Research And Preparation Of The Combined Soluble Liquid Agent Of 4.5% Propamidine And Chitosan

Propamidine,which have novel effect on grey mould caused by Botrytis cinerea,is a type of fungicide with intellectual property in China and it is safe to environment.Early research result showed that 8:1(mass ratio)was considered as the optimal ratio of propamidine and chitosan This paper focused on the combination of propamidine and chitosan,by using wood vinegar as the dispersion medium formulation of 4.5%propamidine-chitosan soluble liquid agent(SL)was determined.On this basis,three pathogenic fungis:Botrytis cirerea,Fusarium oxysporum and Pseudoperonispora cubensis were used for a series of bioactivity assays.The main results can be briefly described as follows:1.The optimal formulation of 4.5%propamidine-chitosan SL was determined through the selection test of aiding solvent,surfactant and the physical and chemical properties of the formulation can meet the standards.The results are as follows:Propamidine 4.0%(mass fraction,same as follows.)Chitosan 0.5%NP-10 8%Dimethylsulfoxide 5%Ethanol 15%Butyl acetate 15%Citric acid 13%Wood vinegar To 100%2.The quality detection method of 4.5%propamidine-chitosan SL was set up by HPLC and UV spectrophotometry.The results demonstrated a good linear relationship between response value and concentration in addition the method was was correct and credible.3.Using Botrytis cirerea,Fusarium oxysporum and Pseudoperonispora cubensis as test objects,in vitro toxicity of 4.5%propamidine-chitosan SL and the two single chemicals were tested.The results indicated that propamidine mixed with chitosan 8:1 showing significant synergism to the 3 plant pathogenic fungus.4.The in vivo results of 4.5%propamidine-chitosan SL against the 3 plant pathogenic fungus showed that:at the concentration of 225 mg/L,the sample showed good protective and therapeutic effects against Botrytis cirerea,tissue test effects were 78.06%and 61.21%,pot test effects were 51.36%and 58.49%,showing significantly higher effect than the two single chemicals;protective and therapeutic effects by pot test against Pseudoperonispora cubensis,in 7d,were 51.36%and 58.49%,as for Fusarium oxysporum the effects,in 20d,were 56.36%and 47.54%.Significance test of difference results indicated that there was no significant difference between the sample and contrast agents.5.Field efficacy trials of Botrytis cirerea,Pseudoperonispora cubensis and Fusarium oxysporum results showed that,at the concentration of 225 mg/L,control effects of 4.5%propamidine-chitosan SL against Botrytis cirerea,7d after the forth spraying,were 58.47%and 64.21%on leaf and fruit respectively,which has no significant difference between 400 g/L Pyrimethanil SC 500mg/L;its control effects against Pseudoperonispora cubensis was 60.32%,7d after the third spraying;pouring root effects of 4.5%propamidine-chitosan SL 225 mg/L against Fusarium oxysporum was 52.36%7d after pouring for the second time.