Optimization of key cultivation techniques for flue-cured tobacco in western Henan on aroma component contents and sensory evaluation

To establish optimal cultivation measures for flue-cured tobacco in western Henan, an L₉(3⁴) orthogonal experiment was conducted to study the effects of nitrogen rate (1.5-3.5 kg/667 m²), planting density (900-1 100 plant/667 m²) and number of residual leaves (18-22 piece/plant) on the content of neutral aroma components and sensory evaluation of cv. LY1306. Single-factor analysis showed that the total content of neutral aroma components and sensory performance increased first then decreased with the decrease of nitrogen rate and planting density. With the increase of number of residual leaves, the total content of neutral aroma components decreased first then increased, while sensory evaluation outcome was on the opposite. A two-factor interaction analysis indicated that the interaction effect between the number of residual leaves and the nitrogen rate influenced the total content of neutral aroma components and sensory evaluation most significantly, and there existed a maximum in this experiment. Mathematical models for neutral aroma components and sensory evaluation were used to simulate and optimize the parameters separately, the results showed that when planting density, number of residual leaves and nitrogen rate were 1 003 plant/667 m², 22 piece/plant and 2.728 8 (or 2.282 4) kg/667 m² respectively, the total content of neutral aroma components and sensory performance reached their maximum, which suggested that this combination was the optimized combination for producing quality tobacco leaves in tobacco-planting soils with high/moderate fertility in western Henan.