تاثير خردل وحشي بر عملكرد و اجزاي عملكرد گندم پاييزه در مقادير و زمانهاي مصرف نيتروژن

Investigation of amount and timing of nitrogen application effects on wild mustard (Sinapis arvensis) impact on yield and yield components of winter wheat

To study the amount and timing of nitrogen application effect on wild mustard (Sinapis arvensis) impact on yield and yield components of winter wheat, an experiment was conducted in 2001 at farm research of Mashhad college of agriculture. Split plot design with three replications was used with factorial of weed density (0, 8, 16, and 32 Plant nv2) and nitrogen (low = 100, optimum = 150, and high = 225 Kg.ha1) as main plot. The sub plot included nitrogen split pattern {P1 =1/3 at planting time + 2/3 at tillering, P2=1/3 at planting time + 1/3 at tillering* 1/3 at shooting} Three parameters rectangular hyperbolic model, was fitted to yield and yield components data. Our results showed that nitrogen split pattern had no significant effect on competition between wild mustard and wheat. The study of yield and yield components of wheat demonstrated that increasing wild mustard density reduced wheat biological and economic yield due to reduced tiller and ear number per unit area and seed per ear. The economic yield reduction was grater than biological yield. In each condition competitive ability of individuals of wild mustard in high and low nitrogen rates was higher than optimum nitrogen rate.