Symptoms: This is one of the diseases of Rhododendron, which will occur in the plum rain season. At the beginning, there will be some small brown spots on the leaf surface, which will become irregular spots, causing the leaves to turn yellow, leading to falling off, affecting the flowering of the year and the development of flower buds in the next year.
Prevention and control: when planting, we need to pay attention to ventilation and light transmission of Rhododendron, so as to reduce the possibility of disease. If the diseased leaves are found, they need to be removed in time, and then burned together. In the early stage of the disease, a little Bordeaux can be sprayed.
Symptoms: the disease mainly occurs in the alkali soil area. When the disease is mild, it will only lead to the lack of green plants. If it is serious, it will lead to the scorching of the edge of leaves, which is a big problem for ornamental.
Prevention and control: start from the source, reduce the alkalinity of the soil, spray a little acid material, and effectively increase the acidity of the soil.
Symptoms: This is one of the common pests of Rhododendron, which often sucks juice on the back of the leaves, and finally causes the leaves to fall off, which is common in the very dry weather in summer.
Prevention and control: spray once in late October and early spring around March.
