Control of orchid anthracnose and leaf spot

Orchids are ornamental plants. Common diseases include anthracnose and leaf spot.

1. Orchid anthracnose: mainly harmful to leaves, black-brown spots appear on leaves at the initial stage of disease, and there are faded green halos around. The enlarged spots were oval or elongated. The margin is dark brown, the inside is yellow brown, and the lesion is slightly raised. Black granules appeared in the late stage of disease spots, and under wet conditions, the black granules squeezed out pink colloid, namely conidia disk and conidia pile of pathogens. Anthrax occurs for a long time, especially in July and August.

Prevention: ① Pay attention to ventilation and light transmission. (2) Rational fertilization, improvement of disease resistance, control of nitrogen fertilizer application in growth period, appropriate application of phosphorus and potassium fertilizer. (3) spray 50% carbendazim or 70% thiophanate WP 500 - 800 times solution at the early stage of disease.

2, orchid leaf spot: is a fungal disease that damages leaves and can occur throughout the growth period. High temperature and humidity, scale insect damage, poor ventilation are prone to leaf spot disease.

The leaf spot was brown at the initial stage of disease, and after expansion, the disease spot was long oval to long strip spot shape, with reddish brown edge and gray brown inside. Black granular matter was scattered on the later disease spots.

Control: ① Improve ventilation conditions and eliminate pests. (2) spray 50% Tuijunte 1000 times solution or 65% Zineb 800 times solution at the early stage of disease.