Effects Of Plant Growth Regulators On Growth And Developmtet, Yield And Quality Of Flue-Cured Tobacco In Bijie

Field experiments was conducted in Bijie tobacco region in2010and2011,effects of Plant Growth Regulators on growth, physiological characteristics, ChemicalConstituents, sensory quality and economic characters weire studied, the results asfollows:1The effects of Plant Growth Regulators on tobacco growthIn Jinsha tobacco area, the gross leaf area and the top5leaves of T3have thelargest increase amplitude which are43.29%and25.27%.In Dafang tobacco area, the top5leaves of T3has the largest increase amplitudewhich is18.92%, T3also has the largest increase amplitude of the second leaf and thethird leaf.In Weining tobacco area, T2has the largest increase amplitude of the second leafarea and the third leaf area with61.94%and37.42%, the lumbar leaf area of T3hasthe largest increase amplitude of9.16%. T2has the largest increase amplitude of thesecond leaf width and the third leaf width with39.92%and25.97%.2Effect of plant growth regulator on physiological characteristics of flue-curedtobacco upper leaves2.1Effect of plant growth regulator on Predominant Enzymes of C and N Metabolismof flue-cured tobacco upper leavesThe plant growth regulator treatments enhanced the strength of C metabolish andthe level of N metabolish to flue-cured tobacco upper leaves in the vigorous growthperiod, and decreased the level of N metabolish, especially to T3.2.2Effect of plant growth regulator on histology and cytological characteristics offlue-cured tobacco upper leavesLeaf thickness of T2and T3obviously decreased when tobacco leaves reached tofixed length. Stockade tissue thickness/sponge tissue thickness and stockade tissuethickness/leaf thickness increased obviously. The treatments of plant growth regulatorprolonged the palisade cell division time leaf margin and leaf middle, and increasedthe cell number per unit area, the largest cell number in leaf margin were T3（126.01ind/mm）and T5（127.01ind/mm）,and the largest cell number in leaf middle were T2 （126.88ind/mm）and T5（126.25ind/mm）.Starch grain were big and the Electron Density were lower than CK; with theincrease of maturity of tobacco leaf, thylakoid lamellar structure discreted, thylakoidlamellar of CK,T1and T3were more than others.3Effect of plant growth regulator on economic characters of flue-cured tobaccoThe yield, output value, arerage price, fine tobacco ratio and fine and middletobacco ratio were higher than CK with the yield enhanced0.46%～1.53%, the finetobacco ratio enhanced3.1%～9.8%and the Output value enhanced2.12%～8.17%. T3had the largest increase amplitude of yield, average price and output.4Effect of plant growth regulator on Chemical Constituents of flue-cured tobaccoThe content of nicotine and nitrogen in upper leaves decreased, and the contentof nicotine decreased16.89%～5.07%and the nitrogen decreased18.58%～8.12%.T2had the highest content of potassium and chlorine with1.32%and0.42%, andT2had the lower content of total sugar with21.09%. Reducing Sugar and ration ofpotassium and chlorine change greatly between treatments, and the proportion ofnitrogen to nicotine had little difference.The content of potassium and chlorine in upper leaves increased obviously andtotally T2was the highest treatment with the increase amplitude of50.04%and119.70%. The content of nitrogen were lower than CK but T3. The content of totalsugar and reducing Sugar had the same regulator with T1、T4、T5were higher thanCK, and T2、T3were lower than CK.5Effect of plant growth regulator on neutral aroma of flue-cured tobaccoThe increase amplitude of total content of volatile aroma matter to T2and T4were16.31%and16.74%, and carotenoids catabolites were12.12%and1.03%, andneophytadiene were22.69%and25.10%of upper leaves, others were lower than CK.The Aromatic AA catabolites with T2was the highest(14.84μg/g). The products ofbrowning reaction took the order as follows: T1＞T2＞T4＞other treatments, Thecembratriendiol catabolites with T1was the highest(92.65μg/g), and other treatmentswere lower than CK.The total content of volatile aroma matter in middle leaves were lower than CK,and the increase amplitude was T5（9.04%）～T1（22.55%）, the content ofCarotenoid catabolites and The products of browning reaction and theNeophytadiene were decreased. The treatments of T2, T3and T5enhanced thecontent of Aromatic AA catabolites than CK, and T3had the highest value. The content of cembratriendiol catabolites to the treatments of plant growth regulator werehigher than CK, and T2was the highest(59.14μg/g).6Effect of plant growth regulator on sensory quality of flue-cured tobaccoThe total score of sensory quality to upper leaves increased, the decreasemainly because the decrease of the amount of aroma, Concentration, Combustion andash.Middle leaves increased the total score of sensory quality except T3with theorder T2（73.4）＞T1（72.7）＞T4（72.5）＞T5（70.8）＞CK（70.5）＞T3（70.4）,and the increase mainly because the enhance of the quality of aroma, the amount ofaroma, concentration and the aftertaste, and the combustion and ash had nodifferences.