Macro and Micronutrient Driven Improvement in Growth, Yield and Quality of Kharif Sunflower (Helianthus annuus L.)

Abstract

Sunflower growth, yield and quality are significantly influenced by plant nutrition. The significance of micronutrients is frequently disregarded, despite the regular application of macronutrients like potassium, phosphorus and nitrogen. A lack of these essential elements leads to reduced yield and poorer oil quality. Among the essential micronutrients, zinc (Zn), boron (B), iron (Fe), manganese (Mn), copper (Cu), and molybdenum (Mo) are particularly important for sunflower growth. Therefore, the present investigation aims to study the response of sunflower to different micronutrients with respect to growth, yield, quality parameters and economics. The field experiment was laid out in randomized block design during kharif season of 2022 at Experimental Farm, Agronomy Section, Oilseeds Research Station, Latur. The treatments were T1 - Control, T2 - RDF (90:45:45 kg N:P:K ha-1), T3 - RDF + ZnSO4 @ 20 kg ha-1, T4 - RDF + FeSO4 @ 20 kg ha-1, T5 - RDF + Borax @ 2 kg ha-1, T6 - RDF + ZnSO4 @ 20 kg ha-1 + FeSO4 @ 20 kg ha-1 + Borax @ 2 kg ha-1, T7 - RDF + Multimicronutrient Grade-1 @ 25 kg ha-1, T8 - RDF + Multimicronutrient Grade-2 @ 0.2% at 20 DAS, T9 - RDF + Multimicronutrient Grade-1 @ 25 kg ha-1 + Multimicronutrient Grade-2 @ 0.2% at 20 DAS. The results showed that application of RDF + ZnSO4 @ 20 kg ha-1 + FeSO4 @ 20 kg ha-1 + Borax @ 2 kg ha-1 (T6) recorded highest growth indices viz. Absolute Growth Rate (AGR) expressed on a plant height and dry matter basis, Relative growth rate and Leaf area index. It also reported significantly highest “132% higher seed yield than control” (1791 vs 771 kg ha⁻¹) test weight, seed yield and oil content and oil yield. The benefit–cost (B:C) ratio ranged from 1.46 in the control to 2.66 under T6, indicating better economic viability of micronutrient supplementation. Treatments receiving combined or individual micronutrients in conjunction with RDF recorded higher B:C ratios than RDF alone, demonstrating improved profitability. Overall, the results clearly indicate that combined application of RDF with Zn, Fe, and B (T6) was the most economically profitable treatment, owing to higher seed yield and monetary returns despite a marginal increase in cost of cultivation. Similar trends were also recorded in the economical parameters of statistical data. Overall, the study concludes that balanced fertilization with micronutrients enhances growth, productivity, quality and profitability of sunflower.