Abstract

Permanent plots were established and maintained in a young teak plantation at panayangode in the Nilambur Forest Division to demonstrate the impact of defoliation caused by the insect Hyblaea puera on growth of teak. Two plots, half a hectare each, were laid out in a plantation raised in 1993. One of the plots was left to natural insect defoliation and the other, protected against the teak defoliator whenever infestation occurred. Six-monthly measurements of height and GBH were taken of all trees inthe two plots. Results of the first 5 - years period showed that in the protected plot there was 45 per cent increase in mean height and 19 per cent increase in GBH over the control. The two plots are being maintained for further observation