Nitrogen is one of the most important nutrients affecting the growth, yield, and quality of flue-cured tobacco. The main nitrogen absorbed from soil by flue-cured tobacco is nitrate nitrogen and ammonium nitrogen, and flue-cured tobacco absorbs these two forms of nitrogen. Assimilation and effects on carbon and nitrogen metabolism. In the current production of flue-cured tobacco, due to the large amount of nitrogen fertilizer applied, the soil in the flue-cured tobacco still contains a large amount of nitrogen, which makes the flue-cured tobacco absorb a large amount of nitrogen from the soil in the later stage of growth, eventually leading to tobacco, especially the upper leaves, nicotine and protein. The excessively high content of nitrogenous compounds will seriously affect the quality of tobacco leaves, and ultimately affect the yield, quality, yield and average price of flue-cured tobacco. It is of great practical significance to produce quality flue-cured tobacco in future production practices.
Nitrogen nutrition can adjust the value of tobacco chlorophyll index, leaf color, intrinsic chemical quality and aroma quality in a wide range. There was a correlation between nitrogen nutrition and leaf chlorophyll content, color, intrinsic chemical quality and aroma quality, while chlorophyll content decreased with the increase of leaf area and maturity. Flue-cured tobacco should be sensitive to changes in nutrients and changes in surrounding environmental conditions. When nutrients are visible to the naked eye, they will have a great impact on the yield, quality, and commercial availability of tobacco leaves. In order to obtain high-yield and high-quality tobacco, the leaf color change of flue-cured tobacco leaves is usually used as an important indicator of nutrition management, tracking of tobacco nutrient status and judgment of tobacco leaf maturity. Therefore, it is necessary to quickly understand the nitrogen status of tobacco plants in real time.
Traditional testing methods require a lot of manpower and material resources in sampling, measurement, data analysis, etc., and their timeliness is poor. Due to the close relationship between chlorophyll and nitrogen status, chlorophyll can be used to reflect the nitrogen status of the plant. At present, spectral analysis technology has been greatly developed and applied for non-destructive testing of nitrogen nutrition diagnostic technology. The chlorophyll meter method is an effective method for rapid and in vivo non-destructive detection of leaf relative chlorophyll concentration in field.
Chlorophyll meter can be selected in every part of the leaf when measuring tobacco leaf, but from the viewpoint of stability and operability, the best location of the flue-cured tobacco is the middle part of the leaf. In the measurement, tobacco was also found to be planted in rows. Different chlorophyll values ​​extending to the same leaf position were also significantly different. Therefore, it is better to use the leaf in the upper part of the upper part when measuring. If you compare the leaves of a certain leaf position, you should try to take the same direction. At the same time, you should increase the sample reading point because of the larger leaf area of ​​a single leaf. The expert experiment showed that the effect of nitrogen fertilizer on the chlorophyll value of tobacco leaves was greater than that of varieties.
The chlorophyll meter values ​​vary according to different years, locations, different nitrogen levels, different leaf positions, and different parts of the same leaf. There is a stable pole between chlorophyll value and chlorophyll concentration, chlorophyll meter value and total leaf nitrogen concentration. Significant correlation.
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