Response of canola (Brasica napus L.) to plant densities of mustard (Sinapis arvensis L.) with emphasis on agonomic control

In order to study the response of canola to plant densities of mustard (Sinapis arvensis L.) with emphasis on agronomic control in Ahwaz condition, an experiment was conducted in 2006-2007 cropping season at Ramin Agricultural and Natural Resources University. The experimental design was split plot arrangements in a randomized complete block design with four replications. Mustard plant densities (0, 7, 14, 21 and 35 plants m-2) were assigned to main plots and canola plant densities (60, 80 and 100 plants m-2) were randomized in sub plots. The results indicated that grain yield, biologic yield, harvest index (HI), silique number sub-branch-1 and grain number silique-1 were significantly affected by interaction between canola and mustard plant densities. Silique number main branch-1, diameter of canopy and first sub-branch height were affected by mustard plant densities. Thousand grain weight, final plant height and sub-branch number plant-1 was not affected by treatments. Furthermore, highest yield loss of 91% was recorded in 35 plants m-2 of mustard in 80 plant m-2 densities of canola. Results also showed no significant difference between canola plant densities (except in pure stand) in any mustard plant densities for grain yield. Therefore, the lower canola plant density (60 plants.m-2) could be recommended to decrease seed consumption when mustard is competing with canola in field conditions.