How to Use Chemical Fertilizers to Prevent And Control Crop Diseases And Insect Pests?

Nitrogen fertilizer

Nitrogen fertilizers, such as ammonium bicarbonate and ammonia water, have strong volatility and have certain stimulating, corrosive and fumigation effects on pests, especially for small spiders, aphids, thrips and other small insects with weak endurance.
Application method: Spray evenly with 1% ammonium hydrogencarbonate or 0.5% ammonia aqueous solution, spray once every 5 to 7 days, and spray 2 to 3 times.
Urea has the function of destroying the chitin of insects. It is prepared by mixing urea, washing powder and water in a ratio of 4:1:400. It has controlling effects on aphid, cabbage caterpillar and red spider that is harmful to cotton, vegetables and flowers.

Phosphate fertilizer

Superphosphate: The oxalic acid secreted by the glandular hairs on the cotton tender head has an attracting effect on the cotton bollworm moth, and the oxalic acid can be converted into calcium oxalate by using 1% to 2% calcium phosphate leaching solution for foliar spray fertilizer during the adult stage of cotton bollworm, so that the lure to the cotton bollworm is lost. This can reduce the amount of eggs in cotton fields by 33.3 to 73.4%, with an average of 55%. The duration of each spraying of phosphorus is generally 2 to 3 days.
Tomato umbilical rot is a physiological disease caused by calcium deficiency in plants. It is sprayed once every half month from the initial flowering stage of tomato with 1% superphosphate leaching solution, and the prevention effect after 2 to 3 times spraying is obvious.