Sclerotinia sclerotinia sclerotinia is a bacterial disease that grows on radish, how to prevent and

In the early stage of sclerotinia disease, stains appear on the surface of fleshy roots, and with the prolongation of the disease, the spots expand into irregular, watery, brown spots. The lesions mostly appear in the upper half of the fleshy roots and extend upwards to the base of the petiole, making the base of the petiole brown and withered. When the air humidity is high, dirty white spider filament mycelium appears on the lesions, and the lesions soften and decay.

Carrots get sick during the growing season, and the fleshy roots of the plant are damaged. Water stains appear on the top or sunny side, and later turn brown wet rot with a slight depression. White hyphae grow on the surface of the lesions, and irregular sclerotia are formed in the later stage, and then the fleshy roots soften and rot.

In a humid environment, white cotton mycelium and sclerotia of rat feces appeared on the surface of fleshy roots. Sclerotinia sclerotinia sclerotiorum will continue to occur during storage, leading to rotting of the cellar.

Sclerotinia sclerotinia carrot is a soil-borne disease with mycelium as the main source of infection, and the onset temperature is 20. When the environmental conditions are suitable, the sclerotia germinates to produce ascomycetes, and the ascospores emitted by the ascomycetes are propagated by airflow and directly invade the stratum corneum of the host's epidermis, causing primary infection. The following spring, many of the infections were caused by wind and rain or the contact friction of diseased healthy plants, causing serious harm.

Diseased plants and fruits in sheds after soft rot and contact with healthy parts of the plant can also cause disease and become another route of reinfection. In addition, high planting densities can easily lead to sclerotinia sclerotinia disease.

Sclerotinia carrotirum, a genus of ascomycetes. Sclerotinia sclerotinia sclerotinia is mainly manifested by a large number of gray spots on the surface of leaves. Sclerotinia sclerotinia sclerotinia usually occurs in the field and mainly damages the fleshy roots of carrots, causing rot of the rhizomes of carrot plants, softening the underground fleshy roots of carrots, and producing white cotton-like hyphae and black sclerotia outside the sclerotinia sclerotinia sites.

Sclerotinia sclerotiorum is mainly safely overwintered in soil or seeds with hyphae, sclerotia, and ascospores. Sclerotinia sclerotinia sclerotinia is mainly caused by hyphae as the main source of infection, and reinfection is constituted by contact with diseased healthy plants. The hyphae of carrot sclerotinia sclerotinia can grow from 0-35, and the optimal temperature for hyphal growth and sclerotia formation is 20, and the maximum growth temperature is 35.

Sclerotinia sclerotinia is usually caused by low temperature and high humidity. Sclerotinia sclerotinia mainly affects stem bases and petioles. Most of the lesions of sclerotinia sclerotinia rot in brown water stains.

When the humidity is high, the white mycelium and sclerotia are densely distributed on the surface of the diseased area, and the sclerotia are white at first, and then gradually turn into black rat droppings.

Sclerotinia sclerotiorum is caused by airborne conidia that live on flowers and senescent leaves and come into contact with healthy plants. The disease requires high moisture and temperature, and low temperature, high humidity or heavy rain in early spring or late autumn are conducive to the occurrence and epidemic of the disease, and the sclerotia form time is short and the number is large. The disease is more severe in fields where cucurbitaceae, solanaceae and cruciferous vegetables are grown, in poorly drained low-lying areas or in cases of partial nitrogen fertilization, frost and frost damage.

In the hard-hit areas or hard-hit areas and grasses planted for more than 3 years, the soil should be flooded to kill the sterilization nucleus. The utensils used to transport the carrots should be sterilized, and the diseased fleshy roots should be removed before they can be put into the cellar. The cellar temperature is controlled at 13, and the relative humidity is about 80% to prevent the dripping water from freezing on the top of the cellar.

1) Reasonable crop rotation, deep ploughing, drying, strengthen fertilizer and water management, timely removal of weeds and diseased plants, and reduce the source of disease in the field. Disinfect storage pits or other types of storage sites with chemicals to control storage temperature and humidity.

Before sowing, radish should be selected with 10% 14% salt water to make the sclerotia and other impurities float and be removed, and then sow after rinsing with water; Radish rotation is implemented, and crops that are easily infected by sclerotinia are best not to be cropped continuously, and at the same time, high furrow planting is used, timely drainage after rain, reducing soil and air humidity, avoiding partial application of nitrogen fertilizer, etc.

