Control methods of Sclerotinia sclerotiorum

[symptom] damage to leaves and bulbs is a common disease of hyacinth. The growth of the infected plants was blocked and the growth was retarded. The leaves of the diseased plants were grayish yellow, and with the development of the disease, the leaves gradually withered and easily detached from the bulb; the interior of the susceptible bulb changed color and rotted to varying degrees, producing white hyphae inside, and a flattened sclerotia could be seen between the bulb and the scale. it was white at first and gradually turned dark brown.

[pathogen and pathogenesis] is a fungal disease, the pathogen is Sclerotinia fungi, overwintering with sclerotia in the soil, the pathogenic hyphae spread in the soil and infect the surrounding plants.

[prevention and control methods]

1. When diseased plants are found, the diseased leaves, buds and bulbs should be removed as soon as possible.

2. The fine soil mixed with pentachloronitrobenzene can be used as poisonous soil and scattered around the plant.

Prevention and control of white silk disease of hyacinth

[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. Disinfect the soil before ② planting, or use 50% methamphetamine, 59 per square meter. 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. Each plant (hole) was irrigated with 0.4 × 0.5L. 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.

Control methods of Sclerotinia sclerotiorum

Sclerotinia sclerotiorum is a common disease of vanilla.

Symptoms the leaves of Cymbidium turned yellowish after being injured, the plant growth stagnated, and then the leaves withered and fell off easily. The inside of the bulb changed color and gradually rotted. Long and flat sclerotia can be found between the scales. The sclerotia is white at first and becomes black later. The sclerotia is about 12 mm wide.

Sclerotinia sclerotiorum Sclerotiniabulborum (Wakk.) Rehm. It belongs to the subphylum ascomycetes. The pathogen overwinters in the soil with sclerotia, and the fungal cord formed can pass through the soil to infect the host. Ascospores produced in spring can also cause harm. This fungus attacks hyacinth, cotton jujube and saffron.

Prevention and cure method

1. Pay attention to check the diseased bulbs and burn them together with the exfoliated leaves.

2. The contaminated soil can be sterilized by heating or by medicine.

3. When planting bulbs, spread 70% pentachloronitrobenzene around the bulbs, and then cover the soil. At the time of onset, 20% methyl rifampicin EC was sprayed with 1000 times solution and 50% nonglidine 1000 times solution. 10% smoke agent can be used in the shed.