Abstract:

In order to provide a theoretical basis for improving ‘KRK26’ tobacco leaves quality through fertilization, the Dali ‘KRK26’ tobacco was selected to measure the contents of basic components in tobacco and soil, the quality characteristics of ‘KRK26’ and soil nutrient characteristics were evaluated, and the relationship was analyzed by using correlation analysis and stepwise regression analysis. The results showed that the content of reducing sugar and chloride of ‘KRK26’ was suitable, the aroma quality was delicate, the aroma was rich, the aftertaste was slightly sweet, and the flammability was good in tobacco leaves of Dali tobacco planting area. However, the content of total sugar and nicotine was slightly higher, the content of total nitrogen and potassium was slightly lower, and there was slightly irritating, dry and green impurities. The sensory quality score of ‘KRK26’ tobacco leaves in Dali was higher, but the content of total nitrogen was lower and nicotine was higher in 4 counties, meanwhile the content of total sugar of tobacco leaves was higher in Yangbi, Yunlong and Yongping, and the content of potassium was lower in Yongping. The contents of total phosphorus, available potassium and available boron in tobacco growing areas were deficient, and the contents of exchangeable magnesium in Yongping and Yunlong and the contents of organic matter and alkali hydrolysis nitrogen in Yangbi were deficient. At the same time, the total sugar of tobacco leaves was significantly negatively correlated with soil exchangeable calcium, and total nitrogen was significantly positively correlated with available phosphorus and exchangeable calcium. The aroma quality and aroma quantity of tobacco leaves were significantly positively correlated and negatively correlated with soil available potassium and organic matter, respectively. The irritation was significantly correlated with available phosphorus and total potassium. The miscellaneous gas and ash color were significantly positively correlated with trace elements in soil. Furthermore, the influence of soil organic matter on aroma was greater than the total phosphorus, and the effect of soil total potassium on irritation was greater than the total phosphorus, and both were direct negative effects. Therefore, the soil nutrients contributed greatly to the quality of ‘KRK26’ tobacco leaves were available phosphorus, total potassium, available potassium, organic matter, exchangeable calcium and exchangeable magnesium. It is suggested to increase the application of phosphate fertilizer, potassium fertilizer and suitable magnesium fertilizer on the basis of appropriate application of nitrogen fertilizer, pay attention to zinc fertilizer, boron fertilizer and reduce the application of calcium fertilizer, so as to improve the chemical composition coordination and smoking quality of ‘KRK26’ tobacco leaves.

Key words: Dali, flue-cured tobacco of ‘KRK26’, soil nutrients, chemical components, sensory quality, fertilization strategy, correlation analysis, stepwise regression analysis