Common Diseases of Tree Peonies—Anthracnose

  Common Diseases of Tree Peonies—Anthracnose

  Tree peony anthracnose is one of the common diseases of peonies, with a wide range of impacts and great harm, and should be prevented and treated in a timely manner.

  Pathogen of Tree Peony Anthrax:The pathogen is a type of anthrax fungus (Colletotrichum SP.)

  Symptoms of Tree Peony Anthrax:

  Mainly damaging leaves, flower stems, petioles, and tender branches. When the leaves are infected, brown small spots appear on the surface of the leaf, gradually expanding into circular to irregular large spots, generally ranging in size from 4-25mm. The spots that occur at the edge of the leaf are semi-circular, and the expansion of the spots is limited by the main and lateral veins. The spots are mostly brown, and some varieties have gray white spots in the center of the leaf spots and yellow brown edges. In the later stage, the center of the spots cracks, sometimes in a perforated shape. In July and August, black small granules arranged in a wheel shape grow on the spots, which are the conidia discs of the pathogenic bacteria. When the humidity is high, reddish brown sticky spore clusters overflow from the conidia discs, becoming the characteristic symptoms for identifying the disease. The tender stem, flower stem, and flower stem are infected and produce spindle shaped slightly depressed spots, which are reddish brown in color, measuring 3-7mm in size, and later gray brown in color with reddish brown edges.

  The incidence pattern of tree peony anthracnose disease:

  Pathogenic bacteria overwinter in diseased plants as mycelium, and the mycelium that overwinters in suitable environments the following year produces conidia discs and conidia; Under rain and dew, conidia spread and germinate; In years with high temperatures and heavy rainfall, the incidence of the disease is more severe, usually peaking in August and September when there is more rainfall.

  Prevention and control methods for tree peony anthracnose:

   ① Promptly bury or burn the diseased or disabled body.

   ② Pay attention to ventilation and timely drainage during the rainy season.

   ③ In the early stages of the disease, 70% mancozeb 500 fold solution or 80% anthracnose Fumei 500 fold solution can be sprayed once every 10-15 days for two consecutive sprays.