Control methods of Brown spot of Rhododendron

Jian Liu Maohua, Jiangxi: I have raised azaleas for several years and can grasp their growth habits, but to May-June, they still often have brown spot, which is difficult to control in many ways, but are there any clever tricks?

Answer l: the cuckoo I raised also had this problem, and spraying fungicides didn't help. Later, I analyzed that it may be related to the excessive consumption of nutrients and the reduction of plant resistance. So the following measures are taken:-to remove half the buds, and second, to remove the open flowers at a slight failure-in order to achieve a balance between flowering and recuperation, that is, nutrient consumption is less than nutrient absorption. As a result, the leaves remained clean and green all the time, and the incidence of brown spot was greatly reduced, but there were still a small number of diseased leaves, which mainly occurred after anthesis and were soon renewed by new leaves. (Jilin Fangzhaojun)

Prevention and control methods of rhododendron brown spot Jiangxi Jian Liu Maohua: I have raised azaleas for several decades and can grasp their growth habits, but from May to June, they still often have brown spot, which is difficult to control with many methods. Answer 1: the cuckoo I raised also had this problem, and spraying fungicides didn't help. Later, I analyzed that it may be related to the excessive consumption of nutrients and the reduction of plant resistance. So such measures are taken: one is to remove half the buds, and the other is to remove the open flowers at a slight failure-in order to achieve a balance between flowering and recuperation, that is, nutrient consumption is less than nutrient absorption. As a result, the leaves remained clean and green all the time, and the incidence of brown spot was greatly reduced, but there were still a small number of diseased leaves, which mainly occurred after anthesis and were soon renewed by new leaves. (Jilin Fangzhaojun) what if the azaleas get brown spot? Prevention and control of rhododendron brown spot Azalea, also known as Yingshanhong, pomegranate, is an evergreen or ordinary green shrub. According to legend, in ancient times, there were cuckoos, whining day and night and hemoptysis, dyed red flowers all over the mountain, hence the name. Azaleas generally bloom in spring, each cluster of 2-6 flowers, Corolla funnel-shaped, there are red, light red, apricot red, snow blue, white and so on. If rhododendron is not properly managed in the process of growth, it is easy to lead to root rot, brown spot, black spot, leaf blight and iron deficiency chlorosis. This paper focuses on the prevention and control of rhododendron brown spot for your reference and study. Brown spot is a major disease of rhododendron. At the beginning of the disease, small brown spots appeared on the leaf surface, which gradually developed into irregular spots, and many black or grayish brown spots were produced on the disease spots, which made the damaged leaves yellow and fall off, affecting the flowering of the current year and the development of flower buds in the coming year. This disease often occurs during the rainy season when the humidity is high. Prevention and treatment: sweep and burn the fallen leaves in time in winter and spring. After leaf spreading, Bordeaux solution (1-1-1-100) was sprayed every half a month, which could be sprayed 2-3 times continuously to prevent the disease. 1000 times of 50% methyl topiramate wettable powder was sprayed 1-2 times in the early stage of the disease to inhibit the development of the disease. In addition, we should also pay attention to make the plant ventilated and transparent, do not have too much humidity, and increase the application of organic fertilizer and nitrogen, phosphorus and potassium mixed fertilizer to enhance the plant resistance to infection and growth. In addition, according to the analysis of flower friends, the brown spot disease may be related to the excessive consumption of nutrients and the decrease of plant resistance. To solve this problem, measures have been taken: one is to remove half of the buds, and the other is to remove the open flowers at a slight failure-in order to achieve a balance between flowering and rest, that is, nutrient consumption is less than nutrient absorption. As a result, the leaves remained clean and green all the time, and the incidence of brown spot was greatly reduced, but there were still a small number of diseased leaves, which mainly occurred after anthesis and were soon renewed by new leaves. Conclusion: the above is the introduction of the prevention and control methods of rhododendron brown spot disease. I hope it will be helpful to the friends who plant azaleas.