Control of Botrytis cinerea in Carnation

Gray mold of carnation, also known as carnation blight, is a common disease of growing carnation in greenhouse and greenhouse. The disease harms the petals of the plant, causes brown spots and rot on the petals, and seriously affects the quality of cut flowers.

Symptoms: the disease mainly occurs on petals and buds, and occasionally occurs in stems and leaves. At the beginning of the disease, the susceptible flowers began to appear light brown water stains from the edge of the petals, and then several petals were entangled by gray fungi. In the later stage of the disease, if the environment is moist and the petals rot, a gray powdery mildew layer is produced on it, which is the conidia of the pathogen. Finally, the diseased flowers withered and died, and the diseased flowers could remain on the plant for a long time after they dried up. Waterlogged irregular spots are produced on the susceptible buds, which are soft and rotten, resulting in the flowers can not open, and a gray powdery mildew layer is also produced on them.

Pathogen: the pathogen is Botrytis cinerea (BotrytiscinereaPers.), which belongs to the subphylum Trichoderma, Trichospora, Trichospora and Botrytis.

Disease regularity: the pathogen overwintered with sclerotia in the remnant of the diseased plant or in the soil. When the conditions were suitable in the spring of the second year, conidia were produced for infection. When the temperature is about 20 ℃ and the humidity is very high, the disease occurs seriously. Low temperature and high humidity in early spring and late autumn often lead to the occurrence of this disease. The disease resistance of tissue culture seedlings was better than that of cutting seedlings. Safflower varieties are more resistant to disease than yellow ones.

Prevention and treatment: ① reduces the source of infection: remove susceptible plants and flowers in time and destroy them immediately. ② strengthens cultivation management: increase mild ventilation to keep the humidity in the greenhouse low. When watering, avoid leaving water film on the petals. ③ chemical control: spray 75% chlorothalonil wettable powder 500x liquid or 50% carbendazim wettable powder 500x liquid before the disease or cut flowers.