Soil and Foliar Zinc Regulate Phenology, Canopy Development and Biomass Partitioning of Bread Wheat under Semi-Arid Conditions

Abstract

In many alkaline and calcareous soils zinc deficiency is a limiting factor for crop growth, but the relative importance of soil rate, foliar concentration and spray timing to wheat growth dynamics cannot be differentiated. The field experiment was carried out at Agronomy Research Farm, The University of Agriculture, Peshawar, Pakistan in winter season 2021-2022. The experimental design was 3 x 3 x 2 factorial randomized complete block with three replications and included a booting x anthesis timing of foliar Zn application in addition to soil Zn levels (5, 10 and 15 kg ha-1) and foliar Zn (0.2, 0.4 and 0.6%), and an untreated control. The application rate of soil Zn was zinc sulphate at sowing. Increasing soil Zn from 5 to 15 kg ha-1 reduced days to booting from 87.3 to 82.6, days to anthesis from 131.0 to 125.6 and days to maturity from 165.5 to 160.8. The same increase raised plant height from 90.5 to 107.1 cm, leaf area from 101.4 to 110.4 cm2 tiller-1, spike density from 262.2 to 308.2 m-2, total dry weight at anthesis from 416.5 to 484.4 g m-2 and total dry weight at maturity from 443.9 to 512.1 g m-2. At 0.6%, foliar Zn produced greater biomass production and canopy traits compared to lower concentrations and foliar application at anthesis. The interactions among the factors were non-significant for all of the growth traits measured, which means that their effects were largely additive. The overall conclusion is that soil Zn at 15 kg ha-1 coupled with foliar treatment at booting stage is an effective growth management technique for WADAN–17 wheat under the conditions tested.