Powdery mildew
Powdery mildew is a common disease of lilies, which mainly damages leaves, pedicels and buds of plants. When Dahlia has powdery mildew, it will appear pathological changes on the plant. It is a round layer of powdery mildew, causing the leaves to twist and wither.
Xiaolihua's powdery mildew usually occurs in September and October. When the disease occurs, you can spray some medicaments, such as the diluted solution of antimycin or the diluted solution of polysulfide gum suspension, etc. for several times, it will have therapeutic effect.
Brown spot disease.
Brown spot is also a common disease of Dahlia. When it occurs, it mainly infects the leaves, has yellow spots, and gradually expands. It also produces black mold on the surface of the leaves.
When Dahlia develops melasma, it is usually from June to August. It can be treated with Bordeaux solution or chlorothalonil solution.
Viral disease
Virus disease is also a common disease of lilies, mainly manifested as chlorosis of flowers and leaves, plant Dwarfing and other diseases.
Xiaolihua virus disease is mainly caused by infection with some viruses. In the cultivation of lilies, cry to choose some non - pest planting materials, to prevent pests.
Moth larvae
The common pest of dahlia is the moth larva. The larva is light yellow or light red. The damage period is mainly from June to August.
Control method
When dahlia is damaged by moth larvae, it can be treated by spraying some fungicides. You can also inject Omethoate.
