Effect of row spacing and sowing rate on seed production of lucerne ( Medicago sativa L.) cv. Grasslands Oranga

Abstract The effects of row spacing (15, 30, 45, and 60 cm) and sowing rate (1, 3, 6, and 12 kg/ha) on lucerne seed yield and its components were investigated at Massey University, Palmerston North, New Zealand, over two seasons. In the first year, seed yield from the 15 cm row spacing was significantly lower than that from the 30, 45, and 60 cm row spacings, whereas sowing rate had no effect on seed yield. In the second year crop, row spacings did not significantly affect seed yield, but the seed yield from the 1 kg/ha sowing rate was significantly greater than that for other sowing rates because harvestable racemes/m 2 and thousand seed weight were significantly increased. Seed yield over 2 years of the experiment was highest at the 1 kg/ha sowing rate and for the 30 and 45 cm row spacings. However, there were no significant interactions between row spacing and sowing rate for seed yield. The average seed yield for all treatments was 127 and 187 kg/ha for the first and second year respectively. Neither row spacing nor sowing rate had any effect on the quality of harvested seed.