Research On Applying Uniconazole To Cultivate Strong Seedings Of The Fluecured Tobacoo

As a kind of Chemical Regulators, Uniconazole have regulation on plant morphological built, carbon and nitrogen metabolism and enzyme activities.In this study,we studying for the effects of Uniconazole on seedling survival, growth and quality of flue-cured tobacco leaves from the aspects of Uniconazole concentrations, application methods, application of environmental temperature and application periods, Systematic analysis several technical factors of the method by use Uniconazole in tobacco floating-seedling. Research results are as follows:1. Uniconazole expressed inhibitory effects for plant high on tobacco seedlings, the higher concentration the stronger inhibition,and showed a Concentration effect of "low concentration effects in promoting high suppression" for fresh weight, dry weight of stem and leaf; played obvious promoting effect on tobacco seedlings, root dry weight, stem girth the root stem, and the effection with the increase of concentration showed the first increase and then decrease. In a word, Uniconazole have function to inhibited the seedling longitudinal growth of tobacco seedling, promote lateral growth and root growth.2. Uniconazole has a significant effect for chlorophyll accumulation, and the effect increases with the increased concentration; can significantly improve the seedling root vigor, the metabolism of carbon and nitrogen level, the antioxidant enzyme activity,conducive to root growth and development of tobacco seedlings, the carbon and nitrogen metabolism key enzyme activity and carbon and nitrogen metabolite levels and the enhance the resistance of tobacco seedlings.3. The efficacy of Uniconazole will be affected by the environment temperature, at the same concentration of Uniconazole, the effect will decrease with the temperature increasing; at the same temperature, the effect will show "low and high suppression" trend with the increase of concentration. Therefore, the use of Uniconazole concentration should be considered the ambient temperature conditions, when the environment temperature is in the range of13℃±21.5℃,5mg/L is more appropriate; when the environment temperature is in the range of21.5℃-30℃, suitable to10mg/L. 4. Regardless of leaf cutting or spraying Uniconazole, are conducive to promoting growth and seedling seedling formation; The application time of Uniconazole should be selected to growth in tobacco seedlings of "5leaves1heart", and the height should be reached about5cm; The method should be choice foliar application.5. It could cultivate strong seedlings by spraying Uniconazole,it also have strong effect to restore vitality for tobacco seedlings after transplanting. After spraying Uniconazole, the length of leaf was shortened, width, area and weight were increased, moisture content decreased. the contents of total sugar, reducing sugar, starch content increased, total nitrogen were content decreased, but the nicotine, potassium, chlorine content had no obvious change. The chemical composition changes also caused the change of chemical quality ratio for tobacco leaf, the sugar nicotine ratio increased, the ratio of nitrogen to nicotine decreased, two sugar ratio and the ratio of potassium to chlorine had no obvious change.