Effects of Water Stress at Different Growth Stages on Growth and Yield of Khao Dok Mali 105 Rice Variety

Abstract

The experiment was conducted in greenhouse, Departrnent of Agronomy, Faculty of Agriculture, Khon Kaen University in 1995. The objective of the research is to study the effects of water stress at different growth stage on growth and yield of Khao Dok Mali 105 rice variety. The result of the study found that Khao Dok Mali 105 subjected to water stress at vegetative stage combining at panicle initiation and flowering stages gave the lowest in grain yield, by reducing 38 percent as compared to control. This due to the lowest in panicle number per hill, spikelet number per panicle, 1000 grain weight and the highest percentage of unfilled grain. By considering of single water stress, the lowest grain yield was obtained when the rice crop subjected to water stress at flowering stage, by reducing 32 percent as compared to control. Khao Dok Mali 105 subjected to water stress at panicle initiation has little effect on grain yield as compared to the other growth stages. This due to the crop is better maintain the cell turgor when subjected to water stress and rapid recovery after removing water stress.