Pest control methods for cold orchid

Sheath Rust

Symptoms

Raised pustules usually appear on the upper and lower surfaces of leaves and less often on the stems, containing powdery spores that are yellow, orange, rusty, or even purple-black. Rust is not fatal and the leaves will not die, but it will weaken the plant.

Prevention and treatment methods

In addition to cutting off the diseased leaves, you can spray with 500-600 times diluted 65% Zineb powder or copper-containing fungicide.

Sclerotium rolfsii

Symptoms

It often occurs in rainy season. When the disease first occurs, the leaf base is covered with white mycelium, causing the rhizomes to rot.

Prevention and treatment methods

Remove the infected soil and sprinkle with pentachloronitrobenzene powder or lime. Radical treatment method: pay attention to ventilation and light transmission, and ensure good drainage of the potting soil. Severely diseased plants should be burned.

Scale insects

Symptoms

Commonly known as "orchid lice". Reproduction is fastest in hot, humid conditions with poor air circulation.

Prevention and treatment methods

During the incubation period, 1% omethoate or 1500 times 50% malathion spray can be used. If there are not many pots, they can also be removed manually.

Nematodes

Symptoms

It parasitizes inside the leaves, causing yellow and brown spots to appear on the leaves of the orchid and causing necrosis.

Prevention and treatment methods

It can eliminate the source of disease, burn the entire diseased plant, treat planting materials, and prevent poisoning of humans and animals.