Interactive Effects of Foliar Application of Zinc, Iron and Nitrogen on Productivity and Nutritional Quality of Indian Mustard (Brassica juncea L.)

Abstract

Indian mustard (Brassica juncea L.) is an important winter oilseed crop in India. It acts as a promising species for the extraction of Zn and Fe under nutrient-deficit conditions. Therefore, this study planned to determine the impact of nutritional supplementation (Zn, Fe and urea) on the productivity and nutritional quality of Indian mustard. In the experiment, different combinations of recommended dose of fertilizer (RDF) with 0.5% FeSO4·7H2O, 0.5% ZnSO4·7H2O and 1% urea at 45 and 60 days after sowing (DAS) were applied to Indian mustard. Foliar application of micronutrients along with urea enhanced the productivity and quality of the crop. Among different treatments, the foliar application of 0.5% FeSO4·7H2O + 0.5% ZnSO4·7H2O + 1% urea (FZU) at 45 and 60 DAS resulted in the maximum increase in grain (27.8%) and stover (34.47%) yield, which was statistically at par with the treatment 0.5% FeSO4·7H2O + 0.5% ZnSO4·7H2O at 45 and 60 DAS (FZ). A similar trend was observed for Zn concentration in grain and stover, as well as Fe concentration in stover. However, the Fe concentration in grain was at maximum with treatment FZU, and the results were significantly higher compared with the treatment FZ. Treatment FZU also resulted in a maximum increase in Zn and Fe uptake in grain (54.7% and 34.3%, respectively) and stover (110.5% and 46.1%, respectively), which was statistically at par with treatment FZ. Physiological efficiencies of Zn (11,838.33) and Fe (3575.887) were highest when only urea was applied along with RDF, whereas the apparent recovery efficiency of Zn and Fe was highest in treatment FZU. Overall, it is concluded that combined foliar application of, 0.5% FeSO4·7H2O + 0.5% ZnSO4·7H2O + 1% urea at 45 and 60 DAS along with RDF was found to be most effective to enhance yield, concentration and uptake of Zn and Fe in Indian mustard.