The anaerobic fermentation of biogas fermentation raw materials through biogas digesters not only contains extremely abundant nutrient elements and microbial metabolites, but also contains hormones and antibiotics that increase the stress resistance of plants. Therefore, biogas slurry can not only be used to control plant diseases and insect pests, but also It can also improve plant stress resistance. ? Use biogas slurry to prevent and control different diseases, and produce agricultural products without pesticide residues, which will not pollute the surrounding environment during the production process. The dosage and the medicine used are also different and need to be treated differently. Here are some examples of the use of biogas slurry to prevent fruit tree aphids, red spider and wheat head blight, watermelon wilt disease, etc., for the reference of farmers' friends. 1. Control of locusts: When locusts appear in fruit trees and vegetables, biogas slurry can be used for prevention and control. The specific method is: using biogas slurry 14 kilograms, 10% detergent solution 0.5 kilograms, formulated as biogas compound insect repellent, spraying with a sprayer. Spray time is best chosen on a sunny morning. Spray 35 kg per acre and spray the next day. Production practice shows that using biogas slurry with good gas production to control fruit trees and vegetable aphids, spray once, the control rate is about 70%, spraying twice can reach more than 96%. 2, control fruit tree spider mites: In the apple, citrus and other fruit trees during the growth period, with biogas slurry or add a small amount of pesticide spray fruit trees can prevent fruit trees red, yellow spider and other pests and diseases. The higher the concentration of biogas slurry, the better the insecticidal effect. Adding imidacloprid or extermination and other pesticides when the fruit trees are sprayed with biogas slurry, the effect of killing eggs and killing eggs is very significant, and the potency of the drugs lasts for more than 30 days. 3, biogas slurry control of wheat scab: Fusarium head blight is one of the major diseases in wheat production, the incidence rate is high, the epidemic area is large. The biogas slurry in the normal fermentation biogas production digester has obvious control effect on wheat scab, its effect is equivalent to that of carbendazim used in production, and the use of biogas slurry liquid is the best effect, and the usage amount is usually Per acre spray 50 to 100 kg, spray once in the full flowering period, every 3 to 5 days before spraying again, the control rate can reach 80%. 4, biogas liquid control watermelon wilt disease: watermelon wilt disease is the enemy of watermelon production. In watermelon production, 20 times of biogas slurry can be soaked for 8 hours, and 10-20 times of biogas slurry can be sprayed on the growth stage for 3 to 4 times, which can basically control the occurrence of a large area of ​​blight. In watermelon enlargement period, combined with foliar spray of biogas slurry and topdressing with biogas residue, not only wilt disease is controlled, but also higher yield can be obtained, and the quality of watermelon is also improved. In addition, biogas slurry also has strong inhibition and extermination on cotton wilt disease and anthracnose, potato wilt disease, wheat root rot, rice leaf bacillus and sheath blight, corn leaf spot pathogen, and root rot of fruit trees. effect.