Effects Of The Nitrogen Management And Interactions With Leaf Number On Growth Yield And Quality Of Burley Tobacco

Based on field experiments, the studies were carried out to investigate the effects of nitrogen rate and basal-dressing proportion on dynamic changes in dry matter accumulation during the growth period of burley tobacco, and on growth and development and yield and quality of tobacco leaves after air-curing in Dazhou county of Sichuan and Xuanhan of Dazhou from 2009 to 2010. The effect of difference nitrogen rate and the ratio of left on yield and quality for main burley varieties was also investigated in Dazhou, Sichuan.. The results were as follows:1. Different nitrogen and basal-dressing proportion of burley tobacco had a significant effect on the agronomic traits and economic characters. The plant height, stem girth, area of largest leaf was much greater than the control after treated with nitrogen treatments. In the scope of 0 ~ 300 kg/hm~2, the agronomic traits of various processing tobacco production, production, growth later plant height, stem girth, area of largest leaf showed the increasing trend with the increase of nitrogen. In the scope of 0 ~ 255 kg/hm~2, the increasing of nitrogen could improve the average and the proportion of secondary smoke. In the scope of 0 ~ 210 kg/hm~2, the increasing the basal-dressing proportion could increase yield, value, average, improve the proportion of superior tobacco, and that the lower nitrogen, the more obvious. Only from the economic characters perspective, with nitrogen 210 kg/hm~2, the ratio of 40% furrow best treatment combinations.2. Different nitrogen and basal-dressing proportion of burley tobacco have a significant effect on the dry matter accumulation dynamics and nitrogen utilization efficiency. At the different growing stages, the effect of the proportion of nitrogen rate and basal rate to dry matter accumulation showed different. Period of maximum growth rate related to the nitrogen rate, and the period backward delay with the growth of the nitrogen rate, increasing the proportion of fertilizer could increase per dry matter accumulation, and the smaller N Supplemental proportion ,the greater the impact on dry matter accumulation. Nitrogen and basal-dressing proportion had significant effects on nitrogen utilization efficiency. Under the same nitrogen rate, the greater the proportion of basal fertilizer nitrogen, the lower nitrogen utilization efficiency; and the greater basal-dressing proportion, the smaller effect on nitrogen utilization efficiency.3. Nitrogen and basal-dressing proportion had different effect on conventional chemical composition. In the scope of 0 ~ 300 kg/hm~2, the contents of burley tobacco of total nitrogen, nicotine, k+ and k+ to Cl - ratio in burley tobacco were increased, while the total sugar content, reducing sugar, Cl - and total nitrogen to nicotine ratio were decreased along with the increase of nitrogen application amount. When nitrogen rate was more than 255kg/hm~2, the total nitrogen content of tobacco was exorbitant as well as the nicotine, resulting the chemical composition inharmonious, tobacco quality lower. With low application rate of N fertilizer, the lower basal-dressing proportion of internal quality in favor of the formation of tobacco, more than N 255 kg/hm~2, the lower basal-dressing proportion was not conducive to the formation of good quality.4. The contents of the total neutral aroma components, middle leaves of every treatment, increased first and then decreased with the increase of nitrogen fertilizer rate, indicating that too much nitrogen fertilizer was not conducive to the formation of burley aroma. With low application rate of N fertilizer, increasing the basal-dressing proportion could add to the total amount of the neutral aroma components, with high application rate of N fertilizer, the basal-dressing proportion influenced little to the total amount of the neutral aroma components, neophytadiene content with the increase of nitrogen application rate first increased and then decreased again to increase, solanone with the amount of nitrogen content increase had decreased, Megastigmatrienone nitrogen content increased with the addition, the greater the proportion of top dressing, the higher its content.5. Different nitrogen and leaves had a great impact on agronomic traits, conomic traits and botanical characters of burley tobacco. Amount of nitrogen fertilization could improve the early growing tobacco, which was conducive to growth and development of early tobacco, but the nitrogen was more than 195 kg/hm~2 (N2), the excess nitrogen will inhibit the development of the rosette stage tobacco. The nitrogen level, plant height, stem thickness, pitch, maximum leaf length leaf width has decreased with the increase in remaining leaf number, and more leaves had "dilution" effect on the fertilizer with. There was an increasing trend in leaf yield, production value with the increase of nitrogen, the average and the proportion of secondary smoke increase first and then decrease. Single look from economic characters, When nitrogen rate was 120 kg/hm~2 and 195 kg/hm~2 ,desirable to leaf 22, When nitrogen rate was 270 kg/hm~2 desirable to leaf 24. Leave area after air-curing, leaf thickness and leaf weight were shown the increasing trend with the increasing nitrogen rate, with the increase in the number of remaining leaves decreased. That suitable nitrogen, suitable nitrogen, leaving less leaves could improve the leaf area, per leaf weight, and help improve the quality of tobacco.