SEED RATES FOR SOFT WHITE WINTER-WHEAT IN SOUTHWESTERN ONTARIO

This study was undertaken to determine the optimum seed rate for soft white winter wheat (Triticum aestivum L.) cultivars currently grown in southwestern Ontario (> 2900 corn heat units) where 65 % of Ontario's wheat is grown. The currently recommended density of 240-400 plants m -2 was determined using obsolete cultivars. Two popular cultivars, Har us, which tillers abundantly, and Rebecca, which tillers less, were gr own from 100 to 600 seeds m-2 in increments of 100. The optimum seed r ate for grain yield was 435 seeds m-2. This rate appears to be suitabl e for a range of genotypes adapted to southwestern Ontario. There was no interaction for yield among cultivars, years and locations. Yield w as not related to tillering capacity, as the lower the plant density t he more seeds there were per head.