The Study On The Relationship Of Nitrogen Nutrition To Yield And Quality Of Burley Tobacco

The study on different nitrogen nutrition situations on the dry matter accumulation,nicotine, total nitrogen in burley tobacco were studied in Fengjie, Chongqing,the relationship of yield and quality were investaged after tobacco curing, The main conclusions were as follows:1.The amount and rate of dry matter accumulation increased with the increment of nitrogen fertilizer application. The accumulation of dry matter for tobacco in early stage were inhibited when the amount of nitrogen fertilizer exceeded 210 kg/hm2. However, when the amount of nitrogen was lower than 150kg/hm2, Postponing top-dressing time was benefit to the accumulation of dry matter. The accumulation trend for dry matter presented the rule of "slow-fast-slow" duing the process of growth and developmentThe rate of accumulation of dry matter was different with the change of burley tobacco varieties. The dry matter accumulation rate of E tobacco 4 had a high accumulation rate, KY8959 decreased after transplanting 60d.2.Plant height, stem girth, leaf area and effective leaves increased with the increment of nitrogen rates and the delay of top-dressing time. However, top-dressing had adverse effect on timely harvesting when the amount of nitrogen fertilizer was over 210 kg/hm2.3.It effected heavily to the chemical constituents in the cured tobacco leaves.The content of nicotine increased with the advancing of growth process, presenting a maximum value at the 75th day after transplanting. The speed of nicotine accumulation in treatment with top-dressing was slower in early stage, and then speeded up with the advancing of growth process. The treatments with later top-dressing time had high content of nicotine at harvesting time.The content of total nitrogen in tobacco leaves decreased with the advancing of growth process, but the extent of decrement slowed down with the increment of nitrogen application rate and the postponing of top-dressing time.The change patter on the content of total sugar and reducing sugar were followed:it first decreased and then increased, the content of total sugar and reducing suger decreased by postponing top-dressing time Under the same nitrogen level treat.4.1t effected heavily to the yield and quality of burley tobacco.The yield and output value could be increased by postponing top-dressing time with same nitrogen level. The yield and output value of burly tobacco increased with the increment of nitrogen application rate, but the output value decreased when the amount of nitrogen application exceeded 180kg/hm2 for KY8959 and 210kg/hm2 for E tobacco 4.