Common diseases of Clerodendrum thomsoniae and their control methods

Common diseases of Clerodendrum thomsoniae: leaf spot

Symptoms

The Verbenaceae plant belongs to the Verbenaceae family and can develop leaf spot disease, which is caused by infection with Ascomycetes. At first there are just small brown spots. If not treated in time, large black spots will appear, and the leaves will turn yellow and die.

Prevention and treatment methods

Once the disease is discovered, you should immediately spray the leaves with 800 times diluted Benomyl, once every 7-8 days, for 2-3 times in a row, and the plant can be basically cured.

Common diseases of Clerodendrum thomsoniae: rust

Symptoms

Rust fungi generally only cause local infection. The affected parts may produce small blisters or blister-like, cup-shaped, or hair-like objects of different colors due to the accumulation of spores. Some may also cause tumors, rough bark, bushy branches, bent branches and other symptoms on the branches and trunks, or cause leaf fall, burnt tips, poor growth, etc. In severe cases, the spores accumulate in dense patches and the plants quickly die due to the evaporation of a large amount of water in the body.

Prevention and treatment methods

400 times diluted 70% mancozeb wettable powder and 700 times diluted 75% thiophanate-methyl wettable powder can effectively prevent and control rust disease of Ampelopsis thomsoniae.

Common diseases of Clerodendrum thomsoniae: mosaic disease

Symptoms

In the early stage of the disease, chlorotic angular spots appear on the leaves, which eventually turn brown; the diseased leaves show mosaic of light green and evergreen; in severe cases, the leaves become deformed and yellow, the plants become short, the flower spikes are short, the flowers are small and few, or even flower spikes cannot be produced.

Prevention and treatment methods

Remove leaves infected by mosaic disease bacteria and then use pesticides for prevention and control. The pesticide can be sprayed with 2500 times diluted 50% benomyl wettable powder for prevention and control.

Common diseases of Clerodendrum thomsoniae: Botrytis cinerea

Symptoms

It can harm the stems, leaves and flowers of the plant, mainly the flowers. Pathogens invade through weakened host tissues. The leaves are affected, often first at the tip or edge of the leaves. In the early stage of the disease, water-like spots appear on the diseased part, which gradually expand and the diseased tissue turns black-brown and rots.

Prevention and treatment methods

Remove diseased flowers and leaves promptly and burn them in a concentrated manner to reduce the source of infection. The greenhouse should be well ventilated, watering should not be excessive, and the indoor temperature and humidity should be controlled.

In the early stage of the disease, you can use 800-1000 times diluted 70% thiophanate-methyl wettable powder or 800-1000 times diluted 50% carbendazim wettable powder for spraying for prevention and control. Spray once a week, for 2 to 3 times in a row.