EFFECTS OF POTASSIUM FERTILIZER APPLICATION TIMING ON ABOVEGROUND BIOMASS ACCUMULATION, NUTRIENTS UPTAKE AND COTTON YIELD

A 3-yr field experiment to study the efficiency of potassium fertilizer application timing on cotton aboveground biomass, potassium uptake and seed cotton yields was conducted in the old irrigated typical sierozem soils of the Tashkent region, Uzbekistan. Split application of K100 kg ha-1 before soil plowing in autumn (K50 kg ha-1 ) and at squaring stage (K50 kg ha-1 ) of the cotton growth raised the AGB by 7 %, the plant potassium uptake by 18-20 % and the seed-lint yield by 11 % compared to the control treatment with no K-fertilizer application.