INFLUENCE DES CULTIVARS, DES DATES ET DES DOSES DE SEMIS SUR LE RENDEMENT ET LA QUALITÉ DE LA LUZERNE SEMÉE EN FIN D’ÉTÉ

Abstract

The effects of cultivars, date and rate of seeding on the yield and quality of alfalfa (Medicago sativa L.) seeded at the end of summer and harvested the year after was studied from 1971 to 1975 on a Kamouraska clay. Seeding in early August gave the best results; seeding should not be carried out after mid-August. Differences between cultivars were more important on the third than on the first cut. Aftergrowth was an important factor on yield during the first year of harvest. Seeding rate did not always affect the yield, but the 6,7 kg/ha rate yielded less than the 13,4 kg/ha rate at the first cut and when the cuts were summed. The combined effects of the three factors studied indicates the importance of the seeding date on the height, cover and yield of alfalfa. Digestibility and crude protein content of the dry matter were affected more by seeding dates than by cultivars. The effect of cultivars on quality was variable and seeding rates had no effect. The variation in forage quality may be attributed to a difference in maturity of the plant at harvest, rather than only to the factors studied.Key words: Medicago sativa L., cultivar, date, rate, yield, quality