Orchid Disease and its Control

Orchid is an ornamental plant of Orchidaceae. The common diseases are anthracnose and leaf spot.

1, orchid anthracnose: mainly harmful leaves, black-brown disease spots appear on the leaves at the beginning of the disease, and there is a faded green halo around. After enlargement, the lesion is oval or strip-shaped. The edge is dark brown, the interior is yellow brown, and the disease spot is slightly raised. In the later stage, black particles appeared on the disease spot, and the black particles extruded pink colloids under wet conditions, that is, the conidia disk and conidia pile of pathogens. Anthrax occurred for a long time, especially from July to August.

Prevention and treatment: ① pay attention to ventilation and light transmission. ② fertilized reasonably, improved disease resistance, controlled the application of nitrogen fertilizer during the growing period, and applied more phosphorus and potassium fertilizer appropriately. At the initial stage of ③, 50% carbendazim or 70% topiramine wettable powder was sprayed 500-800 times.

2. Orchid leaf spot: it is a fungal disease harmful to leaves, which can occur in the whole growing period. Leaf spot disease is easy to occur in high temperature and humidity, shell insects and poor ventilation.

The initial stage of leaf spot is brown spot, after enlargement, the spot is long oval to striped, the edge is reddish brown, and the inside is grayish brown. In the later stage, black grains are scattered on the plaque.

Control: ① improves ventilation conditions and eliminates pests. At the initial stage of the onset of ②, 50% methamphetamine 1000-fold solution or 65% Dysen zinc 800-fold solution were sprayed for prevention and treatment.