Screening Of Biological Pesticide For Greenhouse Tomato Diseases And Insect Pests In Yangling

The suitable environment in the greenhouse promotes the growth of tomato and also causes the occurrence of a large number of pathogens and pests.In addition,the way of continuous cultivation is resulting in increasingly serious damage to tomato pests and diseases.Today's consumers have generally improved the quality and safety requirements of fresh food products.Avoiding pesticide residue contamination and improving the safety and quality of fruit have become an important part of quality production.Therefore,under the premise of stable production and increased production,the development and research of alternative technologies and products for chemical pesticides has become an important way to solve environmental pollution and food safety problems.In this study,we investigated the major pests and diseases of greenhouse tomato during the whole breeding period,selected several commercially available bio-sourced pesticides as test agents,executed indoor toxicity trial,safety assessment and field efficacy measurement on the major pests and diseases of greenhouse tomato and developed a prevention and control scheme using bio-sourced pesticides of greenhouse tomato.The results of the study are as follows:1.The investigation for the major pests and diseases of greenhouse tomato in Yangling indicated:The main diseases include root diseases stem root rot,root rot,and blight,as well as leaf diseases early blight,late blight,gray mold,and leaf mold.Disease usually occurs after planting and continues until the end of production.Root diseases usually occur before the initial flowering period after planting.The conditions of high temperature and high humidity in the greenhouse from late September to early October are prone to early blight and occasionally leaf mold.During the rainy season in Yangling in October,the temperature dropped rapidly,and the condition of low temperature,high humidity and poor illumination would cause a rapid outbreak of late blight.From November to May,the most serious disease was tomato gray mold and tomato leaf mold.Failure to timely control the disease will result in serious reduction of production in the shed.In addition,after entering the fruit period,it is prone to symptoms of physiological diseases such as falling,falling fruit,and cracking fruit.After the planting in August and September,bemisia tabaci have occurred.From the end of March to April of the following year,the radish on the rape moved into the shed to damage the greenhouse tomato.2.The results of indoor toxicity trial indicated that:The virulence of 4 test biogenic agents for Botrytis cinerea,Alternaria solani Sorauer and Phytophthora infestans Bary,the virulence of 0.4%Osthole SL was the highest,and EC50 was 1.885g/ml,1.561g/ml,1.261g/ml,1.5%Matrine·Osthole AS,EC₅₀0 respectively:3.039 g/ml,5.526g/ml,4.560 g/ml;0.3%Matrine EC₅₀0 was lower than the first two drugs,and EC₅₀0 was 3.195 g/ml,8.036 g/ml,10.135 g/ml;0.5%BerberineAS was the worst,EC₅₀0 value was greater than 10 for the weak inhibition of bacteria.In the determination of indoor virulence of Bemisia tabaci,the efficacy of plant source medicament 0.3%MatrineAS was close to that of methylene salt,and LC₅₀was 11.559 g/ml;0.5%Veratrine SL was the worst virulence,LC₅₀0 was 29.699 g/ml,which did not have the value of further field prevention and control.3.Field experiments showed that:the tested biosource agents were safe for tomato growth,and had no adverse effects on their growth.In the field test of Botrytis cinerea:The7d control effect of 0.4%OstholeSL 200 times after the first times of drug was as high as61.44%.There was no difference in the 14d control efficacy after the last application between the 0.4%OstholeSL andthe chemical Methionine·Dimethicam.The 14d control effect after the last application of OstholeSL 200⁴00 times was 67%to 74%.The 14d control effect after the last application of 0.3%MatrineEC 200 times was 62.21%.The 14d control effect after the last application of 1.5%Matrine·Osthole AS 800¹200 times was 60%⁶9%.In the field test of Tomato Late Blight:The 7d control effect of 0.4%OstholeSL 200times after the first times of drug was as high as 60.05%,amlost same as chemical Fluvior.The 14d control effect after the last application of OstholeSL 200⁶00 times was60%⁷6%.The 14d control effect after the last application of 1.5%Matrine·Osthole AS 800times was 67.02%.There was no difference in the 14d control efficacy after the last application between the 1.5%Matrine·Osthole AS 1200 times and the chemical Fluvior.Two groups of field efficacy trials showed that the biosource agent efficacy was longer,the dosage form was more environmental friendly and no phytotoxicity.4.The experiment in yield of Plant immune-promoting protein showed that:It can effectively improve the growth of tomato plants that sprayed the Plant immune-promoting protein at the seedling stage,nutrition stage and flowering stage.There is a significant difference in plant height and stem diameter between the other treatments and the clear water control.In conclusion,combined with the results obtained by biological pesticides in other crops,the whole biological pesticide prevention and control scheme of greenhouse tomato was concluded.The preliminary application proved that the scheme could effectively prevent and control major diseases and insect pests of greenhouse tomatoes.It is worth further promoting.