| Tobacco black shank is a soil borne fungal disease caused by Phytophthora nicotianae,which is most likely to occur under tobacco continuous cropping and high temperature and high humidity climates.As it can affect the health of the tobacco plant,severely reduce the output,so takes great economic loss to the tobacco farmers.In the event of tobacco black shank soil,spread speed slow or quick,microbes have played a role.The results of the study are as follows:(1)We choose 4 strains of efficient inhibition beneficial microbial strains from planting flue-cured tobacco soil that infection tobacco black shank again,3strains were identified respectively as aspergillus Niger,extension penicillium and aspergillus smoke,another 1 strains was actinomycetes.Studies have shown that mixed strains are superior to single strains of anti-bacterial effect,Rb1,Rb3,Rb5,C5 mixed bacteria four strains of the most significant effect on the treatment of disease,mixed bacteria added to black shank pathogen cultivation,Phytophthora nicotianae silk weight is only 1.551g/L,4 kinds of single bacteria inhibitory effect was significantly better than the participants.Through the special process of these beneficial microorganisms into the organic fertilizer production process and a large number of breeding in order to develop anti tobacco black shank disease bio-organic fertilizer.(2)The study of fermentation technology showed that all of the 4 strains screened were aerobic bacteria.,and a large amount of oxygen was needed during fermentation,after the fermentation was 5~6d into steadily increased.The suitable growth conditions of the 4 strains:suitable growth temperature of 20?~35?,30?is the best;pH 4.0~9.0 value can grow normally,6.0~7.0 is the best;3 kinds of fungi can be mixed fermentation,actinomycetes fermentation time can be extended for 1 day after mixed with the other 3 species of fungi in the fermentation production to simplify the process,improve the efficiency.(3)The microorganisms used in the tobacco siol contain Rb1,Rb3,Rb5,and C5.Then observe the changes in the number of microorganisms in the rhizosphere soil and the non rhizosphere soil.The bio-organic fertilizer on tobacco black shank disease prevention effect is very significant.The previous crop is rice incidence rate of less than 2%,0.5%lower more than the control;the previous crop is corn incidence rate of less than 3%,0.5%lower more than the control.Through the application of bio-organic fertilizer could control tobacco black shank disease,at the same time also promoted the changes in the number of soil microorganism,rhizosphere soil microbial activity increased significantly,soil micro ecological environment restoration and balance.(4)The field experiment showed that,use the bio-organic fertilizer on the growth of tobacco plants have a positive effect,it can significantly reduce the incidence of disease,tobacco can rapid absorption of soil fertilizer,promote tobacco plant growth and development.The survey found that use bio-organic fertilizer could increase the number of soil microbial populations,and the number of microorganisms in the soil increased significantly.When the flue-cured tobacco matures,the pH value of soil increased,while T2,T3,T4 were stable at 6.3,5.8,6.8,but T1decreased to 4.5.The number of bacteria in T2,T3,T4 rhizosphere soil was 1-3 times higher than that of the control T1 in the mature period,and the number of actinomycetes and fungi was lower than that of the control T1.When the flue-cured tobacco matures,Soil alkali hydrolyzable nitrogen during,T2,T3,T4 three treatments were higher than the control T1.When flue-cured tobacco mature,the content of available potassium in tobacco field T4 was significantly higher than that of the control,The other treatments were close to the control.T2 was slightly lower than that of the control,T3 and T4 were all higher than those of the control.The intrinsic chemical composition of tobacco detection found that the use of bio-organic fertilizer,the intrinsic chemical composition tends to coordinate,improve the internal quality of tobacco leaf,Liangshan sweet scent style is more obvious.In the internal chemical composition of flue-cured tobacco,only the total sugar content is about 5%higher than that of the reference value,and the other internal chemical components are within the range of high quality tobacco chemical components.Tobacco rhizosphere microbial propagation effects of soil pH,microorganism,soil fertility greatly.If soil fertility equilibrium,microbial active plants provide more nutrients can be absorbed,the healthy growth of plants to provide better conditions for microbial propagation,the two mutual benefit.(5)The field demonstration results show that the use of bio-organic fertilizer for tobacco agronomic traits of each treatment is slightly better than that of control,some agronomic traits in different model Township,reached a significant level.Tobacco black shank prevention effect is generally better,part of the township reached significant level,the individual control effect is not significant towns need to further explore the reasons.Field demonstration bio-organic fertilizer for flue-cured tobacco YN85 and YN87,tobacco black shank model Township controleffect in33.54%~94.80%.The investigation of tobacco economic benefit by using bio-organic fertilizer,increased by 45.2~159 yuan/667m~2.However,soil improvement is a long process,in order to better control of tobacco black shank,bio-organic fertilizer need long-term application of antagonistic bacteria containing,improve soil micro ecological environment,promote the restoration of soil structure,plant nutrient uptake,improve their role in disease resistance of tobacco plant,reduce the use of chemical fertilizers and pesticides,to restore soil health. |
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