Screening Of Chemical Control Agents For Botrytis Cinerea In Greenhouse In Guanzhong Region

With the development of modern agriculture,greenhouse cultivation has become the main mode of vegetable cultivation,because the greenhouse production environment is relatively closed,greenhouse vegetable diseases have the characteristics of rapid occurrence,large spread and expansion area,etc.This paper selects Botrytis cinerea as the research object.Botrytis cinerea is an important disease in the growth period of tomato,the pathogen has the characteristics of rapid reproduction and easy spread of conidia,pathogens are highly resistant to drug resistance,seriously affecting tomato yield and economic benefits.This test uses Botrytis cinerea as the test bacteria,the sensitivity of Botrytis cinerea to nine test agents was determined by mycelial growth rate method,and through field trials in different regions,screen out suitable local chemicals,provide pharmaceutical choices for the control of Botrytis cinerea,and provide scientific support for production practice.The results of the study are as follows:1.The results of indoor virulence test showed that nine different types of test agents had different virulence performance against Botrytis cinerea.Among them,22.5%oxystrobin water-dispersible granules have the highest virulence level against Botrytis cinerea,its EC₅₀0 is 1.34?g·mL^-1.The EC₅₀0 value of 75%chlorothalonil WP is30.59?g·mL^-1.The EC₅₀0 value of 50%isourea suspension is 7.55?g·mL^-1.The EC₅₀0 value of400g/liter of pyrimethanil suspension was 8.20?g·mL^-1.50%boscalid water dispersible granules have an EC₅₀0 value of 4.50?g·mL^-1.The EC₅₀0 value of the 50%fluazinam water-dispersible granules is 3.55?g·mL^-1.The 50%Pythium WP has an EC₅₀0 value of 7.57?g·mL^-1.The EC₅₀0 value of the 50 g/L hexaconazole suspension was 1.65?g·mL^-1.The EC₅₀0 value of the 25%pyridine oxazole water emulsion is 3.44?g·mL^-1.2.Field efficacy test results show:Yangling Experimental Field:50%boscalil water dispersible granules 40g/mu treatment after 10 days of last application,the leaf control effect was 84.09%,and the fruit control effect was 80.54%.The control effect was significantly different from that of the control agent 42.4%azole ether·fluoroamide suspension 25 ml/mu.Baoji experimental field:25%pyridine oxazide water emulsion 80ml/mu treatment in the 10 days after the last drug,the leaf control effect was 81.08%,the fruit control effect was 79.96%,the control effect was significantly different from that of the controlagent26%pyrimidine-pyridylbacteriawater-dispersiblegranules50ml/mu.Xianyang experimental field:22.5%oxystroxane suspension agent 31g/mu treatment in the 10 days after the last drug,the leaf control effect was 83.23%,the fruit control effect was 79.87%,the control effect is significantly different from that of the control agent 65%methylsulfate-methylcarbamate wettable powder 60g/mu treatment.The test agent has no adverse effect on tomato growth and were safe to use.3.In summary,the 22.5%oxystroxane suspension,50%boscalid water dispersible granules,and 25%pyridine oxazide water emulsion in the test agent have better control against Botrytis cinerea in Guanzhong area.The effect is significantly higher than the local conventional pharmacy.When applied in the field,the above agents can be used alternately to reduce the single use frequency of the medicament,avoid the generation of resistant strains of Botrytis cinerea in the field,and improve the control effect.The chemical control can be combined with other control measures to delay the resistance of pathogens of Botrytis cinerea and improve the control effect.