Effects of Shoot Apex Removal on Growth and Yield Attributes of Cotton

Abstract

The current study was designed to investigate the effect of shoot apex removal on the growth and yield attributes of the cotton crop. A field experiment was conducted in the cotton-growing season (2020-2021) at Muzaffargarh, district of South Punjab. The field trial was comprised of two acres of land where one acre of land was considered as treatment (cotton plants with shoot apex removal) and the other acre of land served as a control plot (cotton plants without shoot apex removal). The data were collected fortnightly (1st, 2nd, 3rd, 4th and 5th times) from the randomly selected cotton plants (n=50) from the treated and control plot after fifteen days of treatment (shoot apex removal). The data were comprised of vegetative parameters (i.e., plant height, no. of nodes and leaves), reproductive parameters (i.e., no. of squares, flowers, immature/mature bolls, the opening of bolls and boll weight) and cotton fiber quality parameters [i.e., fiber length, strength, finesse and GOT (ginning outturn)]. Descriptive analysis was employed on all data recorded through an independent two-sample t-test to evaluate the positive effect of shoot apex removal in cotton production. Our results indicated that after removing the top shoot of the cotton plants, greater effects had started to occur in the treated plants such as vegetative growth had become significantly (at p≤0.001) slow down and reproductive growth considerably (at p≤0.01) enhanced. Besides, removal of the shoot apex in cotton plants has developed resistance against the sucking pest i.e., pink bollworm infestation significantly reduced by 50% and whitefly population has lessened by 11%. The results also indicated that this treatment significantly augmented (at p≤0.01) the boll weight by 12%, as well as improved the cotton fiber length, strength and fineness by 7% as compared to the normal cotton plant. It was concluded that shoot apex removal caused cotton plants to produce numerous lateral shoots to develop more branches to carry more cotton bolls on them eventually significantly enhancing the cotton yield by 13% (18 monds acre-1) as compared to the control plot. It can be suggested that the practical implementation of removing the shoot apex of the cotton plant would act as a promising technique to enhance the cotton yield.