A Study On Potassium Fertilizer Topdressing And Spraying Effect On The Quality Of Flue-cured Tobacco

Directed against a prominent problem that with potash fertilizer not in full use in the production of flue-cured tobacco in China, tobacco leaves contain a relatively low potassium, experimented with K326cultivars in Luliang County, Qujing city of Yunnan province, choosing a soil that is of medium fertility and is convenient to irrigate, drain and rotate as its study plot, this essay conducts two experiments: potassium fertilizer root topdressing and spraying so as to find a best solution, and determines the optimal potassium fertilizer root topdressing proportion, topdressing stage and foliar potassium period, and provides some clues for further study on the potassium in tobacco leaves. The main conclusions are as follows:1. During production, applying potassium fertilizer at different times produces influence of different degrees on plant height, leaf length, leaf width, leaf number and other agronomic traits. Applying potassium fertilizer in the budding stage or after topping can reduce the thickness of the upper leaves, make upper leaves structure become loose and ductile and increase the usability of upper leaves. Applying after topping gains a greater effect than in budding stage or15-25d after transplanting.In the case of equal amount of potassium fertilizer, root potassium with60%+40%as base fertilizer and topdressing proportion,1times irrigation (15-25d)+1topping day irrigation (2Two half and half) is the most high potassium content in tobacco leaves,the more amount of potassium content, the more effects it has on the amount of potassium in the upper and middle part of the tobacco. Compared with totally applying with base fertilizer, applying at different stages can reduce the content of total nitrogen in upper leaves. And the more times there are, the more noticeable its effects will be. Applying root potassium at different growth periods decreases the amount of chlorine in upper and middle parts of tabacco and the amount of nicotine in different parts of tobacco.2. The spraying of flue-cured tobacco in different growth periods has no big influence on maximum leaf length, leaf width, plant high, leaves number and other agronomic traits, with no obvious rules or difference. In the physical traits, the spraying process has a certain impact on tobacco leaf length, leaf width, stem ratio, reduces the upper leaf thickness, makes leaf tissue structure become loose and ductible, and thus increases its usability, In different leaf position, effects of spraying potash times and spraying time on the content of potassium content of tobacco leaves of flue-cured tobacco are maximum, then the middle leaves, lower leaves little effect, In the spraying time, effects of topping the spraying of potash fertilizer on flue-cured tobacco potassium content is biggest, followed by squaring stage spraying, the rosette stage spraying of potash fertilizer has little effect on tobacco. Foliar application of potassium fertilizer can reduce the content of total nitrogen, chlorine in tobacco leaves, the more times spraying potassium there is, the more remarkable the effect is. Effects of different treatments on flue-cured tobacco, nicotine content in the middle of showing a regular:topping day> squaring stage> the rosette stage.3. From the soil fertility condition, unique in zhaokua town, Luliang, root potassium with60%+40%as base fertilizer and topdressing proportion,1times irrigation (15-25d)+1topping day irrigation (2Two half and half) or potassium potassium foliar spray treatments with topping stage and squaring stage Spraying Potassium treatment, tobacco plant will develop earlier and grow faster at the early stage, and muture well at the late stage; and besides, its leaves are of nice appearance and good maturity; upper leaf loose degree, percentage of stem, balanced moisture content are better than the otherwise treated tobacco samples; there is a high potassium content in tobacco leaves, an appropriate total nitrogen and reducing sugar content, and a low content of chloride, nicotine of upper leaves of flue-cured tobacco. The internal chemical composed with good coordination, the overall quality has been developed toward a good direction.