Abstract:

For the purpose to supply the quantitive index of severe cold disasters and cold resistance on cotton, the simulated experiment of low temperature, applying intelligent artificially climate box, was carried out in Wulanwusu Agro-meteorological Experiment Station in Xinjiang during 2003-2005. The responses of cotton at flowering and boll-forming stages to low temperature and duration of the low temperature were studied. The results showed that, the leaf, bud and bell of cotton broke off abnormally after supplying low temperature. The leaf began to break off on the eighth day, and the reduced rate was more than 35% in the treatment of low temperature 11.5-18.5℃ for 2-4 days, but the bud & bell was on the sixth day and 55% respectively in the same treatment. The reduced rate of leaf was less than 25%, and the leaf numbers was stable on the 18th to 23rd, and the reduced rate of bud & bell were all more than 70%, in the treatment of low temperature 11.5-22.5℃ for 2-4 days. The comprehensive analysis showed that, the response of bud and bell to suffer the same low temperature range were more sensitive than the leaf, and the reduced rate were more serious than the leaf during the flowering and boll-forming stages. The two treatments with the different minimum temperature and the same maximum temperature, the smaller diurnal temperature the higher decrease rate of leaf.