Studies on drip fertigation on growth, yield and pest incidence of american cotton (Gossypium hirsutum L.) and desi cotton (Gossypium arborium L.) on sandy loam soil

Abstract

A field experiment was conducted to find out optimum fertigation schedule through drip in American and desi cotton for three consecutive years on sandy loam soil of Sriganganagar. The application of 100 per cent recommended dose of N (150 kg N/ha) and K (20 kg K2O/ha) in six equal splits at an interval of 15 days to American cotton gave significantly highest seed cotton yield. This treatment gave 49.8 per cent higher seed cotton yield over recommended practice. It gave the maximum number of bolls/plant, boll weight and seed index. The maximum water use efficiency was also recorded with this treatment. It gave higher fertilizer use efficiency in comparison to recommended practice. The average whitefly/leaf and the percentage infestation of spotted bollworm were significantly less in fertigation treatments in comparison to recommended practice. Fertigation improved the quality of lint. In desi cotton, drip irrigation at 0.8 and 1.0 ETc did not differ significantly in seed cotton yield, boll weight and plant population. The average effect of drip irrigation was found significantly superior over surface irrigation in terms of yield attributes, seed cotton yield and water use efficiency. Drip irrigation increased seed cotton yield by 27.5 per cent over the recommended practice. The application of 75 per cent recommended dose of N gave at par yield with 100 and 125 per cent recommended dose. The application of nitrogen in six equal splits at an interval of 15 days was found at par with 9 equal splits at an interval of 10 days. The maximum water use efficiency (3.44 kg/ha mm) was recorded with drip irrigation at 0.8 ETc. The incidence of whitefly and per cent infestation of spotted bollworm was significantly less in drip irrigated treatments in comparison to recommended practice.