content is not affected by seeding rates and the effects of cultivars are generally very small. With a delay in seeding dates the crude protein content of the second cut material is sometimes increased.Key words: Medicago sativa L., cultivar, date, rate