Effect of different levels and frequency of potassium application on yield and quality of Bt cotton hybrid

An experiment was conducted at Cotton Research Sub-Station, Navsari Agricultural University, Achhalia (Gujarat) for six years (2017-18 to 2022-23). Eight treatment combinations comprising of two potash levels (60 and 120 kg K2Oha-1) and four frequency of application Every year (full dose as basal), Every alternate year (full dose as basal), Every year (two equal splits) and Every alternate year (two equal splits) were compared with two treatments viz., No application or spray of K and Spray of Banana pseudo-stem enriched sap @ 3% with three sprays at squaring, flowering and boll formation stage in Factorial Randomized Block Design with three replications. The results revealed that, application of potassium fertilizer every year @ 120 kgha-1 recorded significant higher seed cotton yield (2107 kgha-1) as compared to 60 kg K2Oha-1, control-1 and control-2. Treatment of 120 kg K2Oha-1 also recorded higher net income (46737 Rsha-1) with BCR of 1.49. Application of potassium fertilizer every alternate year, values of seed cotton yield and net income were higher than those of alternate year K application. Conclusion of the above results may be that for obtaining higher seed cotton yield and net return from Bt cotton hybrid grown on potash deficient soil under irrigated condition of South Gujarat should apply 120 kg K2Oha-1 as basal dose in addition to recommended fertilizer dose of nitrogen (240 kg Nha-1) and phosphorus (40 kg P2O5ha-1).