Studies Of Technique Of Improving Tobacco Seedlings Quality In The Floating System

In 2005, Taking Zhongyan101 and K326 coated seeds as materials, and using commericial medium and fertilizers producted by Yexian County floating system materials factory and raw medium materials producted by Ruzhou tobacco company, technical application which would effect tobacco seedlings quality in the floating system were studied. The result were as follows:1 Influence of seedling shed standards on growth and development of tobacco seedlings in the floating systemSeedling shed standards affected obviously growth and development of tobacco seedlings in the floating system. Tobacco seedlings' growth trend of the largest and middle seedling shed were better than the smallest. The physiological characteristics of the laragest seedling shed have little difference with the middle seedling shed, but the stem lenghth and stem circumference of largest shed were higher than the middle shed, and root volume, root dry weight and the numbers of first and second order lateral root of the middle shed was highest. Results showed that small shed standard was disadvantageous to growth and development of tobacco seedlings.2 Influence of plug-and-transfer and direct-seeded options on growth and development of tobacco seedlings in the floating systemPlug-and-transfer obviously decreased tobacco's botanical characteristics, root activities and the content of water-soluble protein in the earlier seedbed stage. After transplanting, difference of underground botanical characteristics of plug-and-transfer and direct-seeded were lessened after transplanting, botanic characteristics of overground, root activities, NR activities and content of water-soluble protein of plug-and-transfer seedlings gradually surpassed the direct-seeded seedlings. Obviously, plug-and-transfer was disadvantageous to seedlings' growth at seedbed stage. After transplanting, plug-and-transfer increased some physiological characters and had fewer effects to other characters.3 Comparison of soil-bed and water-bed on growth and development of tobacco seedlings from seedbed stage to three weeks after transplantingThe botanical characteristics of tobacco seedlings of floating system were better than of soil-bed at seedbed stage. From later seedbed stage to after transplanting, the contents of...