Environment Influences Green Foxtail (Setaria viridis) Competition with Wheat (Triticum aestivum)

Abstract
Temperature, soil moisture, green foxtail density, relative emergence dates, and soil fertility effects on green foxtail and spring wheat competition were evaluated in controlled environments. Green foxtail competition was highest at 30 C and without moisture stress. Early green foxtail emergence increased competition with wheat more than changes in temperature, soil moisture, or green foxtail density. At 30 C, wheat fresh weight was reduced 50% by green foxtail seeded 4 d before wheat, but only 13% by foxtail seeded 4 d after wheat. Doubling the nitrogen and total nutrient concentration did not increase wheat growth, but increased foxtail weight 41 and 75%, respectively.