Seeding rate effect on seed yield and yield components of alfalfa (Medicago sativa).

A four year field experiment was conducted at the Research Site of Tehran Province Agricultural and Natural Resources Research Center in Varamin, Iran to study the effect of seeding rate on seed yield and seed yield components of alfalfa (Medicago sativa) during 2005-2008 growing seasons. Seeding rate treatments were 2.5 kg ha-1 (SR1), 5.0 kg ha-1 (SR2), 7.5 kg ha-1 (SR3), 10.0 kg ha-1 (SR4) and 12.5 kg ha-1 (SR5). Seed yield and seed yield components (number of pods per m2, number seeds per pod and 1000-seed weight) were determined for all treatments. The statistical results of the study indicated that seeding rate significantly (P = 0.01) affected seed yield and number of pods per m2, but there was no significant difference in number seeds per pod and 1000-seed weight. The maximum value of seed yield (805.0 kg ha-1) and number of pods per m2 (6610) was obtained in case of SR1 treatment. Conversely, the minimum value of seed yield (605.7 kg ha-1) and number of pods per m2 (4620) was observed in case of SR5 treatment. Therefore, 2.5 kg ha-1 was found to be more appropriate seeding rate in improving seed yield of alfalfa in the semi-arid lands of Varamin, Iran.