Effects of ethephon, thidiazuron and their mixture on defoliation and ruit dehiscence in cotton

The defoliation and fruit dehiscence of cotton plants were evaluated by applications of Ethephon (rates: 0.96, 1.44 and 1.92kg/ha). Thidiazuron (0.075kg/ha) and the mixture of both Ethephon plus Thidiazuron (0.48 + 0.05, 0.96 + 0.05, and 1.44 + 0.05kg/ha, respectively). The mixture of the products was done in the sprayer tank. Observations of the cotton plants were carried out at seven and fourteen days after application of the products. Except for the application of Ethephon at the rate of 0.96kg/ha, it was observed that the three treatments were effective in promoting cotton defoliation. It was also verified that Ethephon at the rates of 1.44kg/ha accelerated fruit dehiscence while Thidiazuron did not. Antagonic action of the products was observed when applied in mixture. The isolated application of the products or the mixture had no effect on cotton yield.

cotton; Ethephon; Thidiazuron; defoliation and fruit dehiscence

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