Effects of Climate Factors for Different Transplanting Dates on Quality and Ripe Tissue in Flue-cured Tobacco
|School||Henan Agricultural University|
|Keywords||Transplanting dates Climate factors Chemical composition Mature tobacco organizations Flue-cured tobacco|
Based on tobacco-growing areas of Lincang in Yunnan Province in this paper, climatic factors at different transplanting dates were analyzed. The climatic feasibility indexes(CFI) and chemical components usability indexes(CCUI) of flue—cured tobacco was estimated by applying membership function and estimating weight values for each index by using principal components analysis, and the climatic feasibility of tobacco was evaluated properly. Analyses were conducted on similarity between climatic conditions of tobacco at different transplanting dates in Lincang and corresponding climatic conditions in foreign high-quality tobacco-growing areas.The influences of transplanting date on the botany traits, physical traits, routine chemical components,the contents of petroleum ether extracts, flavor constituents content and tissue structure of mature tobacco leaf, and the correlations of mature tobacco leaf tissue structure at different transplanting dates and climatic factors were also studied. The main results were indicated as follows:The research on climatic factors at different transplanting dates indicated that: the rainfall, the mean temperature, the accumulated temperature of≥10℃and air humidity increased, and the hours of sunshine reduced from T1 to T6. The climatic feasibility indexes (CFI) of each treatment were all in the suitable scope. The CFI (0.873) of T1 was the largest; that of T6 was the smallest, and that of T4, T5 and T6 were lower than the mean. CFIs of diffident transplanting dates treatment showed the trend of T1>T2>T3>T4>T5>T6. The diffident transplanting time treatment had significant correlation with CFI. The comparability analysis was conducted on the climatic conditions under different transplanting dates between Lingcang and foreign high-quality tobacco-growing areas, and the similarity was high. The average Euclidean distance of climatic conditions of tobacco at different transplanting time was minimal between Lingcang and Brazil, and belonged to significant similar level. The Euclidean distance gradually increased from T1 to T6.The research on the influences of different transplanting dates on the botany traits indicated that: the period of field growth gradually reduced from T1 to T5, and reached the shortest at the transplanting date of T5, then began to increase at the transplanting date of T6. The plant height and leaves were gradually increased from T1 to T6, but the differences of internodal distance and stalk circumference among treatments were not obvious. On the economic traits, the yield of T5 was significantly higher than the other treatments; and that of T4was the lowest. The highest of output value was T2, and the lowest was T1.The effects of different transplanting dates on the physical traits in Flue-cured Tobacco leaf were relatively slight. The mean of leaf weight and that of length were close respectively, and the changes of dragging force and filling value were not obvious. But the differences of leaf thickness were obvious among different transplanting dates. The minimal of leaf thickness was T4, and the max was T5. The changes of single leaf weight were also obvious.T5 had the max single leaf weight. Leaves of T4 were thin and slight; stem ratio of it was high, and appearance quality of it was not good.The changes of routine chemical components were occurred by the differences of climatic conditions under different transplanting dates. The effects of different transplanting dates on total sugar and reducing sugar were slight, and differences among treatments did not reached significant level. The effects of different transplanting dates on content of total N only occurred on top leaf. Total N contents in upper leaf of T5, T6 were relatively low. Nicotine content of each treatment was around 12%, which is the most optimal content, but the content of nicotine in lower leaf was low in general. The coordination among chemical components of T5, T6 was good. Considering the chemical components usability indexes (CCUI) at different transplanting time, mean of which was 0.77. The CCUI of T4 was the largest, and that of T2, T3, T5 were all smaller than the mean. The CCUIs of diffident transplanting time treatment showed the trend of T4>T6>T1>T3>T5>T2.The influences of different transplanting dates on the content of petroleum ether extracts indicated that: the highest of petroleum ether extracts content was T2, and the lowest was T6. The content of petroleum ether extracts approximately showed normal distribution from T1 to T6. Petroleum ether extracts content of treatment arranged in middle was the highest, while that of treatment arranged at end was the lowest.The influences of different transplanting dates on flavor constituent amount were significant. The flavor constituents amount at diffident transplanting time treatment changed in a large range, with the trend of T6>T4>T5>T1>T3>T2. The flavor constituents amount of T5, except the content of neophytadiene, was the highest, and that of the rest treatments showed the trend of T6>T2>T1>T4>T3.The research on the influence of transplanting time on the tobacco leaf tissue structure indicated that the ratio of stockade tissue thickness/sponge tissue thickness present the trend which reduced first and turned down gently later, and the max of stockade tissue thickness and sponge tissue thickness was T1, and the lowest was T3. With the thickness of stockade tissue and sponge tissue at the average level, the total aroma constituents and chemical composition were best. Additionally, the stockade and sponge tissue thickness all had the same tendency at the different transplanting time, and the thickness of upper and lower epidermal cells did not have significant differences among different transplanting time.The research on the correlation of mature tissue in different leaf-position leaves with climatic factors at different transplanting time indicated that : Only in lower leaves, sponge tissue thickness(Y3), total tissue thickness (Y5)showed negative correlations with the mean temperature during root extending stage(X1), vigorous growing stage (X2)and mature stage(X3) , the rainfall during root extending stage(X4),vigorous growing stage(X5) and mature stage(X6),the accumulated temperature of≥10℃(X7), and the daylight hours of field period (X8) and the air humidity of field period, and the correlation with X3 reached an extremely remarkable level. While, mature tissue had not significant correlation with climatic factors in the other leaf-position leaves.