Tinvestigation Of Several Diseases And Pests Of Walnut In Shaanxi Province And Field Control Research

Walnut(Juglans regia)is one of the four largest nuts in China.With the continuous expansion of walnut producing areas,walnut diseases and pests have been becoming increasingly serious.Investigation and identification of different types of walnut diseases and pests in different regions,and investigation of different field management levels and control effects will be beneficial to the understanding of walnut diseases and pests and to provide scientific basis for field management.In this study,the pathogens of common walnut diseases(walnut anthracnose,walnut blight and walnut bacterial black spot)were isolated and identified indoor.The indoor screening of fungicides were conducted by agar diffusion method,mycelial growth inhibition method and so on.Under different management levels,the control effects of different fungicides were compared.All of these would provide scientific basis for field control of walnut diseases and pests.The main results are listed as follows.1.Through indoor isolation and identification,the pathogens of walnut anthracnose,walnut branch blight,and walnut bacterial black rot were Colletotrichum gloeosporioides,Melanconium oblongum and Pantoea agglomerans,respectively;2.All of the eight test fungicides had a certain inhibiting effect on C.gloeosporioides,of which Tebuconazole showed the most significant inhibiting effect(EC50 1.0649 mg/L);3.Among the 13 fungicides,Zhongshengmycin,streptomycin sulfate,copper acetate,fluazinam,copper succinate,kasugamycin,dichloroanthraquinone had some inhibiting effects on P.agglomerans;4.The field investigation showed that the damage rate of walnut fruits and leaves planted under the fine management mode was lower than that planted under the extensive management mode.The diseases and pests of tall pole crops interplanted under walnut forest were more serious;5.In the experimental station,the different planting densities of walnut forest had no significant effects on the occurrence of canker and scale insects;6.The investigation of the healing condition of walnut branch trimming showed that the trimming,diameter of which was more than 3 cm,should be brushed by the cutting oil,benefiting both the heal of the trimming and reducing the infection of diseases.The results of this study can provide guidance and reference for the prevention practice of walnut diseases and pests,which is significant for promoting the healthy development of walnut industry in Shaanxi Province.