Chilling damage comprehensive assessment methods for rice.

Abstract

Based on the grey correlation analysis method, the chilling damage inducing factors and yield structure traits of rice in different growth stages, and the yield structure traits and final yield of rice were regarded as two grey systems. By seeking the grey relations of the grey systems and using the multi level grey correlation analysis method, the comprehensive assessment model of rice chil-ling damage was constructed, and the comprehensive assessment indices of chilling damages in sepa rate stages were established. The rice chilling damages at 27 stations in Northeast China from 1961 to 2015 were assessed separately. The results showed that there was a good corresponding relationship between the chilling damage and the rice yield. The low temperature during the vegetative growth stage, the vegetative growth and reproductive stage, the pollination stage or the grain filling stage significantly decreased the panicle number per plant, the average panicle grain number or the thousand kernel mass, and increased the empty grain rate. A good correspondence existed between temperature and rice yield in the typical chilling damage years.