The rust of Metasequoia occurs in spring. After the disease, the yellow brown powdery summer spores can be observed on the back of leaves, petioles and veins of leaves. When the fungus invades the plants, the branches and leaves will lose their green and turn yellow. There are protruding spores on the surface of the disease spots. In serious cases, the leaves of the whole plant will wither and fall off and the flower buds will dry and fall off.
Prune frequently and remove the rusty branches and leaves in time; apply nitrogen, phosphorus and potassium fertilizer reasonably to prevent excessive growth and enhance the resistance of the plant; pay attention to ventilation and light transmission, do well in drainage work, reduce the temperature, and create a suitable growth environment for the plant..
The larvae of coffee beetle moth will moth into the stem of Metasequoia glyptostroboides, nibble the vascular bundle of the stem, causing the branches to wither and die, making the plants unable to grow and bloom normally, and breaking the stem when it is seriously mothed.
If there are not many insects, cut off the damaged twigs and burn the dead branches. If there is a large outbreak of insects, consider using chemical pesticides. Inject 200 times diluted Omethoate solution into the wormhole to kill the larvae.
Rosette wasps can produce two generations in one year, and the larvae usually cocoon in the soil for overwintering. Rose leaf wasps have the habit of clustering. When serious, they can eat up the leaves and leave only the veins. The female lays her eggs on the shoot, which can wither.
The branches with hatching larvae were removed by artificial leafing, and trichlorfon solution diluted 1000 times or deltamethrin solution diluted 2000 times were sprayed.
The propagation cycle of leaf Chan is short, 5-6 generations can occur in one year. Cicadas use their mouths to prick and suck sap, which makes the leaves appear light white spots. When the damage is serious, the spots will spread into patches, causing the branches and leaves to wither.
In winter, the nursery should be cleaned up in time to reduce the source of overwintering insects.
