Abstract:

Based on the mean air temperature data at 62 weather station of Heilongjiang province from May to September during 1961-2010 and a standard on cool injury of rice (CIR), spatial and temporal distribution of delayed CIR in mild, moderate and serious grades was analyzed using methods of an accumulated anomaly and a wavelet analysis in order to provide references for prevention of CIR. The results indicate that delayed cool injury of rice occurs mainly in Heihe, Qiqihaer, eastern Harbin, western Mudanjiang and eastern Sanjiang plain. There is a significantly variation for delayed CIR during 1961-2010 in Heilongjiang province. The CIR has a turning point in 1994 and seldom appears after 1994. The CIR decreases significantly after 2000. The cycles of delayed CIR are 21 years and 9 years for mild and middle grades respectively, while it is 21 years for serious grade.

Key words: Rice, Delayed cool injury, Cycle