Common Tree Peony Diseases - Red Spot Disease

Common Tree Peony Diseases - Red Spot Disease

  Symptom: It often causes premature withering of leaves, affecting the growth potential of peonies. It mainly harms the leaves of peonies and also infects branches, flower organs, seeds, and other parts. At the beginning of the disease, large, nearly circular or irregular spots appear on the leaf blades, and both sides of the lesion are brown in color; When seriously ill, the convergence of disease spots causes leaf blight and distortion, and under humid conditions, a dark green mold layer grows on the back of the disease spots. After infection of the stem and petiole, long strip-shaped disease spots appear, purple brown in color, slightly raised in the early stage and slightly depressed in the later stage. The center of the disease spot cracks, and when the disease spot occurs at the branching point of the branch, the affected area is prone to breakage. The diseased spots on the floral organ are small brown spots, and when seriously ill, the edges of the petals become scorched.

  Prevention and control methods:

  Reduce the source of infection: Thoroughly remove the diseased remains on the ground in autumn.

  Chemical control: Spray 50% carbendazim at 600 times dilution or 3 degrees sulfur solution on plants before sprouting in early spring to kill bacteria. Spray 50% carbendazim 1000 fold solution or 65% mancozeb 500-600 fold solution once every 7-10 days after onset, continuously spraying 3-4 times.

  Strengthen cultivation management: moderate planting density, apply organic fertilizer and compound fertilizer.