How to identify and control anthracnose in clivia? A detailed guide to topdressing methods for edible fungi

I. Symptom characteristics

Clivia anthracnose is a common fungal disease in the process of clivia cultivation and management, and both mature and young plants can be affected. The disease mainly infects the leaves, especially the leaf margins of the middle and lower leaves of the plant, which are more susceptible. In the early stage of the disease, brown spots appear on the leaf surface, and later gradually expand into round or oval shapes, slightly sunken, with concentric ring patterns. In the later stage, the lesions gradually dry up, and many small black dots are scattered on them. When the disease is severe, the whole plant is affected, causing the leaves to turn black and wither.

II. Occurrence pattern

The pathogen overwinters as mycelium in host residues or soil. In early April of the following year, the old leaves begin to develop the disease. When the temperature reaches 22-28°C in May to June, it develops rapidly, and the disease is severe in the rainy season with high temperature and high humidity. The pathogen spores spread through air currents, wind and rain, watering, and so on, and mostly invade through wounds. The disease is severe when the plant is given excessive nitrogen fertilizer, lacks phosphorus and potassium fertilizer, and is in poor ventilation and light conditions.

III. Control methods

1. Improve environmental conditions, pay attention to ventilation and light, appropriately increase the application of phosphorus and potassium fertilizer in nutrient management, control the amount of nitrogen fertilizer applied, and improve the disease resistance of the plant.

2. For affected plants, promptly prune off the diseased leaves and burn or bury them deeply.

3. Improve the watering method, and water should be poured from the edge of the flower pot; the potting soil should also drain well, and the moisture of the potting soil should be reduced as much as possible.

4. In the early stage of the disease, spray 70% thiophanate-methyl wettable powder at 1000-1500 times dilution, or 60% anthracnose fumate wettable powder at 800-1000 times dilution, once every 7-10 days, for 3-5 consecutive times, which can play a therapeutic and preventive role.

(Ding Shimin, Department of Landscape Engineering, Weifang Vocational College)