Studies on Terminal Heat Stress and its Mitigation on Seed Yield Quality and Storability in Wheat Triticum aestivum L

Abstract

A field experiment was conducted to study the efficacy of bio-stimulants in newlinemitigating terminal heat stress and also to evaluate the effect of bio-stimulants on newlinegrowth and yield in wheat in split-split plot design and replicated thrice. The experiment newlineconsisted of two dates of sowing i.e., 25th November (D1: normal sown), 20th December newline(D2: late sown) with two contrasting varieties, UAS-304 and HD-3090 and foliar spray newlinewith bio-stimulants such as T1 control (water), T2 salicylic acid (800 ppm), T3 salicylic newlineacid (400 ppm), and T4 thiourea (100 ppm) during anthesis stage. newlineResults showed that, seed yield was increased significantly and maximized (3.04 newlineand 2.76 kg plot-1 for UAS-304 and HD-3090 respectively) when the crop received newlinefoliar spray of salicylic acid (400 ppm) at anthesis stage over control. Variety, UAS-304 newlinehad performed better when it was sown on normal date of sowing whereas, newlinecomparatively the performance of HD-3090 was better percentage wise when it was newlinesown in second date of sowing. But, yield remained higher in UAS-304 it may be due to newlineits genotypic constitution with respect to geographical location. Application of biostimulants newlineshowed positive effect on plant height, length of spike, number of grains per newlinespike and grain yield whereas days to flowering, number of leaves per plant and newlineeffective number of tillers per plant remained unaffected. Late sown variety HD-3090 newlinehad higher germination percentage, shoot length, root length, seedling dry weight and newlinevigour index-I and II as compared to early sown variety UAS-304. Correlation newlinecoefficients among most of the traits were statistically significant. Seed yield was newlinepositively correlated with days to 50 per cent flowering, days to maturity, SPAD, grain newlinefilling duration, number of spikelets per spike, number of grain per spike, spike length, newlineseed set per cent and 1000-seed weight. Seeds harvested from both sowing conditions newlineduring 2021 were subjected to storage studies for one year with different packaging newlinematerials and zeolite beads and analyzed with FCRD