Abstract:

To explore the effects of tobacco stem biochar based fertilizer application on yield, quality and disease occurrence of flue-cured tobacco, flue-cured tobacco varieties ‘Honghuadajinyuan’, ‘K326’ and ‘Yunyan 87’ were used as the research objects, and one conventional fertilization treatment (CK) and three different application rates of tobacco stem biochar ( T₁: 400 g/plant, T₂: 500 g/plant and T₃: 600 g/plant) were set up to determine the growth period, agronomic traits, incidence rate, economic traits and chemical composition of flue-cured tobacco with different varieties and treatments. The results showed that: (1) compared with the control treatment, the application of biochar-based fertilizer could prolong the growth period of flue-cured tobacco ‘Honghuadajinyuan’, ‘K326’ and ‘Yunyan 87’, and significantly improve the plant height, stem circumference, effective leaf number, maximum leaf length and leaf width of flue-cured tobacco. The application amount of 600 g/plant for ‘Honghuadajinyuan’ and the application amount of 500 g/plant for ‘K326’ and ‘Yunyan 87’ had the best effect. (2) The incidence of tobacco mosaic disease, wildfire disease and climatic spot disease treated with biochar-based fertilizer was significantly lower than that of the control treatment. Among them, the incidence of tobacco plant disease was the lowest when the application amount for‘Honghuadajinyuan’ and ‘K326’ was 600 g/plant and the application amount for ‘Yunyan 87’ was 500 g/plant. (3) The yield, average price, proportion of medium-grade tobacco and output value of tobacco treated with biochar-based fertilizer were significantly higher than those of control, and the application of 600 g/plant for ‘Honghuadajinyuan’, 500 g/plant for ‘K326’ and ‘Yunyan 87’ had the best effect on improving the quality of tobacco plants. (4) After the application of biochar-based fertilizer, ‘Honghuadajinyuan’ could significantly reduce the content of total sugar and reducing sugar in tobacco leaves, and made the content of total nitrogen, potassium oxide and water-soluble chlorine in tobacco leaves more suitable. ‘K326’ and ‘Yunyan 87’ could significantly reduce the content of total sugar, reducing sugar, total nitrogen, nicotine, potassium oxide and water-soluble chlorine in tobacco leaves. The content of chemical components in tobacco leaves was the most suitable when the application amount for ‘Honghuadajinyuan’ was 600 g/plant, the application amount for ‘K326’ and ‘Yunyan 87’ was 500 g/plant. In summary, the application of 600 g/plant for ‘Honghuadajinyuan’, 500 g/plant for ‘K326’ and ‘Yunyan 87’ biochar-based fertilizer had the best effect on the growth of tobacco plants.

Key words: flue-cured tobacco, tobacco stem biochar based fertilizer, agronomic traits, production quality, chemical composition