EFFECT OF DROUGHT CONDITION ON GROWTH, YIELD AND GRAIN QUALITY OF UPLAND RICE

Thus, the objective of this study was to investigate the effect of drought condition on growth, yield and grain quality of two varieties in upland rice: Nangdam and Lebnok. The experiment was performed at the King Mongkut’s Institute of Technology Ladkrabang, Chumphon Campus, Thailand during July to November, 2010. The study was conducted in randomized complete block design with four replications. This results showed that Nangdam and Labnok varieties were got 12.40-97.10 mm of average monthly rainfall in the vegetative, reproductive and grain formation to ripening stages. Nangdam and Lebnok had days to booting of 72 and 68 Days After Germination (DAG), respectively, days to 50% flowering of 93 and 90 DAG, respectively, which were higher than the normal average of 2 to 6 days. The two tested varieties had low grain yields of 29.12 and 26.20 kg/ha, respectively, when they were grown at the low level rainfall. All varieties had higher number of empty grain of 48 and 33 grain per panicle, respectively, number of low perfect grains of 53 and 57 grain per panicle, respectively, number of imperfect grains of 35 and 30 grain per panicle, respectively, chalky grains of 17.50 and 15.20%, respectively and breaking grains of 0.75 and 2.50%, respectively. However, there were no significant different among those traits between the two varieties. The two varieties of upland rice had smaller grain which was lower than the standard.