Response of graded levels of soil and foliar applied potassium fertilizers on growth and yield of Bt cotton in Vertisol

Effect of potassium on yield and nitrogen on vegetative growth tends to be more critical when deficiency is expected in a field. Foliar applications of potassium may be used to supplement soil applications to maximize yields and improve quality of cotton. A cotton hybrid MRC-7351 was sown at Main Agricultural Research Station, UAS, Dharwad in Vertisol under rainfed condition with protective irrigation to check the effect of potassium on growth and yield of Bt cotton during 2012–13 and 2013–14. The crop was sown in a randomized complete block design and was replicated thrice. Pooled data of two years indicated that the best results were found when cotton plants were treated with 100: 50: 75 (RDNP+150% RDK)+2% KNO3 foliar spray at 70, 90 and 110 DAS (T8). Moreover, this treatment also produced significantly higher yield (2689 kg/ha).