EFFECT OF PLANTING DATES AND RATES OF NITROGEN AND POTASSIUM FERTILIZATION ON GROWTH AND PRODUCTIVITY OF GIZA 96 COTTON VARIETY

Abstract

Two field experiments were conducted at Sakha Agricultural Research Station at Kafr El-Sheikh Governorate, Egypt, during the growing seasons of 2018 and 2019 to study the effect of planting dates and rates of nitrogen and potassium fertilization on growth and productivity of Giza 96 cotton variety to preparing the optimal agricultural recommendation for it. The experiment design was a split plot with four replications. The main plots had two planting dates (Early at 15th April and Late at 15th May) and the sub plots had four rates of nitrogen and potassium fertilization (125% from the recommended dose for nitrogen (N) + potassium (K), 100 % N + K, 75% N + K, 50% N + K). (The recommended dose 60kg Nitrogen/fed. + 24 kg Potassium/fed.) The most important results obtained could be summarized as follows: Planting dates had a significant effect on growth, yield and its components and fiber properties. Early planting date significantly increased No. of fruiting branches /plant, No. of open bolls /plant, boll weight, seed cotton yield/fed. and gave good fiber properties. The rates of nitrogen and potassium fertilization had significant effect on growth traits, yield and yield components while did not exhibit any significant effect on fiber properties. The rate 100% N+K (60 kg N+24kg K) significantly increased No. of fruiting branches /plant, No. of open bolls /plant, boll weight, seed index and seed cotton yield/fed. The interaction between planting dates and rates of nitrogen and potassium fertilization had significant effect on growth, yield and its components while did not exhibit any significant effect on lint % and fiber properties. Generally, early planting in combination with the rate100% N+K (60 kg N+24kg K) significantly increased number of fruiting branches /plant, number of open bolls /plant, boll weight, seed index and seed cotton yield/fed and gave high productivity of Egyptian cotton variety Giza 96.