Powdery mildew is the main disease of calendula, which seriously affects its ornamental. At the early stage of the disease, the white round spots appeared on both sides of the leaves, and the irregular round spots appeared further. The leaves looked like a layer of white powder, and the stems were also covered with white powder. At last, the diseased leaves and stems turn yellow and the whole plant withers and dies.
Strengthen water and fertilizer conservation and enhance the disease resistance of plants. The plants for indoor maintenance should be ventilated in time, especially in March to April. When the weather turns warm, they should be moved to the outside in time to reduce the humidity.
When the flowers fall behind, the fallen leaves and flowers shall be removed in time, and the sick plants shall be built.
After the onset of the disease, spray the medicine in time. When spraying, spray the whole plant. Spray once every 10-15 days, 2-3 times continuously.
Mosaic disease mainly damages leaves. After suffering from this disease, leaves will form mottled or flowered leaves, leaves will turn yellow, plant growth will be blocked and dwarfed, and flowers will grow abnormally. Mosaic is mainly transmitted by insects, which are often accompanied by pests.
It was found that the diseased plants were pulled out in time. At present, there is no specific drug for the prevention and control of mosaic, so the prevention and control of mosaic is mainly based on pest prevention, and fungicides are sprayed every month.
When the temperature rises in early summer, Calendula often appears rust. Rust spots will appear on the leaves, resulting in defoliation, scorched shoots, poor growth, etc. In severe cases, the spores are piled up tightly, and Calendula is rapidly withered due to the evaporation of a large amount of water in the body.
Spray the agent in time and spray it with 2000 times of 50% weixiangling wettable powder. Once rust spots are found on the leaves, remove the leaves in time to avoid infecting other leaves.
