DRY-MATTER AND SEED YIELD OF MEDITERRANEAN ANNUAL LEGUME SPECIES

Knowledge of the effects of seeding rate, irrigation, and forage harve st management on annual legume crops is essential for their proper agr onomical exploitation. Cultivars and ecotypes of berseem clover (Trifo lium alexandrinum L.), common vetch (Vicia saliva L.), and field-bean (Vicia faba L.) were compared at two seeding rates, with and without i rrigation, and under two harvest managements. These experiments were c onducted in Foggia (southern Italy) during 1990 and 1991. Irrigation i ncreased and stabilized forage and seed production reducing the conseq uences of erratic rainfall. Mean dry matter and seed yield increases d ue to irrigation were, respectively: 26 and 14% in common vetch, 25 an d 9% in field-bean, and 24 and 28% in berseem clover. Berseem clover s howed an increase of 48%, in seed yield with forage harvest management under irrigation. Seeding rate interacted mainly with irrigation trea tment and length of vegetative period. The high seeding rate under irr igation in common vetch and field-bean increased forage production mor e than seed yield. The herbage and seed yield components that responde d to the high seeding rate under irrigation were plant height, stems p er 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 specie s represent genotypes with superior genetic potential for dry matter p roduction and seed yield under a Mediterranean environment.