Spring Wheat (Triticum aestivum) Growth and Yield as Influenced by Duration of Wild Oat (Avena fatua) Competition

The effect of duration of wild oat competition on spring wheat yield and growth was determined in time-of-removal experiments conducted over a three year study period in Saskatchewan, Canada. Failure to remove wild oat reduced wheat yield 28 and 39% at wild oat populations of 64 and 188 plants per m2, respectively. Wheat yield was not reduced by wild oat densities of 64 or 118 plants per m2until the six- and seven-leaf stage of wild oat, respectively. Removing wild oat at 64 plants per m2before the seven-leaf stage and 118 plants per m2before the five-leaf stage did not increase wheat culm or fresh weight production.