Disease and Pest Control of Rhododendron velutipes

one. Leaf swell

Leaf swelling is one of the common diseases of azalea flowers, also known as leaf cake disease. Leaf swelling disease mainly attacks the young leaves and flower buds of Rhododendron aviculare, including all new and tender tissues. The symptoms of leaf swollen disease are translucent yellow circular patches on the front of the leaves, light red on the back of the leaves and enlarged leaves. The flower buds will become abnormally thick after being infected. In severe cases, the disease may cause the affected parts to dry up and fall off. The prevention and control method is also very simple. Before the leaf swelling disease occurs, you can spray Bordeaux liquid with a concentration of 1:1:200. If leaves with leaf swelling disease are found, they need to be removed. Before germination, it is also necessary to spray 1:1:200 Bordeaux mixture 2-3 times, generally once every seven to ten days; if it is found that it has leaf swelling disease, it is necessary to spray 65-80% mancozeb 500 times solution or 0.3-0.5 degrees Baume lime sulfur mixture 3-4 times, generally once every seven to ten days.

two. Leaf spot

Leaf spot disease has another name called brown spot disease. Surprisingly, its symptom is that it will turn the leaves into reddish brown, and in severe cases, into black brown. The method for prevention and control of leaf spot disease is to spray 1000 times diluted 70% thiophanate-methyl, 4000 times diluted 20% triadimefon, and 500 times diluted 50% mancozeb between May and August every year. Generally, spray once every ten days, and a total of seven or eight times are required. This is the only way to curb the development of the disease.

three. Currency sickness

The disease is caused by aphids biting the leaves and flowers, so the most important thing is to kill the aphids. The symptom of mites disease is that the flowers and leaves will be covered with a layer of mites. In severe cases, it will cause the flowers and leaves to dry up, affecting the ornamental value of Rhododendron azalea. The method to prevent and control this disease is to remove the diseased leaves in time and spray medicine containing copper sulfate in time to kill aphids.

The diseases and pests of Rhododendron camara are actually very easy to prevent and control. The most important thing is to always pay attention to the growth status of the flowers, discover the disease, prescribe the right medicine, and remove it in time.