<p>The foreign Ento-Dephol showed high result with 30-40% of guza couses opened using 0.200 litres of defoliation for each hectare in view to defoliate cotton artificially. 7.0 litres of defoliation ensured better result compared to other alternatives. It is explained which defoliant is best used in opening of cotton buds. In the second stage of defoliation (50-60% when the cocoons <br /> opened), the effectiveness of used defoliants proved to be high, and the yield appeared excessive owing to high percentage of cocoon opening as compared to the first stage, in return to which the profitability had increased by 1.1-5.1%. Due to the fact that the cotton variety S-8290 ripens <br /> 10-15 days earlier than the cotton variety S-6775, the performance was high, however there was no difference in the amount of defoliants used, as there was no significant difference in the leaf blade of both types of cotton.</p>