Abstract:

In order to clarify the effects of topping time and topping method on the yield and quality of flue-cured tobacco, a field experiment was carried out in Guiyang, Chenzhou. The experiment was the two-factor split-plot test, and set C1 (topping at budding), C2 (topping at the opening of the central flower), C3 (topping at the opening of the full flower) and D1 (removing the flower without young leaves), D2 (removing the top adjacent 2 young leaves on the flower), D3 (removing the top 4 adjacent young leaves on the flower). The effects of different treatments on the economic traits, physical characteristics, chemical composition and sensory quality of flue-cured tobacco ‘Yunyan 87’ were analyzed. The results showed that with the delay of topping time, the proportion of superior tobacco, average price, yield, output value and smoking quality of flue-cured tobacco increased first and then decreased. The length, thickness and leaf area quality of upper leaves increased, and the contents of total nitrogen and nicotine increased. With the increase of young leaves removed by topping, the proportion of superior leaves increased first and then decreased, while the output value decreased first and then increased, and the length, thickness and leaf area quality of upper, middle and lower leaves increased, the leaf area index of middle leaves increased, and the contents of nicotine, total sugar and reducing sugar increased. Under the interaction of topping time and topping method, the economic traits of the treatment of topping without removing young leaves when the central flower was open were the best, the physical characteristics of the treatment of removing the top adjacent 4 young leaves on the flower when the bud was open were the best, and the sensory quality of the treatment of removing the top adjacent 2 young leaves on the flower when the central flower was open was the best. Therefore, it is more than suitable for ‘Yunyan 87’ to remove the top adjacent 2 young leaves on the flower when the central flower is open.

Key words: flue-cured tobacco, topping time, topping method, economic traits, quality of tobacco leaves