Application of defoliants alters leaf growth and gas exchange parameters for cotton defoliation

The goal of the current study was to determine how different chemical defoliants and application timing affected defoliation in cotton variety CO 17. The studies were conducted using a split-plot design with three applications at three different times as the main plot and seven defoliants as the subplot. Thidiazuron + Diuron (0.03%) defoliant reduced the gas exchange parameters, photosynthetic rate, transpiration rate and stomatal conductance by reducing plant growth parameters, leaf area, leaf area index, specific leaf weight which significantly increased the defoliation percentage. The negative correlation of cotton growth and gas exchange parameters with defoliation percentage was observed in correlation studies. In conclusion, Thidiazuron + Diuron (0.03%) defoliant was found to be superior in action for improving leaf defoliation and its associated parameters. And also it may be a cost-effective cotton defoliant for aiding the mechanical picking of cotton bolls.