Response of field beans ( Vicia faba L cv. Maris Bead) to time of sowing, plant population, nitrogen, and irrigation

Four populations of field beans ( Vicia faba L.), ranging from 45 to 140 plants/m 2 were established in late April and mid May, and at populations from 22 to 126 plants/m2 in mid August and late September. A seed yield of 516 g/m 2 was obtained from high poulations in autumn and was independent of time of sowing in that season. However, a seed yield of only 300 g/m 2 was obtained from early spring sowing. Delaying spring sowing by a further six weeks reduced seed yield to 147 g/m 2 . Irrigation increased seed yield of both spring and autumn sowings but did not completely compensate for the yield reduction which was caused by spring sowing. Foliar application of 10 kg/ha of nitrogen (N) applied to plants before flowering had no effect on yield or nitrogen concentration of seeds.