Effect of boron application on some of morphological characteristics and grain yield, oil and nitrogen of spring canola (Brassica napus L.) in different sowing dates

A field experiment was carried out to study the yield, quality and some morphological traits responses of spring canola (Brassica napus L.) to boron application and sowing date, in Ramin Agriculture and Natural Resources University of Khuzestan in 2013-2014. The experiment was carried out as a split plots design in basis of RCBD with three replications. Planting dates (18 November, 3 December, 17 December and 30 December) and boron application treatments (control, 10 kg B.ha-1 incorporated with soil, boron spraying at 6 leaf stage and budding stages) were investigated as main and sub plots, respectively. Planting dates and boron application had significant effects on morphological traits, yield and quality of canola. The interaction effect of sowing date and boron on grain number per siliquie was significant. Late planting caused to significant decreased yield and its components. However, boron application incorporated with soil caused to compensate the negative effect of late planting. Generally, the highest grain yield (4579.7 kg.ha-1) was obtained from sowing at 18 November and 10 kg boron.ha-1 incorporated with soil, and lowest grain yield was obtained from planting at 30 December and without boron application. Delayed planting result in lowering morphological traits including plant height and branching. Delayed planting also caused by decreased grain oil and leaf N percentage, and increased grain N percentage. Boron application caused by significant plant boron content, but had no significant on grain oil ad N, and leaf N content. Also, boron application, in the experiment had no significant effect on alleviation of yield loss due to delayed canola sowing.