1. Control of gray mold

In April and May , gray mold still occurs in greenhouse-grown eggplant and melons, mainly affecting tomatoes, eggplants, strawberries, and zucchini. Continue to ensure proper ventilation by opening the greenhouse to reduce humidity, and remove diseased leaves and fruits. Use fungicides such as anti-drop agents and cypermethrin. After applying 2,4-D for 10 days, remove petals and stigmas. Use "Lide" fumigant to seal the greenhouse, and spray with integrated pest management products such as iprodione, procymidone, and chlorpyrifos to control gray mold damage.

2. Prevention and control of late-stage disease

April and May are ideal months for late blight in tomatoes. This disease can affect tomato leaves, branches, and fruits, causing leaf, stem, and fruit rot. The main difference between late blight and gray mold is that late blight causes water-soaked, soft rot spots on the affected areas, producing a thin, grayish-white mold. Gray mold, on the other hand, causes fruits to harden and develop a large amount of grayish-brown mold. Control measures for late blight include removing diseased leaves and fruits, pruning diseased branches, and spraying with fungicides such as acetamiprid, chlorothalonil, or cymoxanil, once every 5-7 days, for a total of 3 applications .

3. Prevention and control of viral diseases

Viral diseases can occur on vegetables such as solanaceous plants, melons, strawberries, and cruciferous vegetables. In tomatoes, they can cause various symptoms, including mosaic patterns, ferns, and stripes (on the stems). Viral diseases are mainly transmitted by aphids, and aphid control should be achieved by spraying with insecticides such as "Yiban Jing" (a pesticide). In the early stages of infection, spray with fungicides such as "Zhibingling" (a plant disease control agent), "Virus A" (an antiviral agent) , or "Junkeduke" (a fungicide ), applying every 5-7 days for 3-4 applications . For stripe-type viral diseases on tomatoes, prune diseased branches to encourage the growth of new shoots.

4. Control of downy mildew

Downy mildew primarily affects cucumbers, loofahs, and cruciferous vegetables in April and May . Recent feedback from farmers indicates that cucumber downy mildew is particularly severe, necessitating thorough investigation and control measures. The recommended pesticides are similar to those used for tomato late blight.

5. Snail and slug control

Snails and slugs are mollusks and harmful organisms. During April and May , with abundant rainfall, high humidity in the fields, and plentiful weeds, their damage intensifies. Omnivorous, they can damage cruciferous vegetables, solanaceous vegetables, melons, and spring corn, feeding on seedlings, leaves, and other tender tissues, creating notches and cavities, leading to gaps in the rows and gaps in the plant's growth. They also secrete slime that contaminates vegetables, affecting yield and quality. Integrated pest management should be implemented: thoroughly remove weeds from the field and surrounding areas before planting, till and expose the land to sunlight, apply lime to degrade snail habitats, and apply 6% Mistar GT or 5% Mestar G at 1 kg per acre in the evening for control. Do not use chlorpyrifos spray on vegetables, as this can easily cause phytotoxicity.

6. Control of spider mites and thrips

　　In spring , vegetables such as eggplant, tomato, cucumber, and loofah are often infested with spider mites and thrips. Spider mites mainly damage leaves and the undersides of leaves, sucking the plant's sap and leaving the undersides of leaves covered in webbing. Infested leaves turn yellow and fall off. Thrips can damage eggplant leaves and buds, sucking the leaf tissue and leaving only the epidermis. Infested buds cause young eggplants to become stiff, white, and lose their luster. Spider mites can be controlled by spraying with 73% chlorpyrifos, abamectin, or acetamiprid. Thrips can be controlled by spraying with 1000-1500 times diluted Dow's Spray ( can be harvested and marketed one day after spraying ), 2000 times diluted Ribamectin, or 2000-2500 times diluted acetamiprid .