Occurrence and Control of Common Flower Anthracnose and Methods for Preserving Edible Fungi

(1) Camellia Anthracnose

1. Symptoms: It mainly damages leaves and tender shoots. The pathogen mostly invades from leaf tips and leaf margins, forming round or irregular lesions. Dark brown, with raised edges, the lesions vary in size. In the later stage, small black dots grow on the lesions, arranged in rings or scattered. When humidity is high, pink sticky masses ooze out. Diseased leaves dry up and fall off easily. Lesions on new shoots are elongated, slightly sunken, light brown, with distinct edges; in severe cases the shoot tips die.

2. Disease pattern: The pathogen overwinters as mycelium or acervuli on diseased plants and diseased debris, and spreads through wind and rain. It mostly invades through wounds and weakened parts. Weak plant growth, poor drainage, high temperature and high humidity favor the occurrence of the disease.

3. Control methods

Remove dead branches and fallen leaves, cut off diseased branches and destroy them. Apply more organic fertilizer, phosphorus and potassium fertilizer and ferrous sulfate to enhance disease resistance. Spray after new shoots emerge. Use "50% carbendazim 800-fold solution, 70% thiophanate-methyl 1000-fold solution, 75% chlorothalonil 800-fold solution or 80% anthracnose fumate 800-fold solution, once every 10-15 days, spraying 4-5 times in succession.

(2) Jasmine Anthracnose

1. Symptoms: It mainly damages leaves, and sometimes also damages tender shoots. The leaves first show small chlorotic spots, which later expand into light brown, round or nearly round lesions, 2-10 mm in diameter. The center of the lesion is grayish white, the edge is brown and slightly raised. In the later stage, sparse small black dots are arranged in rings on the lesions.

2. Disease pattern: The pathogen overwinters as mycelium and conidia on diseased leaves. It spreads through wind and rain and invades through wounds. Generally, the disease is more severe during summer and autumn.

3. Control methods: Same as camellia anthracnose

(3) Aglaia Anthracnose

1. Symptoms: It mainly damages leaves, and sometimes can also damage petioles and tender shoots. Leaf lesions are mostly at the leaf tip and leaf margin. Semicircular or irregular, with wavy shrinkage; the lesions are initially yellowish brown, later turning grayish white, with brown edges, slightly raised. The lesions can expand to the entire leaf surface. Small black dots are scattered on the diseased parts. When petioles and tender shoots are affected, small branches and branch trunks die, causing early leaf fall.

2. Disease pattern: The pathogen mainly overwinters as mycelium and conidia on fallen leaves and diseased dead shoots, spreads through wind and rain, and invades through wounds. This disease has the characteristic of latent infection. The disease is severe when plant growth is weak. Seedlings during transport or just after transplanting are prone to the disease.

3. Control methods

Promptly remove diseased fallen leaves and diseased branches and destroy them in a centralized manner. Strengthen the management of seedlings during transport and transplanting. For seedlings that need to be transported, spray once before lifting the seedlings, such as 50% carbendazim 1000-fold solution or other systemic fungicides. Spray promptly in the early stage of the disease; for chemicals, refer to camellia anthracnose.

(4) Rohdea Anthracnose

1. Symptoms: The disease mostly occurs at leaf tips or leaf margins, starting as small water-soaked yellow spots, gradually expanding into round, oval, and even irregular large lesions, with the center grayish white or grayish brown, with indistinct cloud-like markings, and the edge dark brown. In the later stage, many small black dots form on the lesions, arranged in concentric rings. Finally the lesions dry up. When the disease is severe, it can spread to the petioles.

2. Pathogen and disease conditions: This disease is a fungal disease caused by infection with Colletotrichum rohdeae. It is commonly seen on potted plants in greenhouses from August to November each year, and the damage is relatively severe. Old leaves are more affected. Poor indoor ventilation or damage by scale insects makes the disease more likely to occur.

3. Control methods

(1) Strengthen cultivation management: Indoor potted Rohdea should be placed in a place with air circulation and sufficient sunlight. Do not apply too much nitrogen fertilizer; appropriately apply more phosphorus, potassium fertilizer and farmyard manure. Promptly remove and thoroughly destroy diseased leaves as soon as they are found.

(2) Chemical control: Before the disease occurs, spray 1% Bordeaux mixture. After the disease occurs, spray 75% chlorothalonil 800-fold solution, or 65% zineb 600-800-fold solution.

(5) Sago Palm Anthracnose

1. Symptoms: Sago palm anthracnose causes leaflets to die in segments or entirely. Black small dots form on the diseased parts. When moist, pink gelatinous material oozes from the dots.

2. Pathogen and disease conditions: The pathogen is Colletotrichum sp., Deuteromycotina, Coelomycetes, Melanconiales. The disease pattern is that the pathogen overwinters on diseased parts of the plant, and the disease is likely to occur in hot and rainy seasons. After sago palms suffer frost damage, the disease is also likely to occur.

(6) Cactus Anthracnose

Symptoms: Lesions on stem joints or stem bodies are round or nearly round, 4-8 mm in diameter, mostly occurring on the edges of ridges and angles, light brown to grayish white, with small black dots growing on them, arranged in concentric rings, and when moist, orange-red sticky spore masses ooze out. There is often a chlorotic halo around the lesions. As the disease develops, the whole area becomes light brown and rots.

(7) Clivia Anthracnose

1. Symptoms: Initially, small light brown spots appear on the leaves. As the disease develops, the lesions gradually expand into round or oval shapes (if the lesions occur at the leaf margin, they are semicircular). The diseased parts have concentric rings. In the later stage, many small black dots form, and under moist conditions pink sticky material oozes out.

2. Pathogen and disease conditions: This disease is caused by infection with a species of Colletotrichum (fungus). During cultivation, the disease occurs more when too much nitrogen fertilizer is applied and phosphorus and potassium fertilizer are relatively lacking. The disease is severe under high temperature and rainy, humid climates. If potted flowers are placed too densely or watered too much, with poor ventilation and high humidity, the disease is likely to occur.

3. Control methods

(1) Strengthen cultivation management: Do not apply only nitrogen fertilizer; appropriately apply more phosphorus fertilizer and potassium fertilizer to enhance the plant's disease resistance. Do not place indoor flower pots too densely, and maintain good ventilation conditions. Water should be poured in from the edge of the pot. Cut off diseased leaves or diseased parts of lesions. And promptly burn or bury them deeply to reduce sources of infection.

(2) Chemical control: During the disease period, spray 50% carbendazim 800-fold solution, or 70% thiophanate-methyl 1000-fold solution, or spray once 70% anthracnose fumate 500-fold solution.