The latest common diseases of rhododendron and their control

The western rhododendron is a kind of fiery red flower. It has many flowers and colors, but it is mainly fiery red. It is very harsh to the growth environment. It must be warm, moist and fertile soil. As long as it grows improperly, there will be problems. And it is also easy to cause diseases and insect pests. Many flower friends also have headaches when they encounter diseases and insect pests. They do not know what to do. They can only watch the western rhododendron die. Then Shuai Shuai will tell you about some common diseases and insect pests of rhododendron and their prevention and control methods.

1. Brown spot

1. Brown spot is a disease specially harmful to plant leaves with a high incidence of western rhododendron. This disease may occur in almost all varieties of cultivation areas. This disease is a spreading virus. At the beginning, the initial symptoms of the disease are shown as a small round spot, and slowly this round spot will spread rapidly, slowly forming a spot area. Finally, it expands into a round, rectangular or irregularly shaped lesion area, and finally spreads to the whole leaf, swallowing the whole leaf, and then the leaf falls off. This disease spot is mainly damaged by fungi, the bacteria come from the disease remains in the soil, when overwintering, these disease residues will produce vegetative forms, spread by air, from the plant stomata, or wounds invade the plant body.

2. Control measures: once the diseased leaves of Jiujiang were removed and buried deep in the ground, the solution of ferrous sulfate was sprayed or irrigated to adjust the pH of the soil. Strengthen the management of the field, enhance the disease resistance of plants, keep the soil moist, loose and breathable, do not let the basin bottom stagnant water, cultivate strong plants, enhance disease resistance.

Second, blight disease

1. Rhizoctonia solanacearum is a kind of disease spot that harms the stem, and the disease develops slowly, which will slowly dry up the stem and produce hyphae when the humidity increases, which may form sclerotia of different sizes and brown. This disease is also caused by fungi. As long as the temperature picks up in the humid season, it will provide an environment for it to grow. It will slowly damage the plants, generally due to high soil water content and plenty of sunlight. So we should pay attention to the control of moisture when we breed.

2. Prevention and control measures: the most important thing is the control of temperature and humidity, and heat preservation measures should be taken at low temperature, so as not to reduce the immune ability of the plant caused by freezing and be invaded by bacteria. When the humidity is high, it is necessary to ventilate more air and not provide an environment for the bacteria to grow.

3. Red leaf disease

1. Red leaf disease is a physiological disease, which shows dark red dots on the leaves at the beginning of the disease, and then slowly spreads on the leaves, and the color deepens slowly with the increase of the area, but the veins remain green. Slowly the whole leaf turns red. This disease is caused by the lack of magnesium, which is an important element in the life activities of plants. If the lack of magnesium will affect the growth of plants, and photosynthesis will also be affected and hindered, the immunity of plants will decline, and eventually lead to the invasion of other bacteria.

2. Prevention and control measures: the key point of prevention and control of red leaf disease is to improve the immune ability of the plant, so that it can resist the invasion of bacteria itself, and increase light to promote its photosynthesis on weekdays, so that it can accelerate its new metabolism. In the early stage of the disease, foliar spray of 1500 ~ 2000 times magnesium sulfate solution can be used for 3 times.

The above are the common diseases and control methods of rhododendron. Have you learned it? In fact, the diseases of the western rhododendron are far more than these. Shuai Shuai only listed a few of the most common and common diseases here. These diseases are also the most common diseases of the western rhododendron, so we must carry out prevention and control in accordance with the above methods, otherwise we will be in trouble as soon as we catch the germs.