Leaf spot mainly damages the leaves and twigs of peony. The incidence of the disease is generally about 15 days after flowering, the most serious in mid July. In the early stage, there will be black spots on the back of the leaves with large grains, and the edges will be black, and the disease spots will gradually connect, leading to the withering and withering of the leaves.
Solution: do a good job in prevention, spray Bordeaux liquid in time after flower falling, once every 10-15 days, until the end of July. It can avoid the occurrence of leaf spot. At the onset of the disease, metformin and carbendazim solution were sprayed once every 7-10 days for 3-4 times.
The yellow leaf disease of peony is mainly caused by the lack of phosphorus in the plant, which is manifested in that the plant grows short and the leaves turn yellow. It starts from the old leaves at the stem base and gradually falls off from the bottom to the top.
Solution: supplement nutrients in time, spray potassium dihydrogen phosphate or micro fertilizer on leaves after flowering.
Sclerotinia disease is also called stem rot, which mainly damages the rhizome and causes it to rot. At the time of disease, there were water stains on the stems and white cotton on the soil surface. Serious damage to flower buds and leaves.
Solution: do a good job in disinfection, disinfect the soil before planting plants, and plant after drying. Avoid excessive moisture in the soil during maintenance, so as not to breed bacteria. When the plant is ill, the plant shall be dug out and replanted after disinfection. If the decay is serious, it can be thrown away directly.
Purple feather disease is a fungal disease, which mainly damages root neck and root. The damaged part will appear purple or white floccules with black edges. The light ones will form patchy patches, the roots will not grow, the branches will be thin and the leaves will turn yellow, and the plants will die in serious cases. The disease usually occurs in June to August, and after September, with the decrease of temperature and rainfall, it gradually decreases.
Solution: pay attention to the cleanliness of the maintenance environment to avoid the breeding of bacteria in the environment. In hot and rainy weather, reduce watering and ventilate frequently. For the affected plants, lime or sulfur can be sprinkled on the soil surface for disinfection. If it is serious, the plants shall be replanted in the basin.
