DRY-MATTER AND SEED YIELD OF MEDITERRANEAN ANNUAL LEGUME SPECIES

Knowledge of the effects of seeding rate, irrigation, and forage harvest management on annual legume crops is essential for their proper agronomical exploitation. Cultivars and ecotypes of berseem clover (Trifolium alexandrinum L.), common vetch (Vicia saliva L.), and field-bean (Vicia faba L.) were compared at two seeding rates, with and without irrigation, and under two harvest managements. These experiments were conducted in Foggia (southern Italy) during 1990 and 1991. Irrigation increased and stabilized forage and seed production reducing the consequences of erratic rainfall. Mean dry matter and seed yield increases due to irrigation were, respectively: 26 and 14% in common vetch, 25 and 9% in field-bean, and 24 and 28% in berseem clover. Berseem clover showed an increase of 48%, in seed yield with forage harvest management under irrigation. Seeding rate interacted mainly with irrigation treatment and length of vegetative period. The high seeding rate under irrigation in common vetch and field-bean increased forage production more than seed yield. The herbage and seed yield components that responded to the high seeding rate under irrigation were plant height, stems per square meter for all legumes, pods per stem, and seeds per pod for field-bean and common vetch, and heads per stem and seeds per head for berseem. Adapted varieties and ecotypes identified within each species represent genotypes with superior genetic potential for dry matter production and seed yield under a Mediterranean environment.