University College of Agriculture, 35, Ballygange Circular Road, Calcutta-100 019.
*Present address: Senior Research Officer, Tribal Area Research, College Road Phulbani-762 001 (Orissa).
There is considerable variation in the average annual yield of individual plants in an orchard and between orchards of litchi cv. Bombai. The orchard efficiency indicating yield potential varies from 33 to 54 per cent. The mean annual yield per plant for four years varies from 718 to 4458 fruits. The variation in yield has significant correlations with leaf nitrogen content, infection of leaf spot, red rust and mite and feeder root density. The yield is positively correlated at 5 per cent significance with the leaf nitrogen before flowering (0.428), and negatively correlated at 1 per cent significance with leaf spot, red rust, mite and fruit rot. The yield has also significant positive correlations at 1 per cent level with the feeder root densities, both in April and October, at the depths of 0–30 cm, 30–60 cm, 60–90 cm. Hence the variation in yield is associated with the leaf nitrogen content, and pest and disease infection. It is suggested that the actual guidelines for better management of orchards to attain higher yield should be determined after detailed experimentation using fertilizers, fungicides and pesticides.
