Disease and Pest Control of Verbena Slenderleaf

1. Powdery mildew

This disease mainly harms the leaves of flowers, and sometimes the stems and petioles are also affected. In the early stage of the disease, white spots will appear on the surface of the leaves, and its spreading ability is very strong, and all the spots can be connected into one in a very short time. If left untreated for a long time, the leaves will slowly turn yellow and wither. This disease is very likely to occur when the air circulation is poor, the environment is too humid, and the temperature is too high.

Prevention and control: After the disease occurs, you can first prune off the branches and leaves that are seriously affected by the disease. At the same time, spray with medicine and increase the application of phosphorus and potassium fertilizers. After winter, all diseased branches and leaves can be cut off and cleaned up. During daily maintenance, be sure to place it in a place with good air circulation. In summer, you can use a fan to increase ventilation.

2. Botrytis cinerea

The disease mainly occurs in the flowers. Initially, small spots will appear on the flowers, and then slowly spread, causing the entire flower to change color and rot; its leaves are also affected, in the same condition as the flowers. This disease is also easy to occur in an overly humid environment, and the disease can remain dormant in winter and recur the following year.

Prevention and control: In the early stage of the disease, the diseased flowers and leaves should be cut off and destroyed, and then drugs should be used to control the disease and reduce the surrounding humidity; watering should be done in the morning as much as possible.