Growth, yield, water productivity and economics of okra (Abelmoschus esculentus L.) in response to gravity drip irrigation under mulch and without-mulch conditions

Optimization of water by the drip irrigation system and soil water conservation through appropriate mulching is a prerequisite for sustainable crop production in water resource-scarce areas. A three seasons of field experiment was conducted to investigate the crop and water productivity of okra in relation to gravity drip irrigation use of mulch in combination with mulch under the environmental condition of the Indo-Gangetic plains of eastern India. Four levels of irrigation viz., surface irrigation at 1.0 IW/CPE (I1), drip irrigation at 0.6 (I2), 0.8 (I3) and 1.0 (I4) of crop evapotranspiration (ETc) and three mulches viz., no-mulch (M0), black polythene mulch (M1) and paddy straw mulch (M2) laid out in a split-plot design with three replications were investigated. Results showed that I3M1 produced the higher average growth, yield attributes, fruit yield (12.24 t ha ? 1), CWP, IWP, ECWP and EIWP and maximum economic returns, being almost identical to I4M1. Under severe water scarcity, I2M1 was an alternative. The highest BCR was accomplished in I4M0 followed by I3M0. Drip irrigation scheduling saved about 14-56% of water over surface irrigation, which could accommodate 11.1-48.6% of additional land area under the drip irrigation network. The optimal irrigation and ETarequirements were estimated at 86-136 mm and 142-168 mm, respectively for obtaining maximum yield (12.1-12.3 t ha- 1). The water-yield production function model gives many options for allocating limited water resources under drip irrigation for a desirable yield. The crop yield response factor confirmed that moderate deficit irrigation management with a drip system across the growing period can be a feasible option for okra cultivators in the water-scarce regions of Indo-Gangetic plains or similar agro-climatic conditions.