Investigation And Integrated Control Measures Of Diseases And Pests Of Cycad In The Cycad Garden Of Qingxiushan Scenic Spot

Cycadales are called "living fossils" in the plant kingdom.The Cycad Garden in Nanning Qingxiushan Scenic Spot was built in 1998 and is known as a cycad garden with "the best landscape,the oldest tree,the largest diameter at breast height,and the tallest plant" in our country.This thesis is the first investigation and integrated control measures of diseases and pests of cycad in Qingxiunshan Cycas Garden.The main research results are as follows:1.There were 8 kinds of pests and diseases of cycads in the Cycad Garden of Qingxiushan Scenic Spot: Chilades pandava,Aulacaspis yasumatsui,anthracnose(Colletotrichum sp.),leaf blight(Phomopsis cycadis),leaf spot(Ascochyta cycadia),green algae disease(Chlorococcum sp.),root-stem rot(Fusarium solani)and abnormal Cone.Green algae disease and and abnormal cone were the firstly found on cycads in this survey,and the green algae disease had already occurred in the garden seriously,which should be paid enough attention.Root-stem rot(Fusarium solani)was low incidence but the fatality rate was high,which is a major hidden danger for ex-situ conservation of cycads.Cycas elongata has the highest incidence rate and incidence index,and should be mainly paid attention to this disease。2.Combining the investigation of diseases and pests and management of cycads,the relationship between the occurrence of diseases and pests,cultivation,maintenance and seedling breeding were analyzed,and it was found that there were still problems in the garden management such as weak scientific research,insufficient labor,and lack of maintenance standards and procedures.3.According to the species of pests and the actual conservation situation of the Cycads Garden,the comprehensive management countermeasures are put forward.which should focus on plant quarantine and setting up isolation and observation areas for introduced seedlings,adhere to garden technology control as the basis for implementation of fine garden management,rational use of chemical agents and flexible implementation of pest control operations,green ecology,protecting and using natural enemies for biological control,actively exploring and advancing research on physical control,developing new science popularization projects,combining integrated prevention and control work to science popularization;carrying out landscape enhancement and transformation,rational use of non-cycads mixed and other perspectives,more entry points and multiple measures to solve the problem of pests and diseases of cycads in the Cycad Garden.It was formulated a schedule for daily maintenance of cycads and a schedule for pest control.4.The current dangerous species of cycad pests and diseases which should be quarantined from other countries,the improvement of scientific research level of the Cycad Garden,the treatment of old death plants in the Garden,and the advantages of the institutionalized management were also discussed in this thesis.In summary,this study carried out a survey of cycad plant diseases and insect pests in the Qingxiushan Cycad Garden,and put forward integrated control measures and formulated the garden maintenance regulations.It is of great significance to further improve the ex-situ conservation of cycad in Qingxiushan Cycad Garden,and it also provides a reference for the ex-situ conservation and management of rare plant in Guangxi or the whole country.