Accumulation Rule of Nicotine in Sun-cured Red Tobacco and Effects of Different Fertilizer Application Amounts on Nicotine

[Objective] The aim was to discuss the accumulation rule of nicotine in sun-cured red tobacco and effects of different fertilizer application amount on nicotine.[Method] With Yanshai 5 as tested variety,phosphorus nitrate,diammonium phosphate and potassium sulfate as tested fertilizers,the effects of different fertilizer application amount on nicotine were studied.[Result] Nicotine in sun-cured red tobacco started to accumulate rapidly since 50 d after transplanting.The highest value of nicotine daily accumulation amount in leaf and root all appeared on the 60th day after transplanting and that in stem appeared on the 70th day after transplanting.Nicotine in tobacco leaf was highest,that in stem was next and that in root was least.There was no obvious change on the proportion of nicotine in tobacco root,stem and leaf between earlier growing stage and late growing stage.Under the same condition of fertilization level,the nicotine content was upper leaf middle leaf lower leaf and the total sugar content was middle leaf upper leaf lower leaf.Under the different fertilization level,the total sugar content was decreased with the increment of nitrogen application amount and the nicotine content was increased with the rising of plant parts.[Conclusion] The research provided the scientific basis for the production of sun-cured red tobacco.