Chitosan is a biopolymer applied to plants in order to increase the key enzymes related to the
closure of the plant’s stomata resulting in reduction of water loss. The aim of this experiment was to
determine the effect of chitosan on drought recovery and grain yield of rice under drought conditions.
The experimental design was arranged in RCBD with four replications of five treatments: sufficient
irrigation, drought without chitosan, chitosan applied before drought, chitosan applied during drought
and chitosan applied after drought. The experiment was conducted in a greenhouse at the Department of
Plant Production Technology, Rajamangala University of Technology Suvarnabhumi, during April to
August 2005.The results revealed that the treatment applied with chitosan before drought gave the
highest yield and yield components and also showed good recovery. Furthermore, the percentage of
damaged leaves was less than those of the other treatments. From this study, it is suggested that the
severity of rice plants damaged from drought was reduced by chitosan application.
Key words: drought stress, chitosan application, rice (Oryza sativa L.)