Pesticides. Because after my radish is sprayed with pesticides, it is not allowed to have sclerotinia disease, so it should be controlled by pesticides.

Cucumber cultivation in protected areas, susceptible to cucumber sclerotinia disease, the disease is a soil-borne virus, mainly transmitted through the soil, cucumber seedlings, seedlings can be diseased, cucumber is infected, rotten fruit will occur, serious will make seedlings die, pathogenic bacteria mainly in the form of sclerotia follow the disease residue in the soil winter, will also spread with the seed, when the environment is suitable, sclerotia will germinate and spread. The prevention and control of sclerotinia sclerotinia in cucumber is very difficult, and comprehensive control measures must be implemented.

Planting cucumbers in the open field is a traditional planting method, after the demand for the market increases, there is a pattern of facility planting one after another, which fills the gap of the lack of market quality, solves the situation that cucumbers cannot be planted in all seasons due to the influence of the weather, and also fills the vacancy of winter cucumbers.

<> the economic loss caused by replanting and re-seedling can reach 15%-25% of the entire planting cost, and the conservative loss of this disease can reach 70%-85% at the mature plant stage (including the fruit setting stage), which can lead to a reduction of about 60% or the risk of no harvest in this round of planting products. Cucumber sclerotinia has a wide range of hosts, in addition to harming cucumbers, it can also harm tomatoes, sweet (spicy) peppers, eggplants, peas, potatoes, carrots, celery and a variety of cross-tracking flowers.

After the cucumber is harvested, the plants in the field should be cleaned up, and the diseased residues can not be left in the field, and the soil can be turned deeply, the depth of 20 25 cm can effectively control the formation of ascomycetes. Taking advantage of the summer slack time, fill the planting plot with water, cover it with black film, and let the high temperature be exposed to the sun for 15 to 20 days. Deep ploughing can change soil properties, promote microbial activities, accelerate the decomposition of organic matter, facilitate the development of plant roots, exchange between upper and lower soil, and reduce the breeding rate of pathogens.

The humidity in the field is relatively high, or the infection occurs in rainy weather, and the disease is fastest at 15 degrees, and it can spread with the help of wind.

The temperature range of Sclerotinia sclerotinia is 0 30, and the optimal temperature is about 20. The mycelium is not tolerant to dryness, and develops well when the relative humidity of the air is above 80%, and the development is inhibited when it is less than 70%. The pathogen mainly leaves sclerotia in the soil or mixed with seeds for summer or winter, and germinates in a suitable environment, and the resulting sporangia are born on the sporangia disk.

The spores are transmitted by air currents, which is conducive to the disease in the case of poor drainage, poor ventilation, and partial application of nitrogen fertilizer.

If the planted radish fungus has this disease, it is because the environmental temperature control is not very good, so it will lead to the appearance of this disease, and the temperature in the greenhouse should be adjusted again, and then observed. In addition to this, you should also pay attention to the amount of moisture.

This is because there are a lot of bugs in the radish, and these bugs will develop nuclear disease when they eat the roots.

<> prevention and control methods: reasonable crop rotation, deep ploughing, drying, strengthening fertilizer and water management, timely removal of weeds, diseased and disabled plants, and reducing the source of disease in the field. Disinfect the storage cellar or other types of storage sites to control the storage temperature and humidity.

15 kg of sulphur and 150 225 kg of lime were sprayed at the beginning of the disease; During storage, it can be sprayed with 1000 times of 50% iprodione wettable powder or 1500 times of 50% pythium wettable powder, or 50 grams of fumigation per 100 meters of thiaphanate.

Agricultural prevention and control: select disease-resistant varieties, cultivate age-appropriate strong seedlings, remove disease residues in time after harvest and carry out deep turning.

Pharmaceutical prevention and control: as a disease prevention or in the early stage of the disease, you can choose 430 grams of tebuconazole suspension (Haolik) 1500 2000 times, or 400 grams of pyrimycomine suspension (Shijiale) 600 1200 times liquid, or 50% acimimidol water dispersible granules (Kaiser) 1000 1500 times liquid and other agents can be sprayed evenly, once every 7 10 days, 2 3 times in a row. Pay attention to the rotation of the agent.