Abstract: Based on the daily meteorological data (1958−2019), the statistical production data (1978−2018) and the observed planting data of apple (2010−2018) at Zhaotong in Yunnan, the change of agricultural climatic resources and meteorological disaster were analyzed, while the local climatic potential production on apple was estimated using linear trend analysis and step by step correction. The aim of this paper can make more efficient and rational use of agricultural climate resources and scientifically guide to the apple industry layout. The results showed that: (1) during 1958−2019, the duration days of frost-free period and stable passing through 10℃ significantly increased by 3.5 and 4.5 days, respectively. Theoretically, the duration can match the apple needs. However, the starting date of flower bud expansion and mature were more advanced than the last frost date and the ending date of stable passing through 10℃; (2) According to the actual phenology of apple at Zhaotong from 2010 to 2018, we calculated the most possibility phenological from the starting date of stable passing through 3℃ and the ending date of stable passing 13℃.So in this period of 1958−2019, average minimum temperature, average temperature and maximum temperature were 11.8, 16.1 and 22.6℃ respectively, with different increase rate of 0.1, 0.04 and 0.05℃·10y−1. The average daily temperature range was 10.89℃ with decreased rate of 0.2℃·10y−1. The precipitation and sunshine hours decreased with 1.0mm·10y−1 and 6.7h·10y−1, respectively; (3) In the past 62 years, the risk of low temperature during flowering period was less, which was not the main agricultural meteorological disaster at Zhaotong. The risk of continuous rain was higher from June to September, which occur in the key growth period of apple; (4) The maximum theoretical yield of apple was about 100t·ha−1. With the restrictions of temperature and water, the production potential of light temperature and climate accounted for 83.0% and 76.0% of the photosynthetic production potential, respectively. However, the actual apple yield and the statistical yield across the whole county were only 35% and 10% of the photosynthetic production potential. With the development of technology and breeding of varieties, the gap is gradually narrowed. Generally, the meteorological conditions at Zhaotong can fully meet the needs of apple growth and development. Through the application of reasonable and efficient planting techniques and the full excavation of agricultural climate resources, the difference in apple yield can be further reduced and the quality of apple can be improved.

Key words: Apple, Agro-climatic resources, Potential production, Meteological risk, Southwest cool highland, Agricultural threshold temperature