Agronomic Biofortification with Zinc and Iron for the Improvement of Wheat Phenology and Yield

Abstract

| Both zinc (Zn) and iron (Fe) are involved in the biochemical and physiological processes of the wheat plant. Low Zn and Fe contents in soil and/or their low availabilities for plant uptake not only affect the final yield but also decrease their harvestable levels in the wheat grains. The research trials were conducted for two consecutive years (2016-17 and 2017-18) on the foliar supply of Zn and Fe to wheat at different growth stages in the Agronomy Research Farm, the University of Agriculture, Peshawar - Pakistan. Four Zn levels (0, 1, 2, and 3 kg ha-1) and four Fe levels (0, 2, 4, and 6 kg ha-1) at three growth stages (i.e. foliar application of full dosage at the tillering stage, full dosage at the booting stage and their respective half dosages at the tillering stage + half at the booting stage) along with one unsprayed check were used in the experiment. All the treatments’ combinations and a control {(4 x 4 x 3) +1} were laid out in a randomized complete block design having three replications. The plot size was 12 m2 accommodating ten rows. The recommended wheat cultivar ‘Pirsabaq 2013’ was sown by using 120 kg ha-1 seed rate. Nitrogen at the rate of 120 kg ha-1 was applied in two splits from urea. Similarly, 90 kg ha-1 phosphorus was applied from DAP at the time of sowing. Analysis of variance showed that sole foliar Zn application at 3 kg ha-1 significantly improved the flag leaf area (36.9 cm2) and leaf area tiller-1 (97.2 cm2). While more spike m-2 (248), maximum grains spike-1 (47.2), spike length (13.1 cm), and thousand grains weight (42.9 g) were observed with foliar application of 2 kg ha-1 Zn. Significantly maximum leaf area tiller-1 (96.4 m2), flag leaf area (36.2 cm2), spike m-2 (253), grains spike-1 (46.9), spike length (12.9 cm) and thousand grains weight (43 g) were found best with the application of 4 kg ha-1 Fe. In case of application stages, more leaf area per tiller (95.9 cm2) and flag leaf area (36 cm2) were observed with both the application of Zn and Fe when applied 100 % at tillering stage. Similarly, more spike-2 (250.9), maximum grain spike-1 (46.3), spike length (12.7 cm), and thousand grains weight (42.6 g) were noted with the split foliar application of both Zn and Fe. It can be concluded from the experiment that application of both foliar Zn and Fe enhanced the phenological development and yield component of wheat crop. Similarly, foliar application of full dosage at tillering stage also hastened the phenological parameters of wheat crop, therefore recommended for the wheat crop cultivation in the locality of Peshawar.