June is the period when apple fruits are enlarging, new shoots are growing, and flower buds are differentiating. It is also a crucial time for disease and pest prevention and control. Proper orchard management during this stage plays an extremely important role in achieving high apple yields. Let's discuss the key points for preventing and treating apple diseases and pests in June.
Key Points for Preventing and Treating Apple Diseases and Pests in June
1. Rot Disease
Symptoms: Rot disease on apples is characterized by the appearance of "oozing" on the trunk. Brown bulges may appear, and when pressed, yellowish liquid may flow out. There are small black dots around the diseased area, and after rainfall, light yellowish coil-like substances may be observed.
Prevention and Treatment: In late June, the peak period of rot disease infection each year, scraping the bark of the trunk and applying 300 times dilution of 25% propiconazole or 300-400 times dilution of ferrous sulfate can eradicate the pathogens.
2. Spot Leaf Drop Disease
Symptoms: Initially, brown circular spots appear on the leaves, which gradually expand into reddish-brown or purple-brown areas. Concentric rings or dark spots may be present in the center of the spots, and multiple spots may merge into patches and eventually rupture. After heavy rainfall, black mold-like substances may grow on the diseased parts.
Prevention and Treatment: Before rainfall, spraying 80% thiophanate-methyl, mancozeb, or polyoxin can eliminate the spread of pathogens carried by rainwater and prevent widespread infection.
3. Anthracnose Disease
Symptoms: Both fruit and trunk can be infected. Fruits develop brown circular spots that sink and rot. When cut open, the affected area appears funnel-shaped and bitter-tasting. After rainfall, concentric rings and red mucilage may appear on the diseased part. Severe cases can cause fruit drop. Infected trunks exhibit cracked bark and black granules on the surface of the lesions, with branches becoming dry.
Prevention and Treatment: Before bagging apples, spray 2000 times dilution of iminoctadine 2000 times liquid. After bagging, spray 200 times dilution of Bordeaux mixture. Alternating with 800 times dilution of 50% thiram powder every 15-20 days. Prune excess branches, improve ventilation, light transmission, and orchard humidity, and implement flood prevention measures.
4. Aphids
Symptoms: Aphids gather on new shoots, tender buds, and leaves, causing leaf curling and roughness. Growth of new shoots is affected, hindering canopy expansion. Severe infestations affect young fruits, causing many reddish spots on the surface.
Prevention and Treatment: 7-10 days after bagging apples, spray Bordeaux mixture in appropriate quantities. During aphid outbreaks, use 2000 times dilution of 15% acetamiprid or 4000 times dilution of 10% imidacloprid wettable powder. When spraying, pay attention to the undersides of leaves.
5. Spider Mites
Symptoms: Primarily affect leaves, causing initial loss of green color, followed by whitening or browning resembling burn marks, severely affecting photosynthesis. Also affect flower bud differentiation and fruit development, causing loss of luster, roughness, color inconsistency, reduced fruit size, and decreased commercial yield.
Prevention and Treatment: When the number of spider mites on each leaf exceeds 5, spray 2000 times dilution of 1.8% abamectin or 2000 times dilution of 15% fenpropathrin emulsion. Spray every 7-10 days. In case of russet mite outbreaks, add fluorine pyrimidine for better control.
6. Peach Fruit Borer
Symptoms: Larvae infest young fruits, oozing tear-like liquid from the fruit entrance hole, which dries into white wax-like substances. Affected young fruits develop into uneven deformed fruits, with large insect holes and sometimes attached insect feces.
Prevention and Treatment: When peach fruit borers emerge from the soil in June, spray 800-1000 times dilution of 48% trichlorfon on the ground around the tree. Then, clean up dead larvae. When their numbers increase in late June, timely spray 1500-2000 times dilution of 30% phosmet emulsion or 1000-1500 times dilution of chlorpyrifos.
Above are the key points for preventing and treating apple diseases and pests in June. June is the period of apple fruiting, and various diseases and pests begin to infect and cause harm during this time. The principle of disease and pest control is "prevention and treatment," aiming to minimize the use of pesticides.
