Abstract
SUMMARY A three-year study of the effects of sowing date, nitrogen application and seed rate on wheat showed that sowing in mid-October gave consistently greater grain yields than sowing in mid-September or mid-November because grains were larger and more numerous per head. Nitrogen increased yields but the effect decreased with later sowing. Nitrogen probably increased grain yield by increasing the number of ears, but this effect diminished with higher levels of nitrogen. Grain yield was only slightly influenced by seed rate, and the interaction of seed rate with sowing date or nitrogen was unimportant.