Studies On The Preparation And Application Of Modified Chitson For The Prevention And Control Of Diseases And Insect Pests Of Fruits And Vegetables

At present,the pest and germs control of crops still rely on frequent spraying of pesticides,resulting in the increase in farmer production costs,serious pesticide residues,environmental pollution.and hidden dangers for the national health.it has been urgent solved problem in twenty-first century.Therefore,it is imperative to explore the use of new pest and germs control materials to replace pesticides.In this paper,for the formation of composite membrane with long-term inhibition of plant pathogens,chitosan with good film-forming property and slow-release properties,combined with nano-zinc oxide and salicylic acid which also have good antibacterial properties.Experiments show that grafted salicylic acid and doped nano-zinc oxide can greatly improved the antibacterial properties and functional time of chitosan.The release time of salicylic acid of the composites membrane reached 85 h,release rate reached 53.73%.The antimicrobial experiments showed that the composites membrane were highly sensitive to banana fusarium wilt,bacterial wilt and anthracnose(the diameter of the inhibition zone was bigger than 10mm).Subsequently,hydrophilic chitosan derivative-tetraethylene pentamine chitosan(TECS)was obtained by chitosan grafting with tetraethylene.Then,TECS admixed with graphene by electrostatic interaction,which can effectively carry natural ginger essential oil.so we obtained a biodegradable deworming composite membrane by with insecticide and insecticidal activity.The composite film has good release performance of ginger essential oil,while the release time reached 168 hours,the release rate reached 40%.Moreover,the composite membrane can significantly reduce the oviposition rate of orange flies,the maximum repellent rate reached 74.2%.Finally,,chitosan with good film-forming properties and drug-loaded sustained-release properties,combined with harmless antibacterial materials-nano-zinc oxide and salicylic acid,and natural insect repellent material-ginger essential oil,respectively.we obtained harmless composite membrane with resistance to disease and pest.The composite membrane sprayed on the surface of fruits and vegetables to form a protective film,is expected to replace the traditional pesticides,and some alternative to the traditional melon bagging technology to solve the increasing current pests and diseases,pesticide abuse,and pesticide residues.The harm of pests and diseases in agriculture is increasing,the resistance of pests and diseases is also increasing,the dosage of pesticides is increasing and the number of spraying is increasing.Not only is the increase of farmers' production cost,but also causes serious pesticide residues and environmental problems.It is imperative to study the environmental protection materials.The preparation of controlled release polymer materials,through the composite pest control of natural non-toxic biodegradable substances,can achieve long-term inhibition of plant diseases and insect repellent effect,help solve the current pests and diseases,pesticide use,The number of use and pesticide residues and other serious problems.The material sprayed to the fruit,the surface of the vegetable can form a prote ctive film to achieve pest control effect,and the use of more simple and convenient,which can partially replace the traditional fruit bagging technology,which reduces the farmers production and labor costs,In line with the vital interests of farmers,a nd is conducive to solving the traditional bagging brought about by environmental pollution and other issues.