The effects of growth phytoregulators and pruning on the cotton crop were studied in ten field experiments. The phytoregulators used were: chlorocholine chloride, applied on dose of 50 g/ha; chlormequat chloride 100 g/ha, and mepiquat chloride, applied on dose of 100 g/ha. The pruning was done handly and individually by plant, at the same period of the application of the phytoregulators by 60-70 days after the plant emergence. The statistical delineament used was the randomized complete block design, with five treatments and six replications. The variety used was the IAC 19. Two groups of tests were done for the evaluation of yield and plant height results, one with a bigger development and another one with a smaller development, that is: plants of check plots with a height above and below 100 cm, respectively. The others agronomic and technological fiber characteristics were analyzed in an only group. For plants with the biggest development there was, on average, an increase in height of 16.3 and 8.4%, respectively, for the pruning treatment and for application of the phytoregulators. The application of the phytoregulator provided, on average, a reduction of 12.1% in the height of plants. In the other hand on average the practice of the pruning reduced in 20.8% the height of the plants, on average. The use of phytoregulators indistinctly, provided boll and seed weight increases, while with the practice of pruning, this effect was not significant. The application of chlormequat resulted in a lower percentage of fiber than the mepiquat chloride.
cotton; Gossypium hirsutum L.; chlorocholine chloride; chlormequat chloride; mepiquat chloride; growth phytoregulator; pruning; productivity and plant height