Abstract:
In order to study the effects of different transplanting and harvesting time on the temperature factors for the development of the upper six leaves in the central tobacco-growing area of Yuzhong, a field experiment with different transplanting and harvesting dates was designed using the tobacco variety Zhongyan100. The aim of this study is to make the climatic factors such as light, temperature and water reconfigured during the growth period of upper six flue-cured tobacco leaves and to provide a theoretical basis for analyzing the temperature index of the upper six slices formed in Yuzhong and determine the appropriate transplanting and harvesting time. The results showed that: with the shift of transplanting time, during the upper six leaf growth period, the last six leaf mature period, and the whole growth period,>0 ℃ accumulated temperature,>10 ℃ accumulated temperature, daily temperature range,>20 ℃ days, the highest temperature>30 ℃ days showed a gradual decrease trend. The average temperature of the upper six leaf growing season and the accumulated temperature of >20 ℃ were all relatively higher with the April 25 transplanting treatment. The daily temperature range gradually increased during the last six leaf mature period and the harvest time was postponed. The average temperature gradually decreased. Diurnal temperature difference, the maximum temperature> 30 ℃ days did not change significantly. The other meteorological factors as a whole showed an increasing trend. In the process of the growth of the top six leaves, the average temperature, daily temperature range, and the maximum temperature were effected by the transplanting time greater than the harvesting time, and the accumulated temperature,>20 ℃ days was closely related to the harvesting time.