Reaction of grain yield and its components of canola (Brassica napus L.) cultivars in competition with wild mustard (Sinapis arvensis L.) in Gorgan.

In order to determine grain yield and its components of seven canola cultivars in competition with wild mustard, a field experiment was conducted at the Araqai Mohaleh agriculture research station in Golestan province, in 2005-2006 growing season. The experiment was established as factorial arrangement using a randomized complete blocks design with three replications. The seven canola cultivars (Hayola‏401, Hayola‏330, RGS‏003, Option500, Sarigol, Zarfam and Talayeh) were planted in weed-free and weed-‏infested (with 30 wild mustard plants per square meter) plots. Grain yield, harvest index, number of pods/plant, number of grains/pod and 1000-grain weight were measured. Result showed significant differences in grain yield among cultivars. Results also indicated significant differences in yield components in weed-free and weed-infested conditions. Mean comparisons among cultivars showed that Hayola330 produced the highest grain yield with average of 2836 kg/ha and Talayeh produced the lowest grain yield in weed-free condition with average of 1729 kg/ha. Under weed-infested condition Hayola330 produced the highest grain yield with average of 870 kg/ha and option500 had the lowest grain yield with average of 101 kg/ha. Although, Hayola330 produced the highest grain yield in weed-infested but it had higher yield loss than Zarfam cultivar. Therefore, the degree of tolerance in canola cultivars differed, in competition with wild mustard. To develop cultivars with high grain yield in both weed-free and weed-infested conditions are to be included as a strategy in canola breeding program.