INFLUENCE OF IRRIGATION REGIME AND FERTILIZER NORMS ON THE YIELD OF "ANDIJAN-36", S-6524 VARIETIES OF AVERAGE FIBER COTTON UNDER THE CONDITION OF TYPICAL SEEDIC SOILSS

Abstract

On the condition of typical sierozem soils of Tashkent province the research were conducted to study the optimal irrigation and fertilizer application scheduling of Andijan-36 and S-6541 cotton varieties. The paper presents materials that on sierozem soils, it was recommended to irrigate cotton variety Andijan-36 with irrigation scheduling 65-65-60% Fc, irrigation scheme 1-2(3)-1(2) with 4 to 6 irrigation events, seasonal irrigation norm were 4450 to 5890 m3 ha-1, on cotton variety C-6541 with irrigation scheduling 70-70-60% Fc, irrigation scheme 1-3(4)-1(2) with 5 to 7 irrigation events, seasonal irrigation norm totaled 4730 to 5990 m3 ha-1 and in both cotton varieties optimal fertilizer application rate was N190 Р133 К95 kg ha-1. It was recommended to begin the irrigation events at the end of May, in the first decade of June months, the last irrigation events was considered to finish at the first 5 and 10 days of September months, irrigation duration till flowering 20 to 24 hours, flowering – yield accumulation 26 to 35 hours, maturation – boll opening phase 21 to 31 hours, irrigation intervals 12 to 28 days were recommended.