Apple diseases—spotted defoliation: 80% mancozeb, acetonitrile, and iprodione can prevent and cure this disease.
Powdery mildew: often occurs in spring. Pyraclostrobin, pyrizostrobin sulfonate, cloconazole, and triadimefon can prevent and treat this disease.
Anthrax: Usually onset in May. Methylthio-tebuconazole, prochloraz, and bromiostrobin can prevent and treat this disease.
Two-spotted spider mite: Bordeaux mixture and organic fungicides can control this disease.
Apple diseases—spotted leaf disease
- Harm
Brown, nearly round spots will appear on the leaves in the early stages of the disease. As the disease progresses, the lesions gradually expand and become connected, and the edges become purple-brown. When wet, a dark green to black gray mold layer develops. The onset period is generally between June and September. - Prevention and treatment methods
The key lies in the protection of new shoots during the germination period. You can choose 80% mancozeb, acetonitrile, iprodione, etc. If the disease has already occurred, hexaconazole, azoxystrobin, etc. can be administered. Tebuconazole can be used for control after bagging.
Apple diseases – powdery mildew
- Harm
It is easy to damage young leaves, new leaves, flowers, young fruits, etc. Shown as dead shoots and new shoots curling. There is a white powder layer on the leaves and fruits, and the flowers and fruits are deformed. Warm and dry springs and rainy and cool summers are conducive to the occurrence of the disease. - Prevention and treatment methods
The flower dew is red before budding. Before and after the flowers fall and before bagging are the key prevention and control periods. Pyraclostrobin, pyrizostrobin sulfonate, cloconazole, and triadimefon can prevent and treat powdery mildew.
Anthracnose
- Harm
It mainly damages leaves and fruits. When the leaves are infected, black necrotic lesions form on the leaf surface in the early stage, and the edges of the lesions and healthy parts are blurred. Then the lesions begin to spread and connect into sheets, causing the leaves to scorch. Fruit disease occurs, with ring-shaped lesions. Red mucus precipitates when wet. Generally, the onset of symptoms occurs after May, and the condition will develop rapidly in case of continuous rainfall. - Prevention and treatment methods
Methylthio-tebuconazole, prochloraz, bromystrobin, etc. can prevent and treat this disease. Pay attention to garden cleaning in the early stage and prevention and control during the initial infection period. Otherwise, the disease will be difficult to control in the rainy season.
Two-spotted spider mite
- Harm
There is a lot of rain, high temperatures and high humidity in summer. Diseases such as brown spot, anthracnose leaf blight, ring scab, anthracnose, and scab are prone to occur. - Prevention and treatment methods
Bordeaux mixture sprays alternate with organic fungicides. Bordeaux mixture is resistant to rainwater erosion and its efficacy lasts for about 15 days. Spray 1:2:200 times Bordeaux liquid before rain, and spray systemic organic fungicide after rain. The agent can be 43% tebuconazole 4000 times and 20% difenoconazole 2000 times. 70% thiophanate methyl 800 plus 80% mancozeb 8000 times. When spraying, you can add foliar fertilizer such as 0.3% potassium dihydrogen phosphate. Increase tree nutrition and improve disease resistance.
