氮肥用量对中烟100上部叶片组织结构及烟叶质量的影响OA

To address the issue of low usability of upper tobacco leaves and clarify the effects of nitrogen application rates on the leaf tissue structure and quality of upper leaves,as well as to determine the optimal nitrogen application rate for improving the usability of upper leaves,a field experiment was conducted in Zhucheng City,Shandong Province,using Zhongyan 100 as the test material.Five nitrogen application treatments were set up:N0(0 kg/hm2),N3(45 kg/hm2),N6(90 kg/hm2),N9(135 kg/hm2),and N12(180 kg/hm2).The leaf tissue structure of the second and fourth leaves from the top,as well as the chemical components and sensory quality of the upper leaves,were compared and analyzed under different treatments.The results showed that the leaf density of the second leaf from the top followed a linear-plus-platform equation with nitrogen application rate,while that of the fourth leaf from the top followed a quadratic equation with nitrogen application rate.Based on the fitted equations,the leaf density of the second and fourth leaves from the top was minimized at nitrogen application rates of 86 kg/hm2 and 96 kg/hm2,respectively.As nitrogen application increased,the potassium content of the upper leaves increased,while the sugar-to-nicotine ratio decreased.Aroma quality,aroma quantity,and total sensory score were significantly positively correlated with leaf thickness of the top four leaves.The sensory evaluation results of the N0 treatment(0 kg/hm2)were comparable to those of the N6 treatment(90 kg/hm2)and were significantly better than those of the other treatments.Considering the full development of upper leaves and tobacco quality,the optimal nitrogen application rate for Zhongyan 100 in Shandong flue-cured tobacco production is 90 kg/hm2.