Diseases and Pests of Hibiscus and Their Control

Hibiscus disease control

powdery mildew

Powdery mildew mainly harms the leaves of hibiscus. At first, many small spots will appear on the front of the leaves, which will gradually expand into large white powdery spots. In autumn, small black-brown spots will appear on the white powder. In severe cases, it can cause the leaves to turn yellow and wither, weakening the entire plant. Diseased plants should be burned promptly when found. In the early stage of the disease, they should be treated by spraying drugs, 2000 times diluted 25% oxycarboxin, or 1500 times diluted 70% thiophanate-methyl wettable powder.

Hibiscus Pest Control

Tussopus horned moth

Newly hatched larvae will gather on the back of the leaves to feed on the mesophyll, leaving only the upper epidermis. After the third instar, they will disperse to feed and hibernate under the bark. Mature larvae will spin cocoons and become pupae on the back of the leaves. For prevention and control, you can scrape off the larvae that hibernate under the bark in winter. In early or mid-June, you need to spray pesticides. You can use 2500 times diluted 20% trichlorfon emulsifiable concentrate or 1000 times diluted 90% dichlorvos.

Green leafhopper

It mainly harms the leaves, causing white spots to appear. In severe cases, it can cause the entire leaf to turn white and fall off, seriously affecting the growth of the plant. Weeds should be removed around the plants to destroy the places where pests and diseases overwinter. During the peak period of the first outbreak, spray 1500 times diluted 50% carbofuran, 50% chlorpyrifos, pyrethroid insecticides, or 1500 times diluted 50% malathion.

Tetranychus cinnabarinus

In the early stage of the disease, the affected leaves appear as small yellow-white spots, which slowly spread to the entire leaf, causing it to turn yellow, curl, and fall off.

Spray 1500 times diluted 40% oxydemeton-methyl on the back of the leaves for prevention and control.

Other pests

Other insects that harm hibiscus include aphids, red spiders, scale insects, etc., which can be controlled by spraying 100 times diluted 50% DDT, 100 times diluted 50% dicofol, or 2500 times diluted 20% cypermethrin.

Pest and disease control is a big lesson we need to learn. I hope the methods introduced above can help everyone. I hope everyone can grow healthy and beautiful hibiscus.