Effects of removing low fresh leaf on the quality and economic characteristics of flue-cured tobacco

The objectives of this study were to investigate the effects of removing low fresh leaf on the chemical component, aroma composition, hierarchical structure and economic benefits of flue-cured tobacco. A field experiment was carried out to study the effects of four treatments - removing 0 (CK), 2 (T1), 3 (T2), 4 (T3) fresh leaves in lower part of the tobacco plant - on the chemical component, aroma composition, hierarchical structure and economic benefits of 'Yunyan 97' flue-cured tobacco in Wulong of Chongqing. The results indicated that with increasing number of removed fresh leaf, the contents of starch, total nitrogen and nicotine increased while K content decreased. Ratios of reducing sugar/nicotine and K/Cl in the upper and middle leaves of tobacco were significantly negatively correlated with the number of removed fresh leaf. However, the ratios of total nitrogen/nicotine of upper and middle leaves of tobacco were significantly positively correlated with the number of removed fresh leaf. For middle leaves, the highest content of aroma composition was in T2 treatment. However, the highest content of aroma composition for upper leaves was in T1 treatment. The economic benefits and hierarchical structure of flue-cured tobacco improved with different numbers of removed fresh leaves. The highest improvement was in T2 treatment, followed by T1 treatment and the lowest was in T3 treatment. Based on the comprehensive consideration of chemical components, aroma composition, hierarchical structure and economic benefits, it was recommended to remove lower fresh leaves in moderately fertile soils in Wulong ecological conditions. The number of leaf removal for the best effect on flue-cured tobacco was three.