Effects of Different Nitrogen Forms and Fertilization Time on Growth and Development and Quality of Flue-cured Tobacco

[Objective] The study was to provide the theoretical and technical basis for the production and industrial needs of flue-cured tobacco.[Method] The test was carried out in Liangfeng village,Jiaoyuan Town,Xuanen County of Enshi Autonomous Prefecture in 2007 with Yunyan 87 as the test cultivars and 4 different fertilizer treatments were designed on the basis of local soil fertility condition.The agronomic characters,economic characters and normal chemical components of flue-cured tobacco with different treatments were detected,and the effects of different nitrogen forms and fertilization time on the growth and development and quality of flue-cured tobacco were explored.[Result] The number of effective leaves and leaf area per plant had no obvious differences among the 4 treatments,other indexes of L3(the treatments of base fertilizer being applied ahead of 30 d) significantly surpassed that of CK(the treatment being applied inorganic fertilizer only),the largest leaf width,dry weight of roots,yields of unit area,output value and the ratio of middle and superior tobacco of L3 was 24.87%,38.50%,28.74%,58.80% and 28.38% higher than that of CK resp.[Conclusion] The combining application of organic nitrogen and inorganic nitrogen,and the organic nitrogen being all applied ahead of about 30 d as base fertilizer could promote the growth and development of tobacco,and increase its yield and quality.