Effect of foliar and split application of potassium on seed cotton yield and fibre quality of American cotton (Gossypium hirsutum)

A field experiment was conducted at Ludhiana (30 degrees 56 N latitude, 75 degrees 52'E longitude) during rainy (kharif) of 2006-09 on a sandy loam soil low in organic carbon, available nitrogen and high in available phosphorus and potassium to study the effect of foliar and split application of potassium as a supplement to one time application of potassium on the growth, yield and fibre quality of American cotton (Gossypium hirsutum L.). The area is characterized by sub-tropical semi-arid type climate with hot summer and very cold winters. The highest mean seed cotton yield (2 612 kg/ha) was recorded with application of four sprays of 2% KNO(3) solution at weekly interval starting from flowering onwards and the lowest seed cotton yield (2 077 kg/ha) was recorded in control. The foliar and split application improves the 2.5% span length significantly as compared to control. The highest benefit: cost ratio (31.5) was obtained.in treatment where muriate of potash @ 50 kg/ha (30 kg K(2)O) was applied in four split doses and the lowest (1.72) was observed where four sprays of 3% KNO(3) were applied.