Studying norms of application of defoliant UzDaF in S-8286 type of cotton depending on fertilizer conditions, average soil moisture content of 7-8 meters in the meadow-gray and subsoil waters of Samarkand region. When analyzing the data obtained from the background, we observed that when the irrigation regime of cotton was 65-65-60% compared to the ChDNS, the number of green leaves and deciduous vegetation branches. The experiment also investigated the effect of defoliant shedding of cotton leaf on plant development