Symptoms and preventive measures of orchid anthracnose

Orchids are also known as orchid flowers, the general term for orchids, orchids have a wide variety of species, there are now about 28,000 species have been accepted, orchid anthracnose harm a variety of orchid flowers, in the greenhouse when the disease is serious, sometimes causing the entire leaf to die.

1. symptoms

At the beginning, it was round or semicircular reddish brown spots, and gradually became dark brown later. The outer edges of the spots were mostly yellow. Severe when many lesions gathered together, wavy or striped black brown lesions. The middle part of the disease spots turned gray in the later stage, and many small black spots were born on them. The disease occurred most in the middle and upper parts of the leaves.

2. occurrence characteristics

In rainy season and greenhouse, the disease is serious, and the pathogen overwinters in the diseased leaf tissue. When the leaves are often sprinkled or the leaves are interlaced with each other, the disease spots are easy to expand and spread. Orchid resistance to this disease varies according to varieties, such as "Dafengsu" in Jianlan,"Dafugui" in Chunlan weak resistance, Jianlan "Tiegensuo" and "Pulan" strong resistance, and medium resistance of Cymbidium.

3. control methods

When watering, do not pour water on the leaves| Under the premise of ensuring air humidity, proper ventilation and light transmission, open the basin distance when placed to prevent infection. Cultivate disease-resistant varieties in areas with severe disease. Cut off the diseased leaves in time and burn them. Spray carbendazim 500 times solution every 7 days for 3 or 4 times. The effect is good.