Study on yield and yield components of hybrid and open-pollinated rapeseed (Brassica napus L.) cultivars in competition with the wild mustard (Sinapis arvensis L.)

In order to study the effect of wild mustard on oil، grain، biological yield and yield components of eight Rapeseed cultivars (two hybrids and six open-pollinated)، an experiment was conducted using a factorial arrangement of treatments in a randomized complete block design with three replications during 2006-2007 growing season at the research field of Abooreihan Campus، University of Tehran، Pakdasht. The treatments were consisted of weed-free and weed-infested of eight rapeseed cultivars. Oil، grain، biological yields، oil percent، number of plants/m2، number of pods/plant، number of seeds/pod، 1000-grain weight were measured. Results showed significant differences in all traits among cultivars. Oil، grain and biological yields، and number of pods/plant reduced significantly due to competition. But، no significant differences were observed for oil percent، number of plants/m2، number of seeds/pod and 1000-grain weight between weed-free and weed-infested conditions. Elite، Ebonite and Zarfam produced more yield under both weed-free and weed-infested conditions. Lowest amount of yield under of weed-infested was belonged to Okapi. Generally، Elite produced more oil، grain yield and number of pods/plant in weed-infested plots. Overall، cultivar Elite could be considered as the best cultivar under weed-infested conditions.