[Edit this paragraph] Basic symptoms
Also known as botrytis cinerea. Harm leaves, buds, stems and flowers. Infection at the top of young stems and young leaves leads to softening and rot of the growing points of stems; The leaves are infected, forming yellow to reddish brown round or oval spots, and the surrounding areas of the spots are soaked in water. When the humidity is high, botrytis cinerea layer, that is, conidiophore and conidia of pathogenic bacteria, is produced at the diseased site. In the hot and dry season, the lesion is thin and light brown. With the spread of the disease, the lesion gradually expanded, resulting in the whole leaf dying. When the bud is infected, it produces small brown spots, which causes the bud to swell and rot. In severe cases, many buds stick together. When the humidity is high, a large number of gray mold will appear in the affected area, and black fine H-shaped sclerotia can be seen in the affected area in the later stage. The dyed part of the stem began to turn brown or constricted and turned upside down; Individual bulbs are infected and lead to rot.
[Edit this paragraph] Etiology principle
Botrytis elliptica ) Cooke is called Botrytis elliptica and belongs to the subfamily Hemifungi. Conidiophore is erect, light brown to brown, with three or more septa, three or more branches at the top, and many conidia at the top of the branches; Conidia are colorless to light brown, ovoid to ovoid, single spherical, with a size of 65,438+06-35× 65,438+00-24 (micron) and a pointed end. Black sclerotia is very small, with a diameter of 0.5-1mm. In addition, it is reported that botrytis cinerea also refers to the cause of the disease. The difference between two kinds of grape spores: the former conidia are oval and large; The latter is oval and smaller. Zhejiang report B. liliorumhino said that botrytis cinerea of lily was also the pathogen of the disease. The Transmission Pathway and Pathogenic Conditions of conidiophore and Conidia; The pathogen overwinters in the damaged part of the host with mycelium or in the soil with sclerotia. In the spring of the following year, with the increase of temperature, overwintering hyphae produced conidiophore and conidia in susceptible areas, which caused primary infection through airflow transmission; After the disease occurs in the field, conidia are produced in the affected area for re-infection. The optimum temperature for the growth of pathogenic bacteria is 22-25℃. When there is more rain and fog in the field and the relative humidity is higher than 90%, the disease spreads faster.
[Edit this paragraph] Prevention and control methods
(1) Choose healthy and disease-free bulbs for propagation, and pay attention to ventilation and light transmission in the field or greenhouse to avoid over-dense planting, promote plant health and enhance disease resistance. (2) In winter or after harvest, the diseased plants should be removed and burned, and the diseased leaves and flowers should be removed in time to reduce the source of bacteria. (3) spraying 400 times of 30% basic copper sulfate suspension or 500 times of 36% thiophanate-methyl suspension, 700-800 times of 60% Mujiaobao No.2 water-soluble powder, 1500 times of 50% benomyl wettable powder, 2000 times of 50% prochloraz wettable powder, 50% iprodione (iprodione). Stop taking medicine 3 days before harvest.