Response of Micronutrients on Growth and Yield of Wheat Under Late Seeding Heat Stress Condition

Abstract

Cereal and its derived products have a crucial importance worldwide. Baking industries extensively use wheat flour and also important source of various nutrient components. Therefore, this investigation is intended to study and determine growth, yield and physiochemical properties of wheat varieties. Heat stress is a worldwide problem, constraining global crop production seriously. The experiment was conducted to study the response of micronutrients on growth and yield of wheat under late seeding heat stress condition at the Regional Wheat Research Centre (RWRC), Rajshahi during the Rabi season from November 2015 to April 2016 and November 2017 to April 2018. A split-split plot design was adopted with three replications. Two wheat varieties BARI Gom 26 and BARI Gom 28 were used as test crop, three seeding dates one was optimum and other two were late condition (25th November, 10th December and 25th December) were applied as heat stress condition and four micro-nutrients levels (absolute control, 1.25 kg B ha-1, 5.30 kg Zn ha-1 and 1.25 kg B ha-1 + 5.30 kg Zn ha-1) were used to conduct this experiment. The study revealed that the crop sown on the 25th November gave most of the highest growth, yield components, yield and finally produced the highest nutrient parameters from both the years. Heat stress late sown condition caused significant reductions in growth and yield of both wheat varieties. It was evident from the results that micro-nutrients have significant effect on growth parameters. Total Dry Matter (TDM) increased with the increase of age of plant. Leaf Area Index (LAI) increased slowly at the early stage of crop growth then rapidly increased at vegetative stage and then it declines. Crop Growth Rate (CGR) and Net-Assimilation Rate (NAR) also had the similar results. Relative Growth Rate (RGR) was also found maximum at crown root initiation to tillering stage and then declined with increasing in plant growth stage. Leaf Area Ratio (LAR) declined in the successive growth stage and it reached the lowest at maturity stage in both the years. However, the highest grain yield was obtained from the treatment M3 (1.25 kg B ha-1 + 5.30 kg Zn ha-1). The results revealed that BARI Gom 28 produced the highest grain yield with M3 (1.25 kg B ha-1 + 5.30 kg Zn ha-1). In contrast, the shortest plant and minimum grain yield being recorded from the control treatment. In comparison among of two wheat varieties with the response of different levels of micro-nutrients under late seeding heat stress condition demonstrated that BARI Gom 28 gave the highest performance (yield 4.99 and 4.63 t ha-1) than BARI Gom 26 (yield 2.40 and 1.60 t ha-1) in both the two years among most of the parameters. The results of the experiment also revealed the bio-chemical composition of wheat grain. Each sample has been counted in 100 g of grain. Heat stress also decreased all the nutrient parameters except protein and ash content. The BARI Gom 28 had the highest amount of protein, carbohydrate, starch, pH, ash, Ca, and P with the treatment M3 (1.25 kg B ha-1 + 5.30 kg Zn ha-1) whereas BARI Gom 26 had highest TSS, Fe and Zn. Results showed that both the wheat variety could be used to make various type of brand wheat flour for baking products. The overall results indicate that micronutrient levels M3 (1.25 kg B ha-1 + 5.30 kg Zn ha-1) was better in variety BARI Gom 28 than BARI Gom 26 for growth, yield and yield contributing characters as well as nutrient parameters under late sown heat stress tolerance in AEZ-11. The data obtained from this comparative study will help in the development of suitable growth, yield and nutrient profile of wheat grain under late sown heat stress condition.