Study on Dynamic Accumulation of Dry Matter During Flue-cured Tobacco Growth Period in Field

[Objective] The study aimed to explore dynamic change of dry matter accumulation of flue-cured tobacco and provide theoretical basis for it's cultivation and management.[Method] Through experiment of 2 years and 7 sites,the dynamic change of dry matter accumulation of 8 flue-cured tobacco varieties in field was studied.[Result] The dynamic change of dry matter accumulation of different flue-cured tobacco varieties in field could be simulated by Logistic curve regression equation and their correlation coefficients were at significant level,but the dry matter ultimate amount of flue-cured tobacco,the biggest accumulation rate and its appearing time varied with varieties and years.The process of dry matter accumulation in flue-cured tobacco could be divided into three stages: pre-stage,mid-stage and late-stage,and the contribution rates in various stages to dry matter accumulation were 12.00%,68.71% and 19.29% resp.There was a close relation between dry matter of flue-cured tobacco and yield.From 55 d to 70 d after transplanted,there had the largest contribution rate to dry matter accumulation in tobacco plant.About 80 days after transplanted,the total weight of dry matter,the root to shoot ratio and the part of the ground had largest correlation with yield.[Conclusion] The cultivation and management of flue-cured tobacco in field should be strengthened to insure enough dry matter accumulation from 55 d to 70 d after transplanted so as to get good quality and high yield of flue-cured tobacco.