Enzyme Activity of Bt Cotton Grown Soils as Influenced by Bio-Fertilizers and Foliar Application of Nutrition

Abstract

A filed experiment was conducted during rainy season of 2014 to study the effect of bio-fertilizer and foliar application of macro nutrients (N, P and K) on enzyme activity at 60, 90 and 120 days after sowing. Enzyme activity was higher during the flowering period (60 days after sowing) and thereafter the activity decreased with the age of the crop, the lowest activity was recorded at final harvest. Consortia of microbes applied to soil + foliar application of 18:18:18 at 1.5 per cent recorded significantly higher enzyme activity viz., dehydrogenase (11.3 pg TPF g 1 day1), acid phosphatase (142.2 pg PNP released g'1 h 1), alkaline phosphatase (101.3 pg PNP released g 1 h 1) and urease (95.3 pg NHy g 1 2 h 1) over other treatments at 60 DAS Significantly higher seed cotton yield also recorded with microbial consortia + foliar application of 18:18:18 at 1.5 per cent (1670 kg h a 1) over other treatments and the control (1004 kg h a 1). This study concludes that, soil application of the bio-fertilizers increases tested enzyme activity during the flowering in rain-fed situations and decreases with the age of the crop.