The prevention and control methods of hyacinth white silk disease and carnation white silk disease, what are the symptoms of white silk disease?

[symptoms] the whole plant withered, the stem base was wrapped around white fungal cords or rapeseed tea-brown sclerotia, and the affected part became brown and rotten. A large number of white fungal cords and tea-brown sclerotia can be seen on the soil surface. The disease occurs at the base of the stem near the soil surface and turns brown and rotten. The diseased stem tissue was cut and tea-brown or dark-brown rot developed to the center from the outside; the xylem also changed color upward, and the pinnately radiating white hyphae could spread to the surrounding soil surface; then sclerotia were formed on the mycelia of the diseased part and the surrounding soil surface, which were initially white and then turned yellowish brown to the size of rapeseed. After the plant is susceptible to disease, the whole plant usually loses and dies. On the cutting bed, wet rot occurs from the healing and forming area of the cuttings, which can also cause serious root neck rot.

[incidence regularity] the bacteria overwintered in the soil with sclerotia or bacteriocin. When the conditions are suitable in the following year, the sclerotia or mycelium will produce hyphae for primary infection. The silky filamentous hyphae produced by diseased plants extend to contact with adjacent plants or sclerotia are re-infected by water transmission, resulting in the spread of the disease. Continuous cropping or clay weight of soil and low-lying or high-temperature, wet years or seasons. The pathogen has a wide range of hosts, which can harm dozens of plants, such as cactus, orchid, squirrel tail, melon leaf chrysanthemum, chrysanthemum, goldfish grass, Persian chrysanthemum, marble chrysanthemum, iris, tulip, hyacinth, lily, Hosta and so on. Bacteria exist as mycelium or sclerotia residues in diseased bodies, diseased plants, wild plants and soil. Sclerotia can survive for 3-4 years in soil, but it is very short in water and wet soil. High humidity is beneficial to the spread of bacteria, and the disease occurs in summer.

[control methods] ① should avoid continuous cropping with susceptible plants; the base fertilizer should be fully mature so as not to carry bacteria; it should be properly ventilated to avoid planting too dense. It was found that the diseased plants were removed and burned in time, and the diseased point and its adjacent plants were irrigated with 5% Jinggangmycin water agent 1000-1600 times or 50% Tianan water agent 500 times 600 times, 20% methyl rifampicin EC 1000 times, and 90% dimethophos wettable powder 1000 times. Combined with ploughing, the soil was slightly alkalized by adding 100~150kg lime powder every 667 m ², which could inhibit the breeding of Alternaria alternata.

Prevention and control of carnation white silk disease

Shanghai, Hangzhou.

[symptoms] the disease occurs at the base of the stem near the soil surface and turns brown and rotten; the diseased stem tissue is cut and tea-brown or dark-brown rot develops to the center from the outside; the xylem also changes color upward, and the pinnately radiating white hyphae can spread to the surrounding soil surface; then sclerotia the size of initially white and later yellowish-brown rapeseed is formed on the diseased part and surrounding soil surface mycelia. After the plant is susceptible to disease, the whole plant usually loses and dies. On the cutting bed, wet rot occurs from the healing and forming area of the cuttings, which can also cause serious root neck rot.

[pathogen] the pathogen is a fungus, Sclerotium rolfsii, sclerotia epiphyte, 0.5 ml 1.0 mm in diameter, smooth and shiny, shaped like rapeseed.

[incidence regularity] the pathogen has a wide host range, which can harm dozens of plants, such as cactus, orchid, squirrel tail, melon leaf chrysanthemum, chrysanthemum, goldfish grass, Persian chrysanthemum, marble chrysanthemum, iris, tulip, hyacinth, lily, Hosta and so on. The pathogen exists as mycelia or sclerotia residues in diseased bodies, diseased plants, wild plants and soil. Shade nuclei can survive in soil for 3-4 years, but the survival time in water and wet soil is very short. High humidity is beneficial to the spread of bacteria, and the disease occurs in summer.

[prevention and control methods]

(1) Horticultural control: avoid continuous cropping with susceptible plants; the base fertilizer should be fully mature to avoid carrying bacteria; proper ventilation to avoid planting too dense.

(2) Pesticide control: disinfect the soil before planting (see Orchid White Silk Disease), or use 50% bacillus, 5 grams per square meter. When the disease occurs during the growing period, the diseased plants should be dug out in time, and the diseased points should be disinfected with lime, or irrigated with 65% Dysen zinc 600% 800 times, or other fungicides. It can also be sprayed or irrigated with 1000 times of EC to control carnation white silk disease.

Carnation white silk disease

Shanghai, Hangzhou.

[symptoms] the disease occurs at the base of the stem near the soil surface and turns brown and rotten; the diseased stem tissue is cut and tea-brown or dark-brown rot develops to the center from the outside; the xylem also changes color upward, and the pinnately radiating white hyphae can spread to the surrounding soil surface; then sclerotia the size of initially white and later yellowish-brown rapeseed is formed on the diseased part and surrounding soil surface mycelia. After the plant is susceptible to disease, the whole plant usually loses and dies. On the cutting bed, wet rot occurs from the healing and forming area of the cuttings, which can also cause serious root neck rot.

[pathogen] the pathogen is a fungus, Sclerotium rolfsii, sclerotia epiphyte, 0.5 ml 1.0 mm in diameter, smooth and shiny, shaped like rapeseed.

[incidence regularity] the pathogen has a wide host range, which can harm dozens of plants, such as cactus, orchid, squirrel tail, melon leaf chrysanthemum, chrysanthemum, goldfish grass, Persian chrysanthemum, marble chrysanthemum, iris, tulip, hyacinth, lily, Hosta and so on. The pathogen exists as mycelia or sclerotia residues in diseased bodies, diseased plants, wild plants and soil. Shade nuclei can survive in soil for 3-4 years, but the survival time in water and wet soil is very short. High humidity is beneficial to the spread of bacteria, and the disease occurs in summer.

[prevention and control methods]

(1) Horticultural control: avoid continuous cropping with susceptible plants; the base fertilizer should be fully mature to avoid carrying bacteria; proper ventilation to avoid planting too dense.

(2) Pesticide control: disinfect the soil before planting (see Orchid White Silk Disease), or use 50% bacillus, 5 grams per square meter. When the disease occurs during the growing period, the diseased plants should be dug out in time, and the diseased points should be disinfected with lime, or irrigated with 65% Dysen zinc 600% 800 times, or other fungicides. It can also be sprayed or irrigated with 1000 times of 20% EC to control carnation white silk disease.