| Topping in the tobacco agricultural production is an importantcultural practices, which aims to eliminate the top growth advantage, promote thegrowth of leaves, leaf inclusions is improved and ensure the formation of the qualityof tobacco. However, the relationship between changes in the source database toppinglead and promote the development of secondary roots, so root absorption of nutrients,especially nitrogen large supply of upper leaves, making the upper leaves maturedchemical components disorders, leaf tissue stiffness, and because increase in lateralroots, the site of more synthetic nicotine, together made up his cause mechanicaldamage, resulting in the ability of nicotine biosynthesis strengthened, resulting in theaccumulation of nicotine content in upper leaves, reducing the upper leaves ofindustrial availability. To solve this practical problem of production, we set up thetreatments of root pruning after topping at different times, and the treatments of rootpruning after the recovery of different parts of tobacco leaves; next, we examined thedistribution of nitrogen in different organs of tobacco and the quality formation indexof the upper leaves; at last, according to the effect of different treatments on therelationship of source and sink of tobacco plant, the best root pruning period oftobacco after topping was screened. The results are as follows:1without harvest tobacco processing in different cutting timeAfter topping without harvest tobacco root pruning processing, tobacco rootpruning after topping15d the accumulation of dry matter and nitrogen significantlyincreased; the nicotine and crude protein content of upper leaf decreased significantly;potassium content was significantly increased.10d and25d after topping, Root pruning was employed, and we found the sugar of upper leaf content decreased, andthe total amount of neutral aroma and carotenoids also reduce; By contrast, the rootpruning treatment after topping15d and20d neophytadiene content is dramaticallyincreased. In summary, without harvest lower leaves after topping15d root pruningupper leaves accumulate more dry matter process, coordinating the chemicalcomposition, increasing level of aroma, which is benefit for improving the quality oftobacco.2Remove the lower leaves processing in different cutting timeThe root pruning treatment after topping the lower harvest, the earlier the timeof root pruning the greater on dry matter and nitrogen accumulation in promoting. Thenicotine content and crude protein content of upper leaves was significantly reducedunder the root pruning after topping15d. The root pruning treatment after topping10d and25d, the upper leaves of reducing sugar content was significantly reduced. Theroot pruning treatment after topping15d, the potassium content of upper leafincreased significantly. Root pruning deal weakened the synthesis of neutral aromacomponents, the synthetic of cembrane aroma substances are significantly weakened;but the synthesis of neophytadiene is significantly promoted, the most significant ofroot pruning treatment after topping in the20d. The root pruning treatment aftertopping10d and15d, the carotenoids and brown aroma of product synthesis has a rolein promoting. By contrast, The root pruning treatment after topping20d with harvestlower leaf, coordinating the chemical composition, increasing level of aroma, whichis benefit for improving the quality of tobacco.3Remove the middle leaf and the lower leaves processing in different cuttingtimeRemove the lower leaves of tobacco root pruning on dry matter accumulationhas some subduction, but it promotes the dry matter accumulation of the upper leaves,the later the time of root pruning the more of obviously the dry matter accumulate.The root pruning treatment reduced the accumulation of nitrogen in tobacco plants, but the nitrogen accumulation of upper leaves was significantly promoted, the laterthe time of root pruning the more of obviously the nitrogen accumulation.Comprehensive analysis, the deal of root pruning promoted tobacco drymatter and nitrogen accumulation, the sooner the time of root pruning the moreobvious. Remove the lower leaves> without harvest leaves> remove the lower leavesand middle leaves. Different parts of the tobacco harvest, time to deal with all thedifferent root pruning promotes the upper leaves of dry matter and nitrogenaccumulation. The deal of removing the lower leaves with the most obvious, it waslittle difference between the treatments without harvested and the treatment ofremoving lower leaves. The root pruning treatment after topping15d in favor of thecontent of the specific aroma into the upper leaf to improved and chemicalscoordination, and remove lower leaves> without harvest leaves. Removing the lowerleaves of tobacco plants which after topping20d root pruning treatment, the nicotineand crude protein content of upper leaves were lower than the other treatments, thepotassium and reducing sugar content increasing, increasing level of aroma, especiallythe neophytadiene content has been greatly improved, which is benefit for improvingthe quality of tobacco. After topping20d was the best root pruning period... |
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