Abstract
Dietary zinc (Zn) and iron (Fe) deficiency is a major nutritional disorder for the majority people of Bangladesh who heavily subsist on cereals, chiefly rice and wheat. The present study was undertaken with a major objective to enhance Zn and Fe concentrations of wheat through use of selected varieties and application of respective fertilizers. To achieve the intended objective, field experiments were conducted at Bangladesh Agricultural University (BAU) farm, Mymensingh (AEZ 9, non-calcareous soil) and at BINA substation, Ishwardi (AEZ 11, calcareous soil) for two consecutive wheat seasons (2014-15 and 2015-16). In the field trials, 10 varieties and 15 advanced lines of wheat were tested under 3 treatments: control, Zn and Zn + Fe; the Zn rate being 3 kg ha-1 and Fe rate 4 kg ha-1 supplied through ZnSO4.7H2O and FeSO4.7H2O, respectively. Other nutrients viz. N, P, K, S and B were used at a recommended rate to all plots. After harvest, yield and yield contributing characters were recorded. The grain samples from every plot were analyzed for Zn, Fe and N concentrations. Several varieties and breeding lines of wheat were found to have greater ability to uptake and accumulate Zn and Fe in grain, with a further possibility to have enhanced grain Zn and Fe concentrations through their fertilization. Varieties BARI Gom25, 27, 28 & 29 and breeding lines Vijay, HPYT-5, 15 & 21 and BL-1883 have been identified as Zn enriched wheat varieties (24 - 30 ug g1). The grain Zn concentration of wheat genotypes was further increased by 4-8 μg g1 due to Zn fertilization. Concerning Fe enriched wheat genotypes (24 - 30 μg g1), five varieties viz. Shatabdi, Prodip, BARI Gom25 & 28 and Sufi, and four lines such as HPYT-12, BL-1883, BL-1040 and Fery-60 have been identified. The grain Fe concentration of wheat genotypes increased when Fe was added, the increment being 6-12 μg g1. The protein content of wheat also increased due to Zn application showing a positive relationship between Zn and N. The grain yield of wheat was increased by 3.8 - 25.7% due to Zn application over the varieties and locations. There was no effect of Fe supplement on grain yield of the crop. Overall results indicate that the breeding together with agronomic approach (fertilization) extends a good opportunity of improving Zn and Fe levels in wheat grain, without incurring loss to wheat yield.