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How is the condition of Euonymus japonicus disease? Let us help you recognize the common disease symptoms

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1. Symptoms: In the early stage of the disease, there are small yellow spots on the leaves, which gradually turn yellowish-brown and expand into round or irregular spots. The diameter of the spots is 2 mm to 10 mm. In the later stage, the spots become grayish-brown or grayish-white, with darker edges, and many small black dots form on the spots. In severe cases, the spots merge into one large area, and the leaves turn yellow and fall off. 2. Disease pattern: The pathogen overwinters in the form of mycelium and other structures on diseased leaves or fallen leaves, serving as the primary infection source. Spores are spread by wind and rain. In the spring of the following year, as the temperature rises, conidia are produced,

1. Symptoms: In the early stage of the disease, there are small yellow spots on the leaves, which gradually turn yellowish-brown and expand into round or irregular spots. The diameter of the spots is 2 mm to 10 mm. In the later stage, the spots become grayish-brown or grayish-white, with darker edges, and many small black dots form on the spots. In severe cases, the spots merge into one large area, and the leaves turn yellow and fall off.

2. Disease pattern: The pathogen overwinters in the form of mycelium and other structures on diseased leaves or fallen leaves, serving as the primary infection source. Spores are spread by wind and rain. In the spring of the following year, as the temperature rises, conidia are produced and invade through stomata, pruning cuts, or wounds. In the Hebei region, infection generally begins in June, with July and August being the peak infection period. Symptoms appear in mid-August, and the disease is severe from mid-to-late August to September, with spots expanding and leaf drop occurring. The severity of the disease is directly related to temperature and the amount of rainfall. Generally, years with high temperature, abundant rain, and humid conditions have severe disease occurrence. Euonymus japonicus leaf spot disease is prone to occurring together with scale insects and aphids, which worsens the condition of the plant. When management is extensive, drainage is poor, planting is too dense, and ventilation is poor, the disease is more likely to occur.

3. Control measures: Following the principle of "prevention first, combining prevention and control." Start with plant selection, planting, and management to enhance plant disease resistance. When disease occurs, treat it early, treat it when minor, and treat it thoroughly to inhibit its development.

1. Eliminate infection sources: In winter, remove diseased fallen leaves, burn or bury them deeply, and eliminate the infection source.

2. When planting and raising seedlings, select robust plants to improve disease resistance.

3. Strengthen maintenance and management: Choose plots with good drainage and moderate fertility to facilitate plant growth, strengthen tree vigor, and improve disease resistance. Plant at a reasonable density, pay attention to ventilation and light penetration, reduce leaf surface humidity, and decrease the incidence of disease.

4. Chemical control: The early stage of pathogen infection is the best time for control. At this time, applying chemical control to Euonymus japonicus can effectively control further disease development. Common chemical agents include Bikengsha 800-1000 times solution, 75% thiophanate 1500 times solution, 50% carbendazim and 75% chlorothalonil 500 times solution. Chemical agents should be used alternately, sprayed once every 7 to 10 days, with 2 to 3 consecutive applications for good results. In the middle and late stages of disease occurrence, Penkengjun 2000-3000 times solution can be used, sprayed once every 7 to 10 days, and 2 to 3 consecutive applications can promptly control the disease. Other agents that can also be used include Amistar, kresoxim-methyl, and others.

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