Enhancing translocation and remobilization of zinc in wheat by the application of plant growth regulators

A pot experiment was carried out to evaluate the impact of plant growth regulators (PGRs) on translocation and accumulation of zinc (Zn) in grains of four wheat varieties of varying Zn sensitivities. Different concentrations of two (gibberellic acid and cytokinin) PGRs viz., control, 10 ppm gibberellic acid (GA), 20 ppm gibberellic acid (GA), 10 ppm cytokinin (kinetin), 20 ppm cytokinin (kinetin), 10 ppm gibberellic acid (GA) + cytokinin (kinetin), 20 ppm gibberellic acid (GA) + cytokinin (kinetin) were applied under different Zn regimes (control), soil application of 5 mg Zn kg-1 soil and soil application of 5 mg Zn kg-1 soil + foliar applications of 0.5% ZnSO4.7H2O + 0.25% lime). Four contrasting wheat varieties i.e., UP262 & PBW175 (Zn inefficient), UP2628 & UP2554 (Zn efficient); were tested for enzyme activities, yield attributes and Zn content in various plant parts. Regarding influence of PGR levels, the maximum CA and SOD activities were recorded under 20 ppm GA and control respectively. The grain yield, straw yield and grain Zn content was found to be the maximum under 10 ppm GA+cytokinin, 20 ppm GA and 20 ppm cytokinin respectively. Among all the methods used, soil along with foliar spray (Zn S+F) was found to be the most effective in improving all the crop parameters. Among varieties, the efficient sets of varieties (UP2628 & UP2554) performed better than Zn inefficient varieties. The use of plant growth regulators along with efficient delivery method could enhance the transport and accumulation of Zn in grains of wheat.