Abstract:
In order to clarify the main meteorological risk factors and their spatial and temporal distributions for flue-cured tobacco growing in Guizhou Province, daily average temperature, maximum temperature and rainfall data of 64 counties (districts or cities) in Guizhou Province from 2008 to 2017 were gathered. The main meteorological risk factors of flue-cured tobacco at different growth stages in different counties and districts were evaluated using cluster analysis method to classify the meteorological risk factors. The results showed that the main meteorological risks were low temperature from the shoot restoring stage to the root extending stage (average daily temperature ≤13 ℃ from late-April to mid-May), high temperature at the mature stage (the highest daily temperature ≥35 ℃from mid-July to late-August), low temperature at the late mature stage (average daily temperature ≤20 ℃ from early-August to early-September) and heavy rain (daily rainfall ≥50 mm). The risk of low temperature from the shoot restoring to the root extending stage as well as the late mature stage mainly occurred in western Guizhou, including Weining and Dafang in Bijie, Shuicheng in Liupanshui, and Pu'an in Qianxinan. Among them, Weining in Bijie had the highest risk of low temperature whose average number of low temperature days in the early period (from late April to mid-May) was 12 days and was as high as 40 days in the latter period (from early August to early September). The risk of high temperature at the mature stage mainly occurred in Tongren and Qiandongnan. Among them, the risk of high temperature for Yanhe in Tongren was the highest. Within the growth stages of flue-cured tobacco, the rainfall was abundant, but the inter-annual differences were large. The rainfall in the southwest and the eastern regions was significantly higher than that in the central region. The central region only experienced drought in a few years with the longest consecutive rain-free period of 10-15 days. Heavy rains occurred in Anshun and its surrounding counties. The annual average number of rainstorm days was about 4 days, and the average annual rainstorm rainfall was greater than 300 mm. Songtao in Tongren faced dual risks of heavy rain and high temperature at the mature stage.