Studies on chilling requirements and chilling requirement of peach in Chengdu

The chilling requirements of peach by hydroponic method in chengdu have been investigated during 2008 to 2010.The trends of accumulation changes of chilling requirement in autumn and winter season were recorded by 7.2℃ model,0~7.2℃ model,Utah models.The ending of natural dormant in chengdu areas were significantly different for distinct cultivars.Besides,the earliest ending of natural dormancy was occurred at the beginning of Novenber.The latest ending of natural dormancy were found at the end of Feb.In addition,the ending of natural dormancy happened during the middle of Jan to middle of Feb for almost of cultivars.Comparison studies on the three models,comparison researches on beginning timing using 7.2℃ model and 0~7.2℃ model,comparison studies on previous known results indicated that 0~7.2℃ model was more suitable for chilling requirements of peach than other models if the temperature was lower than 7.2℃ to start timing.The chilling requirements for a number of cultivars have been recorded and analysis using the 0~7.2℃ model.In this model,introduction of statistics and analysis of the sources of resources to peach chilling requirement range.