Effect of Spray Groth Regulators on Yield and Fiber Qulity in Egyptian cotton

Abstract

Field experiments were conducted in Sakha Station, Cotton Research Institute Agricultural Research Center, during 2017 and 2018 seasons, to investigate the impact of spraying some plant growth regulators (PGRs) on the yield and quality fiber of Egyptian cotton (G.barbadense) verities (G93 extra-long staple and G94, G97 long staple). A split split plot design in randomized complete blocks arrangement with four replicates was used in this study. The first factor verities occupied the main plots while the (PGRs) occupied the sub plots with three types Indol acetic acid (IAA), Gibberellic acid (GA₃) andMepiquat Chloride (MC).the third factor concentration was distnibuted randomly in the sub – sub plots as IAA (0/50/100/150),GA₃ (0/100/200/300ppm)and MC (0/50/100/150ppm).all the factors showed significance in both season .The results demonstrate that proper PGR rates aimed at optimizing cotton yield and quality were varied across varieties and growth hormones. Application of PGRs (except pix) had significant positive effects on the plant height , number of sympodia , average number of open bolls, boll weight andseed cotton yield/fedaan,. Fiber quality traits had little effects by PGRs types and doses; however UHML and micronaire readings were more effective for PGRs treatments.