تأثير شاخص هاي رشد بر توان رقابتي ارقام كلزا (Brassica napus) با علف هرز خردل وحشي (Sinapis arvensis)

The effect of growth indices in competitive ability of some canola (Brasica napus) cultivars against wild mustard (Sinapis arvensis).

In order to evaluate the interference of wild mustard on growth indices of Canola cultivars an experiment was carried out in Agricultural and Natural Resources Research Institute of Gorgan during 2005-2006 growing season. The experiment was established as a randomized completely block design in a factorial arrangement of treatments with three replications. Canola cultivars, Zarfam, Sarigol, Talayh, R.G.S 003, Option 500, Hayola 401 and Hayola 330 were kept under weed free and weed infested conditions. The results indicated that, wild mustard resulted in reduction of canola dry matter, leaf area index, leaf area index duration and crop growth rate, significantly. The maximum dry matter, leaf area index and crop growth rate in control plots (weed free treatment) belonged to Hayola330 cultivar. The maximum and minimum reduction rate of dry matter and leaf area index of canola cultivars was obtained in control 0ption500 and Zarfam cultivars respectively. Results revealed, cultivars with higher leaf area index, relative leaf area expansion rate and better vertical leaf area distribution could be more competitive in weed-infested conditions, and can be used in breeding programs to enhance competitive ability of canola cultivars.