Abstract: To quantify the climatic impacts on the quality of kiwifruit, we used correlation analysis, path analysis, and regression analysis to select the key climatic factors and establish the climatic quality evaluation models of Actinidia chinensis and Actinidia deliciosa, based on the quality data (total soluble solid and total acid) of kiwifruit in different areas including Guizhou, Shaanxi, Zhejiang, Hunan, and Anhui, as well as the corresponding daily meteorological observational data including sunshine, temperature and precipitation. The results showed that the key period for quality formulation of kiwifruit was sugar-transformation stage and rapid swelling stage of fruit, with temperature and sunlight as the main factors affecting the quality of kiwifruit. The climatic indicators affecting the quality of Actinidia chinensis were diurnal range of temperature during the 13th to 15th ten days before maturity (TD_13-15), sunshine hours during the 1st to 6th ten days before maturity (SSH_1-6), daily range of annual temperature (TD_y), as well as the diurnal range of temperature in fruit growth period (TD_p). For Actinidia deliciosa, the climaticindicators were the maximum temperature during the 13th to 18th ten days before maturity (T_max13-18), maximum temperature during the 1st to 3rd ten days before maturity (T_max1-3), daily range of temperature during 7th to the 9th ten days before maturity (TD_7-9), the minimum temperature during 16th to the 18th ten days before maturity (T_min16-18), average temperature during 1st to 6th ten days before maturity (T_1-6), precipitation during fruit growth period (P_p) and sunshine hours during 1st to 3rd ten days before maturity (SSH_1-3). The back substitution test and prediction test were carried out on the established climatic quality evaluation models of Actinidia deliciosaandActinidia chinensis. The proportions of the deviation between the simulated test grade and actual grade with no more than one grade were more than 90%. Thus, the models can objectively reflect the impacts of climate on kiwifruit quality.

Key words: kiwifruit, climatic quality, path analysis, TSS/TA ratio.