Competition of Wild Oat in Wheat and Barley

Wild oat (Avena fatua L.) competition increased the losses in yield of both wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.) with increased densities of seedlings. At Fargo in 1965, wild oat densities of 70 and 160 seedlings/sq yd reduced the wheat yield 22.1% and 39.1%, respectively, compared to the wild oat-free check. Similar wild oat densities reduced the barley yield 6.5% and 25.9%, respectively. The addition of nitrogen and phosphorus fertilizer reduced the yield loss caused by wild oat 2 out of 3 years of the experiment. Although a considerable yield reduction occurred in barley and wheat, percent protein and seed size were not influenced noticeably.