Abstract:

The study aims to verify major meteorological factors which affect the growth and development process of flue-cured tobacco in mountainous region, properly arrange field growth period, and better forecast and prevent tobacco bacterial wilt. We conducted field experiments for two consecutive years by using three main tobacco varieties of ‘Yunyan87’, ‘K326’ and ‘HN2146’ with different transplanting dates, to analyze the change rule of tobacco growth period, and define the relationship between the temperature and sunshine and the bacterial wilt and growth period of flue-cured tobacco. The results are as follows. (1) The growth period of tobacco was significantly shortened with the delay of transplanting date, mainly in the vegetative growth stage (root extension period) and reproductive growth stage (exuberant growth period) before budding. The temperature of early growth stage increased significantly with the delay of transplanting date, speeding up the development process. The accumulated sunshine hours decreased due to the shortened growth period. (2) The effect of temperature and sunshine on the growth period of flue-cured tobacco was mainly found before budding, and their primary function mainly took place during the vegetative growth stage and reproductive growth stage. Temperature was the key meteorological factor affecting the growth period of tobacco in Xiangxi. (3) The average temperature and average sunshine hours were the main meteorological factors during tobacco growth period, and the average temperature was the key meteorological factor. (4) The key control period of bacterial wilt was 63 days before tobacco transplanting and before the average temperature reached 21.82℃; and the key prevention period was before the average temperature reached 18.77℃ and 42 days before tobacco transplanting. Therefore, temperature was important in forecasting and prevention of tobacco bacterial wilt.

Key words: sunshine and temperature, flue-cured tobacco, varieties, transplanting time, growth period, tobacco bacterial wilt, effective accumulated temperature