Control methods of leaf spot and anthracnose of sunflower

Aquilaria is a common green plant in family and office area. Summarizing the experience of flower friends, it is found that leaf spot disease and anthracnose disease often occur in the cultivation process of Aquilaria. The symptoms and prevention methods of these two diseases are briefly introduced.

Colletotrichum gloeosporioides:

1. Symptoms: After the occurrence of Colletotrichum gloeosporioides, the disease mostly occurs from the leaf edge and leaf tip. Spot round, semicircular or irregular shape, brown to black, disease slightly raised, yellow halo edge. Later on the lesion produced a small black.

2. Occurrence rule: Pathogen overwinters in the diseased leaf residue on the ground or in the diseased leaf on the plant. When the conditions are suitable in the following year, conidia are formed, transmitted by wind and rain, and infected. The disease can occur from March to October. Plants lack fertilizer and water, grow weak, or plant roots hurt, are easy to susceptible to disease. High temperature and humidity are conducive to the expansion and spread of diseases.

3. Prevention and control methods:

(l)50% thiophanate-methyl WP 800 times solution and 75% chlorothalonil WP 800 times solution can be sprayed from the early stage of disease.

(2)Remove the diseased leaves and burn them in the soil to eliminate the overwintering bacteria.

(3)Plastic shed or greenhouse, can try to use 45% chlorothalonil smoke agent or 8% ketanling dust agent.

(4)Strengthen the management of water and fertilizer, enhance the disease resistance of plants.

leaf spot disease:

1. Symptoms: Yellow-brown spots appear in the early stage of leaf disease, gradually expand into stripes, and can merge into irregular necrotic masses. Leaf tip, leaf edge most vulnerable, serious disease, most leaves have more than half dry curl, such as fire; dark or gray center of the disease spot, surrounded by dark lines, late disease scattered oval small black spots. The control methods of leaf spot disease and anthracnose disease of Aquilaria oleracea are common green plants in families and office areas. Summarizing the experience of flower friends, it is found that leaf spot disease and anthracnose disease often occur in the cultivation process of Aquilaria oleracea. The symptoms and control methods of these two diseases are briefly introduced. Colletotrichum gloeosporioides: 1. Symptoms: After the occurrence of Colletotrichum gloeosporioides, the disease mostly occurs from the leaf edge and leaf tip. Spot round, semicircular or irregular shape, brown to black, disease slightly raised, yellow halo edge. Later on the lesion produced a small black. 2. Occurrence rule: Pathogen overwinters in the diseased leaf residue on the ground or in the diseased leaf on the plant. When the conditions are suitable in the next year, conidia are formed, transmitted by wind and rain, and infected. The disease can occur from March to October. Plants lack fertilizer and water, grow weak, or plant roots hurt, are easy to susceptible to disease. High temperature and humidity are conducive to the expansion and spread of diseases. 3. Control methods: (1) From the early stage of the disease, 50% thiophanate-methyl WP 800 times solution and 75% chlorothalonil WP 800 times solution can be sprayed. (2)Remove the diseased leaves and burn them in the soil to eliminate the overwintering bacteria. (3)Plastic shed or greenhouse, can try to use 45% chlorothalonil smoke agent or 8% ketanling dust agent. (4)Strengthen the management of water and fertilizer, enhance the disease resistance of plants. Discolored sunflower leaf spot disease: 1. Symptoms: Yellow-brown spots appear in the early stage of leaf disease, gradually expand into stripes, and can merge into irregular necrotic blocks. Leaf tip, leaf edge most vulnerable, serious disease, most leaves have more than half of the dry curl, such as fire; dark or gray center of the lesion, surrounded by dark lines, late disease scattered oval small black spots. 2. Occurrence rule: The disease generally occurs from May to November. High temperature and rain are conducive to the spread of disease. 3. Control methods: (1) Strengthen nursery management: proper shade should be avoided during seedling raising. (2)Rational fertilization: do not bias nitrogen fertilizer, potassium fertilizer should be increased. (3)Timely chemical control: spraying 50% captan wettable powder 300~500 times at the early stage of the disease, or using 70% mancozeb wettable powder 400~650 times, once a week, several times in succession, can effectively control the disease. Symptoms and control methods of leaf spot disease of Aquilaria oleracea

Anthrax pathogen: Colletotrichum sp. Symptoms: The disease occurs on the horseradish, affecting the viewing effect. At the beginning of the disease, small chlorotic spots appeared on the leaves, which were nearly round spots, light brown, 5~12mm in diameter after expansion, and at the end of the disease, the central tissue was gray, the edge of the spots was reddish brown, and the width was about 1 mm. There are yellow dots outside the spots.

Gray spot pathogen: Pestalotiopsis palmarum(Cooke) Steyaert Symptoms: The disease mainly damages mature leaves, causing leaf blight, affecting the sale and viewing of commodities. At the beginning of the disease, small brown spots appeared on the leaf margin and leaf surface, and after expansion, they were mostly semi-elliptical or irregular spots, dark brown, different sizes, and yellow halo outside the spots. At the later stage of the disease, the disease spots merged into large spots, making the leaves 1/4~1/2 yellow or longer. When humidity is high, black dots are scattered on it.

Leaf blight pathogen: Pseudoareca leaf spot mold (Phyllosticta caryotaeShen) causes symptoms: the disease forms large spots on the leaves, affecting the viewing. At the beginning of the disease, strip-shaped white spots appeared on the leaf margin or leaf surface, which expanded into strip-shaped irregular spots, withered white, brown spots. Lesions are limited in their extension by veins.

the prevention and control method comprise that following step: 1) cultivation technology for preventing diseases: timely cutting off and deeply bury diseased leaves; paying attention to water control in four seasons: watering once every 10 to 15 days when the temperature is lower than 10 DEG C, watering once every 4 to 5 days when the temperature is lower than 20 DEG C, watering according to weather conditions in summer, and spraying water to cool down; applying nitrogen fertilizer without bias, and the ratio of nitrogen, phosphorus and potassium is generally 1:1: 1.2) chemical protection: protective agent: dicyananthraquinone, propafenone zinc, mancozeb therapeutic agent: propiconazole, difenoconazole, prochloraz, myclobutanil, etc.

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