Removal of early fruit branches triggered regulations in senescence, boll attributes and yield of Bt cotton genotypes

Premature senescence, unopened and rotted bolls are the primary constrictions hampering the accomplishment of yield potential in Bt cotton. An experiment was conducted with the objectives to delay senescence, enhance boll opening and reduce the boll rotting. The experiment was conducted at two randomly selected sites of University of Agriculture Faisalabad, Pakistan, during 2015 and repeated in 2016. Each experiment was laid out in randomised complete block design with two by two factorial arrangement structure and replicated five times. Treatments were comprised of R-0 = no fruit removal; R-1 = removal of early fruit branches (REFB) and two genotypes, viz. V-1 = FH-142 and V-2 = MNH-886. Genotypes were selected on the basis of abiotic stress tolerance (FH-142) and susceptibility (MNH-886). Nodes above cracked bolls, monopodial branches, opened bolls per plant and seed cotton yield were enhanced by 23, 12, 13 and 17%, respectively, under the influence of REFB over no fruit branch removal, while the REFB-mediated decrease in boll rotting was 27%. Moreover, the response of MNH-886 was more remarkable than FH-142 for all studied variables. Conclusively, REFB increased the number of nodes above a cracked boll, monopodial branches, opened bolls per plant and seed cotton yield while decreased rotted bolls per plant in both genotypes.