Exogenous Applied Zinc, Cytokinin and Gibberellic Acid Affecting Growth and Yield of Timely and Late Sown Wheat (Triticum aestivum L.)

Abstract

Background: Micronutrient deficiency especially of zinc (Zn) impacts wheat growth and yield under both timely sown and late sown conditions. The study investigated the effect of Zn, cytokinin and gibberellic acid (GA) on growth and yield of wheat crop. The design of experiment was split-split plot having three replications. Methods: The main plots were comprised of two varieties i.e., V1 (PBW 725) and V2 (PBW 752) which were divided into three subplots Zn0 (no Zn), Zn1 (62.5 kg/ha soil application of ZnSO4) and Zn2 (31.25 kg/ha Zn in soil+foliar spray of 0.5% of ZnSO4). The subplots were further divided into four sub-sub plots i.e., H0 (no hormone), H1 (10 ppm GA), H2 (10 ppm cytokinin) and H3 (5 ppm GA+5 ppm of cytokinin). Result: The results indicated that the combination of Zn2+H1 resulted in maximum height of plant, accumulation of dry matter and straw yield for both varieties. The reported increment for all three parameters was 8.3%, 15.4% and 18.9% for V1 and 10.1%, 14.9% and 17.4% for V2, respectively. However, for both V1 and V2 a combination of Zn2+H2 improved tiller count, leaf area index and ultimately grain yield. The increment for V1 was 24.4%, 15.2% and 17.1%, while for V2 was 30.1%, 17.2% and 19.3%, respectively. The maximum harvest index value was recorded for variety V2 under Zn2+H2. The correlation analysis showed that leaf area index, number of tillers and dry matter accumulation are strongly correlated with grain yield. In general, the study emphasized that soil+foliar application of Zn alongside 10 mg/L cytokinin was most prominent in improving growth and yield of both wheat varieties.