Study on Harvest Maturity of Flue-cured Tobacco Based on Multi-index Fuzzy Comprehensive Evaluation

PurposeTo clarify the suitable harvest maturity of the upper tobacco leaves of Yunyan87 in Central Hunan Ningxiang tobacco area.

MethodsThree maturities of customary harvesting, delayed harvesting of 5 days and delayed harvesting of 10 days were designed, and the effect of harvest maturity on appearance quality, physical properties, chemical composition, smoking quality and economic properties of the upper flue-cured tobacco of the 11th to the 16th leaf position were studied. The fuzzy evaluation method was constructed by tobacco leaf appearance quality index, physical property index, chemical composition availability index, smoking quality index, economic effect index and comprehensive effect index were used to evaluate the effects of different harvest maturity.

Results1) Different harvest maturity had different effects on the quality of the upper flue-cured tobacco of the 11th to the 16th leaf position. 2) As the maturity of tobacco leaves increased, the single-leaf weight, thickness of leaf and weight per unit leaf area of flue-cured tobacco decreased, sugar content and nicotine content increased, and yield and output value increased. 3) Compared with the customary harvesting, the appearance quality index of flue-cured tobacco of the harvested delayed 5 days and 10 days increased by 8.58% and 15.08%, the physical property index increased by 0.92% and 0.18%, the chemical composition availability index increased by 18.61% and −8.04%, the smoking quality index increased by 6.67% and 6.40%, the economic effect index increased by 20.08% and 28.09%, and the comprehensive effect index increased by 7.76% and 7.49%, respectively. 4) The suitable harvesting maturity of upper leaves was: 50%-70% of the leaves became yellow, the main veins turned white, 50% of the branch veins turned white, some hairs fell off, the leaf margins were slightly curly, the tip was under the hook, and there were a few mature spots in the leaf surface.

ConclusionNingxiang tobacco area should increase the maturity of tobacco leaf harvesting appropriately, so as to improve the availability of upper tobacco leaves and increase tobacco farmers’ income.