Effect of plant density and remained leaves number on agronomic traits and quality of flue-cured tobacco.

The flue-cured tobacco variety Yunyan87 was selected to study the effect of different plant densities and remained leaves number on the agronomic traits and the chemical composition of flue-cured tobacco by a field split block experiment design.The results indicated that the plant density and the remained leavers number had a significant impact on the single-leaf weight,yield,output and the above-average leaves percentage of flue-cured tobacco,but the interactive effect of the plant density and the remained leaves number on the output and the above-average leaves proportion of flue-cured tobacco was highly significant.The total nitrogen,protein and nicotine content of flue-cured tobacco were decreased with the increase of plant density,but the total sugar and the chlorine content were increased.The total nitrogen,the nicotine content and the potassium content were decreased with the increase of remained leaves number,but the total sugar content was increased.Moreover,the interactive effect of the plant density and the remained leaves number on the total nitrogen,the protein and the nicotine content was highly significant.The group structures for the treatment of 13 500 plants per hm2 and 22 leaves per plant was reasonable and the quality of the flue-cured tobacco was better.