Regulation Of Mixed Plant Growth Regulators On Potassium Nutrition And Main Quality Indices Of Tobacco Leaf

Leaf-k content is one of the important quality indices for flue-cared tobacco. Increasing the potassium contents of tobacco Leaf is still the hot point in the field of tobacco. There have some reports about plant growth regulator A increasing the potassium contents of tobacco leaf, but there have still some deficiencies for this technology measure in practical production. On the base of Liu Juanxu's study (2002), three mixed plant growth regulators were applied on top of tobacco shoot after topping by micro-field, pot culture and field experiment in this paper. At the same time, the effect of three mixed plant growth regulators under different climate was studied in Changsha Hunan and Xundian Yunnan. Potassium contents, N-compound contents, total sugar contents and reducing sugar contents of tobacco leaf were tested. Main results were as follows:1.Mixed plant growth regulators increased the potassium contents of tobacco leaf significantly. Under the four designed mixed A, B, C levels, the effect of 03(30:0.15:5) was more outstanding, and B, C didn't influence the dominant function of A when they worked some physiological function.2.Mixed plant growth regulators had different response to different flue-cured tobacco varieties, and C-3 was more outstanding. The increased potassium extent of G80, cloud and mist87and K326 was higher than that of cloud and mist85, but there wasn't different among G80, cloud and mist87 and K326.3.Mixed plant growth regulators influenced other quality indices differently. They decreased the nicotine contents of tobacco leaf significantly, and there had obvious minus relativity between potassium and nicotine contents of tobacco leaf. They decreased or increased amino acid contents of tobacco leaf, but the relativity between potassium and amino acid contents of tobacco leaf was obverse. They didn't influence the total-N, reducing sugar, ratio of total sugar and nicotine and difference between total sugar and reducing sugar of tobacco leaf.4.Under 30:0.15:5 of A, B, C levels, the potassium contents of tobacco leaf were increased significantly by using 0.8g lanolin.5. Mixed plant growth regulators all increased potassium contents of tobacco leaf in two different climate tobacco region, and handling 3 was outstanding. But in Xundian single A(30mg.kg-1) was better.6.Mixed plant growth regulators influenced other quality indices differently in two different climate tobacco spot. Same handling(t-3 and C-3) decreased the nicotine contents of tobacco leaf in Crop Place and increased the amino acid contents of tobacco leaf in Xundian significantly. They influenced the amino acid contents of tobacco leaf and achieved two contrary obvious levels in different tobacco region. They didn't influence the total-N, reducing sugar, ratio of total sugar and nicotine and difference between total sugar and reducing sugar of tobacco leaf. The ratio of total sugar and nicotine contents of tobacco leaf was different in two tobacco spot, in Xundian the ratio of total sugar and nicotine contents of tobacco leaf was most in the range of 6-10:1, and it was very harmonious, but in Crop Place it exceeded 10:1 mostly, and it wasn't very harmonious.