Vegetos

Abstract

A field experiment was conducted at the Experimental Area of Cotton Section, Department of Plant Breeding and Genetics, Punjab Agricultural University, Ludhiana in a randomized complete block design (factorial) to study the effect of growth regulators (ethrel and maleic hydrazide) on growth, yield attributes and seed cotton yield in two cotton hybrids FHH 141 (non Bt) and NCS 855 BGII (Bt). Results revealed that hybrids did not vary significantly in terms of seed cotton yield, plant height, sympods/plant, boll weight and boll number/plant. The growth regulators have shown the favorable effect on the retention of bolls and their opening. The maximum seed cotton yield was obtained with the foliar application of ethrel @ 45 μg/ml at square initiation (40 DAS) followed by application of maleic hydrazide (MH) @ 750 μg/ml at 80 DAS (23.03 q/ha) which was significantly higher than all other treatments except when ethrel was sprayed @ 45 μg/ml at square initiation (40 DAS) followed by MH 750 μg/ml at 95 DAS (21.49 q/ha). Higher seed cotton yield on account of growth regulator spray was chiefly because of higher number of bolls/plant (34.94), sympods/plant and plant height which enable the canopy suitable to avail the climatic effect favorably.