Effect Of Topping Stages On Flue-Cured Tobacco Reproductive Characteristics, Yield And Quality In Different Ecological Regions

Through field experiment in Henan Xuchang, Hunan Liuyang and Sichuan Liangshan, the paper studied effect of topping stages on flue-cured tobacco growth, yield and quality in different ecological conditions to find tobacco production problems in different ecological regions and chance the most appropriate topping stage. The results of the test are as following:1 Effect of topping stages on flue-cured tobacco growth in different ecological regions: flue-cured tobacco overall growth trend in Henan Xuchang is stronger than in Hunan Liuyang and in Sichuan Liangshan. Topping stages are positively related to stems height, nodes length and the number of effective leaves, aren't related to stem circumstance. Length of flue-cured tobacco upper five leaves is larger in Hunan Liuyang than in Henan Xuchang, width is larger in Henan Xuchang than in Hunan Liuyang; they decline gradually with topping stages delaying. Total sugar on upper leaf increase then decline, total nitrogen and nicotine decline, starch content changes irregularly with topping stage delaying.2 Effect on flue-cured tobacco economic properties: the yield and output value in Hunan Liuyang are higher than in Henan Xuchang, and they are higher than in Sichuan Liangshan, the proportion of high and medium tobacco in Hunan Liuyang is the highest, Henan Xuchang and Sichuan Liangshan are almost .All yield, the output value and the proportion of high and medium tobacco increase with topping stage delaying, they are the highest in early flower, then declined.3 Effect on flue-cured tobacco physical characteristics: flue-cured tobacco overall leaf length and width in Hunan Liuyang are larger, Henan Xuchang Secondly, Sichuan Liangshan are smaller and the leaves are narrow. Leaf quality weight and thickness of Sichuan Liangshan are larger, Hunan Liuyang Secondly, Henan Xuchang are smaller. Single-leaf weight of different parts is inconsistent in different regions. Effect of topping on upper leaves are greatest, central leaves secondly, low leaves are smallest. With topping stages delaying, leaves length, width, single-leaf weight, leaf quality weight and thickness show a declining trend.4 Effect on flue-cured tobacco chemical composition: tobacco chemical composition of Hunan Liuyang is most coordinate, starch content of Sichuan Liangshan is too high, reducing...