Study On The Improvement Of Tobacco Seedling Technology In Liangshan

Flue-cured tobacco is planted as an important economic crop in LiangShan,SiChuan province.Because of the complex terrain and environment,the seedling technique used in this region is relatively out of date.Through integration with the methods of seedling test and field test,this paper is conducted to investigate the effects of the different densities of seeding plate,different seeding techniques and the new nursery substrate on the flue-cured tobacco.Based on the effects on the growth period,quality of seeding and the physiological property of the flue-cured tobacco,the key issues,including the ratio of the new matrix,the optimal revamp of the seeding plate and the optimization of the seeding technique in LiangShan,can be preliminarily defined.The main results can be summarized as follows.1.The tobacco seeding planted by the optimized seeding plate with 160 holes and 209 holes has strong growth potential,and the biomass,root white,the thick and of the tobacco seeding are all bigger than those of the comparison results.The dry weight of stem and leaf of the tobacco seeding planted by the seeding plate with 160 holes are respectively 48.85%and 146.65%higher than those of the comparison results and the small seeding plate,the corresponding results of dry weight of the root are respectively 88.20%and 127.65%higher,the root volumes are 43.75%and 76.92%higher,respectively.The corresponding results about the seeding plated with 209 holes are 37.84%and 128.42%,72.77%and 108.99%,31.25%and 61.54%respectively.2.The tobacco seeding planted by the optimized seeding plate with 160 holes and 209 holes has good capabilities of root absorption,and the root activity of the tobacco seeding is obviously better than that of the comparison results.The root activity of the tobacco seeding plated by the seed plate with 160 holes(new specification)is 20.99%higher than that of the ones plated by the seed plate with 160 holes(CK).The corresponding result of the 209 holes(new specification)is 22.81%higher than that of the 286 holes(CK).3.The tobacco seeding nurtured by the wet tray seeding will grow fast after the grand cross period,whereas its growth time would be shorter than those nurtured by the traditional seeding and floating seeding,nine days and six days shorter,respectively.From the aspects of the stem length and girth,the differences of the stem length between the tobaccos nurtured by the wet tray seeding and floating seeding are small,whereas the stem girth nurtured by the wet tray seeding would be 16.55%higher than that of the ones nurtured by the floating seeding.The difference between the numbers of leaves under the wet tray seeding and floating seeding is not significant,whereas the leave numbers under the two seeding methods would be 1.16 and 0.79 piece more than the ones under the traditional seeding.The length and width of the leaf under the wet tray seeding is largest than the other seeding methods,the length and width of the leaf under the floating seeding is the second largest.The fresh weight of the rhizomes leaf nurtured by the wet tray seeding would weigh up to 10.22g,whereas its dry weight would be 0.595g.The dry and fresh weight of the rhizomes leaf nurtured by the wet tray seeding would be 1 time heavier than those nurtured by the floating seeding and the traditional seeding.Thus it can be concluded that the overall quality of the tobacco seeding nurtured by the wet tray seeding would be better than those nurtured by the floating seeding and the traditional seeding.4.The results showed that the photosynthetic rate of wet seedling was significantly higher than that of floating seedlings and conventional seedlings,which were 0.17 times and 0.78 times respectively.The stomatal conductance was slightly larger than that of floating seedling and control,and there was no significant difference between floating seedling and control,and transpiration rate was not significant.There was a significant difference between the active absorption area and total absorption area of the root system of each treatment,among which the total absorption area was the highest,followed by floating seedlings.5.The environmentally friendly nursery substrates that matching Water retention agent and clay as 7:3,can balance the permeability of nursery substrates and the different needs of water-stable aggregate in management of dry-wet.The tobacco seedlings growths robust,especially root development,strongly root activity,and increase disease resistance.At the same time can get environmental friend,remarkable,benefit.