Effects of nitrogen application amount and ratio of nitrogen to potassium on the growth and quality traits of Jiyuan flue-cured tobacco

Through field trials and laboratory analysis,the effects of different nitrogen application amount and ratio of nitrogen to potassium on the growth,single leaf weight,the middle leaves organic potassium index and neutral aroma constituents of flue-cured tobacco‘Zhongyan 100'were studied.The results showed as follows:1)Under the same application amount of nitrogen(75kg/hm2),the dry weight of the leaves,single leaf weight,middle leaves neutral aroma constituents in maturity stage increased firstly and then decreased with the increasing of the nitrogen to potassium ratio,but the organic potassium index of middle leaves decreased firstly and then increased.Under the same ratio of nitrogen to potassium(N∶K=1∶5),single leaf weight,the middle leaves organic potassium index and neutral aroma constituents increased firstly and then decreased with the increasing of nitrogen application amount,but the dry weight of theleaves in maturity stage keeping increaed.2)The treatments of 60kg/hm2 nitrogen,N∶K2O = 1∶5with 75kg/hm2 nitrogen,N∶K2O=1∶5could significantly simprove single leaf weight,potassium content and neutral aroma constituents of middle leaves,while the treatment of 60kg/hm2 nitrogen,N∶K2O = 1∶5could significantly improve the organic potassium index of middle leaves.3)Keeping the same ratio of nitrogen to potassium,and reducing the nitrogen application amount(from 75kg/hm2 down to 60kg/hm2),could control nitrogen,stable potassium,sulfur reduction,stable yields,and improve the quality of flue-cured tobacco in Wangwu tobacco growing area of Jiyuan.