Effect of Foliar Application of Boron and Zinc on Yield and Some Qualitative Characteristics of Two Rapeseed (Brassica napus L.) Cultivars

In order to study the effect of foliar application of boron and zinc on yield and some qualitative characteristics of two rapeseed (Brassica napus L.) cultivars, a factorial experiment was carried out based on RCBD with 18 treatments and 3 replicates during 2005-2006 at Zanjan Agricultural Research Station. Factors of the experiment were: spraying of in 3 levels including Zn0 (without spraying), Zn1 (spraying with 3 g ZnSO4/L), Zn2 (spraying with 6 g ZnSO4/L) and H3BO3 spraying including B0 (without spraying), B1 (spraying with 2 g H3BO3/L), B3 (spraying with 4 g H3BO3/L) and the cultivars were V1 (SLM046) and V2 (Talayeh). Zn and B foliar applications were done in two plant phenological stages (early stemming and flowering). During the growth season common agronomic practices were followed and grain yield and concentration of oil, protein, Fe, Mn, Zn, Cu and B of rapeseed grains were measured at harvesting time. Results showed significant difference between the treatments, so maximum grain yield of 4180 kg/ha was obtained from Zn0B1 in V1 cultivar. Concomitant application of Zn and B led to increase in their concentrations in the grain that is important from rapeseed fortification view of point. Therefore, regarding to beneficial effects of B on grain yield and joint application of B and Zn on the seed quality simultaneous spraying of boric acid and Zn sulphate with 2 g /L and 3 g /L respectively in early stemming and flowering stages may be recommended for the study area and the similar regions.