Growth and yield of rice as affected by saline water treatment at different growth stages

摘要

Rice cv. Janganbyeo was cultivated in Korea Republic during 1999-2000 by irrigating the saline waters of high salinity (3.0%) and medium salinity (1.5%) for 4 days, and low salinity (0.5%) for 30 days at the tillering, early meiosis and heading stages. Leaf injury due to salinity was most severe at the tillering stage in 1999, and at the heading stage in 2000. Heading date was delayed by 1-5 days by treatment of saline waters only at the tillering stage. Culm length and panicle length were most severely shortened by treatment at the early meiosis stage. Yield and yield components, except for panicle number, were decreased most by the high salinity treatment regardless of the growth stage. In particular, ripening ratio and grain weight, among the yield components, were decreased most conspicuously by the saline water treatment regardless of the salinity and growth stage. In terms of grain weight, grain-filling rate and duration, there was no remarked difference among the concentrations and treatment durations of saline water at the tillering stage. However, among the concentrations and treatment durations of saline water at the early meiosis stage, their reductions were highest when treated with high salinity for 4 days and followed by low salinity for 30 days. Their reductions were very severe only when treated with high salinity for 4 days at heading stage.