Evaluation Of Chemical Pesticides Against Carya Cathayensis Canker Caused By Botryosphaeria Dothidea

Chinese hickory(Carya cathayensis)is an important tree for hickory production in China.The Tianmu mountain is the most distribution area of C.cathayensis,especially in Lin’An city,Zhejiang province.Now,the Chinese hickory becomes the most income of local farmers.Recently,a canker disease caused by Botryosphaeria dothidea occurred and became the most serious disease in Chinese hickory forest.C.cathayensis canker disease caused the death of thousands of trees and huge lost of income.In this research,we focused on the control strategy of C.cathayensis canker.The green pesticides were screened and investigated for controlling in forest.The results were listed as following:1.Antimicrobial activity using the growth rate method for the determination of quinoline copper and tebuconazole on Botryosphaeria of pathogen about pecan stem rot,and the actual control effect test.In vitro antibacterial activity of laboratory screening results: tebuconazole EC50 value: 1.41 mg/L,quinoline copper EC50 value is 3.93 mg/L.2.9 kinds of pesticides,including 30% difenoconazole·propiconazole EC,32.5% difenoconazole·azoxystrobin SC,40% myclobutanil WP,50% copper 8-hydroxyquinolinate WP,36% copper 8-hydroxyquinolinate·tebuconazole SE,1.6% benziothiazolinone EC,30% difenoconazole SE,25% Difenoconazole WG and 75% Trifloxystrobin Tebuconazole WG,were used to investigate their control efficiency against Chinese hickory stem canker in the field.From 2016 to 2017,the ratios of both canker recovery and new canker occurrence decreased significantly after application of these 9 kinds of pesticides.3.The pesticides 30% difenoconazole·propiconazole EC and 50% copper 8-hydroxyquinolinate WP were selected to assess the synergistic control effect after smashing the canker treatment.In 2016,comparing to the control,the ratio of canker recovery of 30% difenoconazole·propiconazole EC and 50% copper 8-hydroxyquinolinate WP decreased by 57.52% and 61.14%,respectively,as the ratio of new canker occurrence decreased by 36.19% and 34.75%,respectively.In 2017,there were no more canker recovery and new canker.In summary,the nine tested pesticides showed significant control effect on C.cathayensis canker disease.The smashing the canker treatment could lead to the synergistic control effect.In the future,the results in this research could contribute to the efficient control of C.cathayensis canker disease.