Improving the performance of Bt-cotton under heat stress by foliar application of selenium.

Heat stress at reproductive stages of cotton is a leading encumbrance to accomplish yield potential. An experiment was conducted to alleviate adversities of terminal heat stress on cotton. Experiment was conducted at University of Agriculture Faisalabad, Pakistan during 2013 and repeated in 2014 using Randomized Complete Block Design (RCBD) with split arrangement. Treatments were comprised of heat stress in main plots, viz., H₀ = no heat imposition, H₁ = heat imposition at squaring, and H₂ = heat imposition at flowering. Selenium was foliar applied in split plot, viz., Se₀ = 0, Se₅₀ = 50, Se₁₀₀ = 100, and Se₁₅₀ = 150 mg L⁻¹. Cell membrane thermostability, soluble proteins, and total phenolics were reduced significantly under heat stress leading to reduced cotton yield and related components. Maximum membrane thermostability, total phenolics, soluble proteins, opened bolls, boll weight, sympodial branches, and seed cotton yield were recorded with the application 150 mg Se L⁻¹. [ABSTRACT FROM AUTHOR]