The study of effect of zinc and boron foliar application on yield, yield components, seed oil and protein content and growth indices of rapeseed (Brassica napus L.) in Khorramabad climatic conditions

In order to study the effects of micronutrients zinc (Zn) and boron (B) foliar application on seed yield, yield components, seed oil and protein content and growth indices of canola (Brassica napus cv okapi), a field experiment was conducted during 2008 growing season. The experiment was a factorial with sixteen treatments and three replications on the basis of a completely randomized block design (CRBD). Four levels (0, 5, 10 and 15 Kg.ha-1) of zinc sulphate (22% Zn) at 1500 mg.L -1 and four levels (0, 5, 10 and 15 Kg.ha-1) of boric acid (17/5% B) at 3000 mg.L ‌‌‌‌-1 was applied‌. Sampling was carried out at the rossette stage and at the beginning of the vegetative growth to the end of the plant growth (every 14 day). Analysis of variance showed that the main effects of Zn and B on seed yield, pods/plant and seed/pod, total dry matter and seed oil and protein content was significant, however, just the main effect of Zn was significant on plant height (P>0.05). The effect of these elements on the weight of 1000 kernel was not significant. The seed maximum yield was equal to 3957 Kg.ha-1 using 15 Kg.ha-1 zinc sulphate and 10 Kg.ha-1 boric acid. With the foliar application of Zn and B, crop growth rates (CGR), total dry matter (TDM) and leaf area index (LAI) were increased.