Effects Of Applying Auxin And Potassium Fertilizer On Physiological Characters After Topping And Quality Of Flue-Cured Tobacco

Field trials were carried out in Luoshan county and Zhengzhou of Henan province from 2004 to 2005. Effects of applying aution and potassium fertilizer on the root growth, stress-resistance, carbon and nitrogen metabolism, pigment content, some chemical components, volatile aroma matters and precursor aroma matters and economic characters after curing were studied. The results were summarized as follows:1. Effects of applying aution and potassium fertilizer on root characters of flue-cured tobacco: absorption ability and the second reproduction of roots were promoted by applying IAA and K₂SO₄ fertilizer which made tobacco plants have great potential of absorbing potassium, especially pasting again a week later. The root activity of treatment T3, T5 and T6 was improved obviously, and T6 had much higher ATP activity than the other treatments in this trial. Compared with T2, the order of increasing range of roots dry weight was T6 (52.76%) > T5 (22.33%) > T3 (10.11%) > T4 (8.55%).2. Effects of applying aution and potassium fertilizer on synthesizing nicotine and absorbing potassium of flue-cured tobacco root: compared with T2, nicotine synthesized in the root could be controlled when treated with applying IAA and K₂SO₄ fertilizer, and the order of decreasing range was T6 (44.94%) > T5 (38.63%) > T3 (20.25%) > T4 (8.02%). The ability of absorbing potassium weakened with the days increasing after topping, and the order of decreasing range of potassium in roots was T2 (73.28%) > T4 (70.13%) > T3 (69.22%)>T5 (63.23%) >T6 (59.72%) at 30d after topping compared with the topping day.3. Effect of applying aution and potassium fertilizer on stress-resistance enzyme of flue-cured tobacco during field stage: POD, SOD and CAT activity decreased with the days increasing after topping. The order of POD and SOD activity was T6 > T5 > T4 > T3 > T2 > T1, and showed significant difference at the 0.05 level among treatments at the 30d after topping. The CAT activity of T6 showed the superiority to the other treatments in stress-resistance due to pasting IAA 2 times and applying K₂SO₄ fertilizer from 20d to 30d after topping. PPO activity indicated the trend of increasing earlier, then decreasing with the days increasing after topping, and the order of PPO activity at the mature stage (30d) was T6 >T5>T4>T3>T2>T1.4. Effects of applying aution and potassium fertilizer on carbon metabolism of...