Effect of Potassium and Zinc on Growth, Yield, Quality Parameters and Nutrient Uptake by Cotton

A field experiment was conducted during 2004-05 and 2005-06 on medium black calcareous soil (Typic Ustocrepts) with cotton (G-cot-hy-10) using 5 levels of K (0, 90, 120, 150 and 180 kg ha^-1) and 3 levels of ZnSO₄ (0, 25 and 50 kg ha^-1). The significantly higher seed cotton (2345 kg ha^-1) and stalk (3679 kg ha^-1) yield of cotton were recorded with K₁₂₀ and K₁₈₀ treatments, respectively. Whereas the highest seed cotton yield (2269 kg ha^-1) and stalk yield (3540 kg ha^-1) were recorded with application of ZnSO₄ @ 50 kg ha^-1. The plant height (138.1 cm), boll weight (20.4 g) and oil content (18.52 %) were observed significantly higher with the application of potassium @ 120,150 and 180 kg ha^-1, respectively. While, number of bolls per plant, ginning percentage and test weight did not influence by potassium application. Application of zinc did not influence quality parameters except boll weight. The maximum uptake of K and Zn by seed cotton as well as stalk yield was recorded under application of 120 kg K₂O and 50 kg ZnSO₄ ha^-1, respectively.