Effect of Foliar Application of Zinc on Leaf Expanse, Dry Matter Accumulation and Its Correlation with Grain Yield in Wheat

Wheat (Triticum aestivum L.) is a vital staple crop essential for global food security, especially in developing countries. This study investigates the impact of foliar zinc (Zn) application on leaf expanse, dry matter accumulation, and their correlation with grain yield in wheat. Conducted over two cropping seasons (2019-20 and 2020-21) at the N.E. Borlaug Crop Research Centre, GBPUA&T, Pantnagar, India, the experiment used a split plot design with five Zn sulphate concentrations (0, 0.25, 0.5, 0.75, and 1% ZnSO4·7H2O) and three spray frequencies (one, two, and three sprays). Results indicated that foliar Zn application significantly increased the Leaf Area Index (LAI), flag leaf length, and width. The highest LAI (4.69) was achieved with three sprays of 1702.5 ppm Zn, a 77% increase over the control. Similarly, flag leaf length and width increased by up to 42.8% and 41.5%, respectively. Zn application also enhanced dry matter accumulation, with the highest increase (50%) observed with two sprays of 2270 ppm Zn at maximum tillering. At the flowering stage, dry matter increased significantly, with the highest observed at one spray of 2270 ppm Zn. Grain yield improved significantly with Zn application, peaking at a 16.7% increase with 1702.5 ppm Zn. A positive correlation was found between Zn concentration, LAI, flag leaf dimensions, dry matter accumulation, and grain yield, indicating that foliar Zn application not only enhances grain yield directly but also improves overall plant growth characteristics. Future research should explore the long-term effects of foliar Zn application on soil health and nutrient cycling.