Abstract:
The effects of the interaction between planting density and nitrogen application rate on neutral aroma component contents and smoking quality of upper leaves was studied with Yunyan 87 as the sample variety using a split-plot experiment design and the data was ananlyzed using variance analysis, significance test, partial correlation and other methods. The results showed that both planting density and nitrogen application rate had significantly positive correlation with neutral aroma component contents. The interaction of planting density and nitrogen application rate had a greater influence on the enhancement of neutral aroma component contents, especially in the following four treatment combinations including high density high nitrogen, high density medium nitrogen, medium density high nitrogen and medium density medium nitrogen, all of which significantly improved the total aroma content of the upper leaves. Partial correlation analysis showed that planting density showed a significantly negative correlation with smoking quality. Low and medium planting density, in combination with both low nitrogen application rate and high nitrogen application rate could promote smoking quality. Compared with the comprehensive assessment of different combinations of treatments, the results indicated that the treatment combination of medium density, high nitrogen was the best and most appropriate combination in neutral aroma component contents and smoking quality, the treatment combinations of low density high nitrogen, low density medium nitrogen, high density high nitrogen and high density medium nitrogen were the next, and the treatment combination of high density low nitrogen was the worst compared with the other treatments. Comparison between different treatment combinations revealed that the influence on neutral aroma component contents and smoking quality was significantly different among interactions of different planting densities and nitrogen application rates.