INFLUENCE OF IRRIGATION AND CROP RESIDUE MULCHING ON YIELD AND WATER PRODUCTIVITY OF TABLE PURPOSE GROUNDNUT (ARACHIS HYPOGAEA) IN HUMID TROPICAL ISLAND

Abstract

Field experiment was conducted during dry season of 2008-10 at Andaman and Nicobar Islands to study the influence of irrigation at critical stages and mulching on yield and water productivity of table purpose groundnut under humid tropical conditions. Experiment was laid out in split plot design with three replications by assigning irrigation at critical stages (‘No irrigation’, ‘one irrigation at pegging’, ‘two irrigation at life and pegging’, ‘three irrigation at life, flowering and pegging’ and ‘four irrigation at life, flowering, pegging and pod development’) to main plot and crop residue mulching (‘Paddy straw’, ‘banana leaf’, and ‘Gliricidia leaf’ and ‘No mulch’) to subplots. Growth and yield attributes were significantly influenced by irrigation and mulching. Application of two irrigations at life (3 DAS) and pegging (55-60 DAS) resulted in higher pod yield (3 549 kg/ha) compared to three and four irrigations which registered 2.6 and 7.7% yield reduction. Higher net returns (Rs. 41 599/ha), B:C ratio (1:8), energy ratio (15.3) and lower specific energy (4.0 MJ/kg) was recorded with two irrigations . However, one irrigation at pegging registered higher water productivity of Rs. 66/ m3. Among the crop residue mulches, paddy straw mulch registered higher pod yield (3 425 kg/ha), water productivity (Rs. 33/m3), net returns (Rs. 39 280/ha), B:C ratio (1:6) and energy ratio (15.0).