Studies Of Production Techniques And Development Of Low Residual High Quality Flue-cured Tobacco In Wulian Mountain Region

Tobacco, as a kind of special industrial crop, was confronted with the dual pressure of WHO and WTO. The safe quality and production environment of tobacco leaves were of importance to the people's health, the export of tobacco products and sustainable development of tobacco agriculture. In order to reduce the level of residue of pesticides and heavy metals in tobacco leaves, improve tobacco leaf quality and protect the environment of planting tobacco, we use the methods of data investigation, sample survey and field experiments, to study and develop the production techniques of low residual high quality flue-cured tobacco in Wulian Mountain flue-cured tobacco region. The main results were as follows:1. The status and related regulations of Wulian Mountain low residual high quality flue-cured tobacco were defined. Studies on low residual high quality flue-cured tobacco should not only accord with the international practice and the relevant regulations of nation and region, but also accord with the special requirement in tobacco industry. Thus, it was necessary to establish producing area standard, producing technical regulations, product standard and package standard, to establish the production bases of certain scales with the authentication of relevant organization and to establish an integrated production system.2. It was suitable to develop low residual high quality flue-cured tobacco in Wulian Mountain region. The soil has two types, i.e., brown soil and cinnamon soil. In soil, the contents of N and Cl were moderate, the potassium was abundant, Mn, Cu and B contents were above the moderate. The soil organic matters, P and Mg contents were all low, and Zn was relatively low. As a whole, this region was suitable to produce high quality tobacco leaves. In the soil of 17 villages of 3 towns (Xumeng, Chaohe, Wanghu) in Wulian, Pb, Cd and Hg contents were under the soil background level, and benzahex and DDT contents were also under the soil background level. It indicated that this area was unpolluted and it had excellent soil conditions to produce low residual tobacco leaves.3. Tobacco leaf quality in Wulian region was satisfactory, and the measures to further improve tobacco leaf quality in Wulian region was put forward. The organic chemical composition of tobacco leaf in Wulian was relatively balanced. There were low Mg content and moderate Cl content in tobacco leaves. With typical middle fragrance type, moderate strength, medium thickness or partially thick, preferable fragrance quality, ample fragrance quantity, pure residual taste, and some unpleasant sense, overall appraisal about tobacco quality in Wulian region ranges from moderate to better. The smoking quality had the further potential to be improved, especially in their fragrance and taste. According to characteristics in soil and tobacco quality of Wulian, in order to improve tobacco quality, it was necessary to increase the application of organic fertilizers and cake fertilizers, to supplement Mg and P. The tobacco population structure should also be adjusted as well as the postponement of topping properly in tobacco production, in order to further improve tobacco quality.4. To apply the compost mainly of swine waste could improve tobacco leaf quality, and intercropping between tobacco and potato could increase the comprehensive economic benefits of tobacco fields. The compost composition and the ratio, and the improvements of intercropping between tobacco and potato were clarified. The tobacco comprehensive technological measures were established preliminarily.5. The applying actuality of pesticides in Wulian region was found out, and the top allowable limit standard of pesticide residues including organic Cl, organic P, etc. and the heavy metal limit standard in Wulian low residual high quality tobacco leaves were examined and established.