Effects Of Growth Periods To The Characteristics Of Agronomy And Quality Of Flue-Cured Leaf Tobacco In Tree Mild-Aroma Type Regions

In this experiment,we explored the impact of climate on tobacco characteristics of agronomy and internal quality by regulating the date of transplanting and harvest of tobacco artificially,in order to investigate and clarify the relevance of basic metabolism and local climatic and ecological factors in different Mild-aroma tabacco sub-regions of Yunnan and in different time. We conducted a experiment about the relationship between the quality of Mild-aroma tabacco and the growth time in three Mild-aroma ecological zones called Huaning, Yongsheng and Ninger. The species were Yunyan87, we established two factors named transplanting period (T) and harvest periods (C) marked three levels and a total of nine combinations.More specifically,transplanting period (T) were divided into three levels of 14 days in advanced, normal time and 14 days delayed.Similarly,harvest periods (C) were divided into three levels of noral time,7 days delayed and 14 days delayed.We collected 36 kind of soil sample,216 piece of drying and green tabacco and 54 piece of flue-cured tobacco.We drew the following conclusions:(1) The change of climate mainly impact agronomic traits of early tabacco. Agronomic difference caused by transplanting period will decrease gradually during tabacco growth. The factor of climate will cause a great impact on value and yield, simultaneously, the combination of climate that can get optimal value and yield is differen in different area. Agronomic differences caused by transplanting period and differences in soil will gradually decrease during development in tobacco, and poor tabacco will be less sensitive for transplanting period, appropriate delay recovery can increase the proportion of superior tobacco.(2) As for three Mild-aroma tabacco ecological region, the variation of content of new chlorogenic acid, caffeic acid, rutin and kaempferol glycosides is similar:rising from rosette stage to harvest, showing a downward trend after harvest.Other polyphenol content has no specific trend.(3) Total sugar, reducing sugar, sugar alkali ratio is similar in each ecological zone: rising from rosette stage to the period of vigorous growth, decreasing from the period of vigorous growth to topping time, reaching the highest form topping time to harvest,decreasing again after harvest.he total nitrogen ratio is similar in each ecological zone:decreasing in the entire growth period.There is no significant difference between each ecological zone and each treatment. Nitrogen alkali ratio is similar in each ecological zone:decreasing from rosette stage to topping time, reaching the highest form topping time to harvest, decreasing again after harvest Water-solubility chloride ion ratiois similar in each ecological zone:rising from rosette stage to the period of vigorous growth, decreasing from the period of vigorous growth to harvest, almost no change after the mature period.No obvious regularity of other conventional chemical composition change.(4) The growth period and the average sunshine time and accumulated light and rainfall and accumulated temperature present a significant positive correlation (p < 0.05) in all three areas; the entire growth duration and average rainfall, average temperature present a significant negative correlation (p< 0.05) in all three areas. The main climate factor influencing tabacco growth differs from each other with different area. Rainfall is the dominant climatic factor in Huaning, temperature in Yongsheng and light in Ninger.(5) The dominant climate factor influencing tabacco chemicals, value and yield differs from each other with different area, the same as correlation. In addition, the dominant climate factor influencing chemical composition of middle and upper leaves is also different.