Effects Of Garlic Root Decomposition On Harmful Fungi And Flue-cured Tobacco Growth In Tobacco Growing Soil

Liangshan is one of the main tobacco producing areas in China.Garlic to flue cured tobacco is one of the important planting patterns.Garlic straw and root residue decomposition have allelopathic effects and have a certain effect on the growth of stubble crops.There are few studies on the effects of garlic root decomposition on tobacco field soil and flue-cured tobacco production.In this paper,we prepared garlic root decomposition with different decomposing time and studied its effects on tobacco black shank through indoor cultivation.We set three processes including the treatment of winter leisure to flue-cured tobacco,garlic treatment to flue-cured tobacco and garlic root decomposition to flue-cured tobacco to study their effects on the tobacco field and the production of flue-cured tobacco in the field experiment.The results are as follows:1.Prepared garlic root decomposition with different decomposing time?0 d,5 d,10 d,15 d,20 d,25d,30 d?to study its inhibition of tobacco black shank.Garlic root decomposition with different decomposing time could inhibit the growth of tobacco black shank fungus,and the inhibition rate was3.90%-51.29%,and garlic root decomposition that decomposed 15 days had the best inhibition effect.Treated by garlic root decomposition that decomposed 15 days,myceliun appeared hyphae deformation,hyphae branch and protoplasm leak.Pot experiments showed that the control effect of garlic decomposition solutions decomposed in different times on tobacco black shank was to 4.3%-47.63%in ninth days after the transplanting of Flue-cured Tobacco.The results showed that garlic root decomposition had a good inhibitory effect on tobacco black shank,and had better control effect on tobacco black shank.2.Compared with the control,the ammonium nitrogen and nitrate nitrogen in the tobacco field soil treated with the former garlic and the former garlic root decomposition were all increased by 0.19mg·kg^-1?8.25 mg·kg^-11 and 0.39 mg·kg^-1?0.73 mg·kg^-1,but the ammonium and nitrate nitrogen content of the two treated tobacco fields decreased after the harvest.Compared with the control,the effective phosphorus and soluble organic carbon content in the soil of the tobacco field treated with garlic and garlic root decomposition were increased in different degrees when the flue-cured tobacco was transplanted and harvest.The solutions of garlic and garlic root decomposition could increased the activities of invertase,urease and phosphatase in soil.It could concluded that the former garlic and garlic root decomposition could improve the soil fertility conditions of tobacco fields.3.In the treatment of garlic root decomposition,the dry matter accumulation in flue-cured tobacco roots,stems and leaves was increased by 1.20%,3.77%,0.43%and 8.09%,89.65%,93.39%in thirtieth days and sixtieth days after the transplanting of Flue-cured Tobacco.It played a significant role in promoting the growth of flue-cured tobacco in the long term.Garlic treatment could also promote the growth of flue-cured tobacco to some extent.The proportion of upper grade tobacco,the proportion of middle and upper grade tobacco,yield,output value and average price of the former garlic and garlic root decomposition were increased to a certain extent.Pretreatment of garlic and pretreatment of garlic root decomposition had no significant effect on tobacco quality.4.During the transplanting period of flue-cured tobacco,the dominant bacteria in different treatments were sordariomycetes,dothideomycetes and chytridiomycetes.Compared with the control,former garlic and garlic root decomposition treatments increased the dothideomycetes of tobacco soil by63.70%and 73.45%respectively,former garlic and garlic root decomposition treatments decreasd the chytridiomycetes and sordariomycetes of tobacco soil respectively.In the harvest period of flue-cured tobacco,the dominant bacteria in the control group and the former garlic root decomposition were sordariomycete,dothideomycetes,eurotiomycetes.The dominant bacteria in the soil treated with garlic were sordariomycetes,dothideomycetes and chytridiomycetes.Compared with the control,the pretreatment of garlic and the garlic root decomposition decreased the sordariomycetes and eurotiomycetes in tobacco field soil,but the dothideomycetes increased by 10.95%and 1.53%respectively.Compared with the control,the chytridiomycetes of the former garlic treatment increased by 41.43%,but the chytridiomycetes in the soil treated with the garlic root decomposition was reduced by 8.32%.The results showed that the pretreatment of garlic and the garlic root decomposition could increase the beneficial fungi related to soil inhibition of soil borne diseases,reduce the related harmful fungi,they also could increase the number and diversity of the fungi in the soil and change the structure of the microbial colony of fungi in the tobacco field.