Effects Of Top And Nitrogen Nutrition Regulations In Rizosphere To Flue-cured Tobacco Yield And Main Chemical Qualities

In order to resolve the problem of not high quality of flue-cured tobacco caused by fertilizer unreasonable in Zhengning county, Qingyang City, Gansu Province. Field experiments were arranged in 2008-2009, to research the effects of top and nitrogen nutrition regulations in rizosphere to growth and metabolism, yield and main chemical qualities of flue-cured tobacco for appropriately increase yield and full improvement of quality.Top regulation experiment was conducted in 2008, total of 9 treatments, T1: no topping,T2: topping,T3: smearing indole butyric acid (IBA),T4: smearing ethephon (CEPA), T5:smearing gibberellin (GA),T6:smearing2,4-D,T7:smearing a-naphthy- lamine(NAA), T8: smearing cytokinin ( CTK), T9: smearing indole acetic acid (IAA).Rhizosphere nitrogen regulation experiment conducted in 2009, set up 2 treatments, T1: CK (local practices, urea UA), T2: treatment (ammonium phosphate ANP), the main results are as follows:1. The effect of top regulation on flue-cured tobacco yield, value and quality Top regulation measures significantly improved the yield, value, average price and ratio of mid-high grade leaves and significantly improved the chemical quality indicators of flue-cured tobacco leaves.(1) Topping increased flue-cured tobacco yield, value, average price and the ratio of mid-high grade leaves, but significantly decreased the potassium content of tobacco leaves, improve the nicotine content of tobacco leaves.(2) The effects of smearing exogenous hormones on flue-cured tobacco yield and value were different due to hormonal differences, but significantly increased leaf K content, and to rationalize the nicotine content of tobacco leaves.Compared with the topping treatment, smearing GA and CTK the yield, value, average price and the ratio of mid-high grade leaves of flue-cured tobacco increased by 6.0%, 2340yuan/hm2, 0.48å…ƒ/kg, 30% and 4.2% 1,365 yuan/hm2, 0.52å…ƒ/kg, 26.2%.The effects of smearing exogenous hormones to leaf potassium content and nicotine content were different by hormones varies, GA, CEPA and NAA treatments on leaf potassium content were the most effective, upper leaves were increased the concentration of potassium by 38.2%, 39.0%, 35.3%, middle leaves were increased by 33.5%, 26.9%, 32.2%, lower leaves were increased by 29.3%, 25.8%, 27.6%. The effects of GA and CTK treatments on nicotine content were most significant difference in different leaves , in the upper part of the larger increase, and the more reasonable value.(3) Smearing exogenous hormone also significantly improved other chemical quality indicatorsSmearing exogenous hormones significantly increased the leaf content of total sugar and reducing sugar, reducing tobacco chloro-ion content, 7 kinds of exogenous hormones to deal with the effects of GA and CTK most significant. Smearing exogenous hormones significantly decreased the nitrogen content in the upper leaves, so that the protein content of tobacco leaf tends to appropriate range.2. The effect of rhizosphere nitrogen regulation on flue-cured tobacco growth and metabolism, yeild output and quality(1) Compared with the UA treatment, ANP treatment significantly promoted the growth of flue-cured tobacco, ANP treatment in squaring stage the maximum leaf area, maximum leaf fresh weight and total fresh leaf mass to increased respectively by 12.3% , 13.9% and 10.7%, compared with UA in dome respectively increased by 15.4%, 11.2% and 10.0%, leaf area and leaf fresh weight increased significantly increase tobacco yield basis.(2) ANP treatment increased nitrate reductase, amylase and invertase activity in squaring and dome, not only for the nitrogen metabolism of tobacco, sugar and other organic compounds at the same time as the formation of a more carbon frame . (3) ANP treatment improved root growth, increased root activity, compared with UA treatment, ANP treatment fresh weitht respectively increased by 16.4%, 23.0% in squaring and dome, root oxidation and increased root activity 18.8%, 12.0% and 10.1%, 6.6%.(4) The rhizosphere nitrogen measures improved the effectiveness of soil phosphorus, compared with the UA treatment, ANP treatment significantly reduced the rhizosphere pH, and thus improve the effectiveness of phosphorus in rhizosphere.(5) ANP treatment the yield, value, average price and ratio of mid-high grade leaves were higher than UA treatment, compared with UA, ANP treatment the yield, value and average price increased by 11.57%, 4095 yuan/hm2, 0.18 yuan/kg, ratio of mid-high grade leaves increased of 10 percentage points.(6) ANP treatment significantly increased the potassium content in the lower leaves significantly increased the upper leaf in total sugar, reducing sugar content, and to rationalize the nicotine content in tobacco leaves.