Study On The Technique Of Flue-Cured Tobacco Seedling Production In The Float System

The experiment was to study the effect of medium and the effect of three nutrient elements (nitrogen, phosphorus and potassium) on the flue-cured tobacco seedling by the optimum compound design (311-A). The optimum formula of nitrogen, phosphorus and potassium was put forward on computer. At the same time, the experiments were to study the effect of clipping the leaves of seedlings and compare the two ways of tobacco seedlings production. The results are summarized as follows:1. As a main ingredient of flue-cured tobacco float breeding substrate, bagasse must be thoroughly decomposed. Or it would reduce the gemination rate and seedling rate of flue-cured tobacco. When bagasse : pearlite : sand = 6:3:l(v/v), flue-cured tobacco seedling growed well.2. With in eleven treatments, the eleventh treatment's breeding germinated orderly, growed evenly and the gemination rate and seedling rate were high. The agronomic properties were excellent. Roots activity were vigorous, restrained water / free water, soluble sugar and Vc content were high. At a certain range of concentrations (within -2-2 levels), mutual effects of nitrogen, phosphorus and potassium on all indexes of seedlings can affect them positively. Regressive analysis showed that the optimal project of fertilizing nitrogen, phosphorus and potassium was: N 176.4 mg/L, P2O588.22 mg/L and K2O 197.2 mg/L. And thenN:P2O5:K2Ol:0.5:1.12.3. The fresh weight of roots, roots/shoots, the roots activity, the rootsnumber and stem diameter were much more significant than not having beenclipped leaves. Clipping leaves could promote the growth of seedlings andenhance the rate of available seedlings.4.Float breeding tobacco seedlings were much better in comparison withtraditional raising seedlings in quality. In cost, 35 manpowers could beAenough to accomplish the breeding in the float system on 1 hm farmland (This could be decreased by 60%). The cost of material, fertilizer and pesticide, etc. was about RMB ?34 (The cost of traditional raising seedlings was RMB ?25). The area was 30 m2 (105 m2 in traditional raising way).