effect of wild mastard (sinapis arvensis l.) interference on yield and growth indexes of canola (brassica napus l.)

this research was carried out in the research field of aboureyhan campus, university of tehran during 2006-07 growing season to investigate the effect of sinapis arvensis l. interference on yield and growth indexes of different canola (brassica napus l.) varieties. the experimental design was a complete randomized block arrangement in factorial with three replications. eight canola varieties namely: elite, ebonite, okapi, zarfam, slm046, orient, licord and opera were planted in either pure or mixed cultivation with the weed. trend of dry matter (tdm) accumulation, leaf area index (lai), crop growth rate (cgr) and grain yield were investigated in the canola varieties. in general, the weed reduced growth indexes in canola varieties, but the response of canola varieties were different. elite and okapi were recognized as the most resistant and sensitive varieties in competition with the weed, respectively. elite variety produced the highest grain in mix treatment while the lowest one belonged to okapi variety, but in pure canola cultivation ebonite and opera yielded the maximum and minimum grain, respectively.