Mustard black spot disease often appears, how does mustard black spot occur?

This disease is usually caused by too much rain or too low temperature. There is also the influence of the weather, it is very likely that continuous rainy days will lead to the occurrence of these black spots.

Black spot is also known as black mold, the main damage is Chinese cabbage, mustard greens, cabbage, pineapple and other cruciferous vegetables, the disease is a fungal disease, the fungus overwinters on the residue of the diseased plant and seeds with mycelium and conidia, and after the right temperature comes, they grow, thus forming black mold.

I was infected with some bacteria, and I didn't get medical treatment in time, and I didn't have ventilation, so I got this disease.

Mustard black spot disease is generally from the beginning of the mustard leaf disease, the disease spot is round, generally brown or dark brown, the occurrence of mustard black spot disease will seriously affect the growth and quality of mustard, so we need to know how to prevent and control, the following China pesticide first network will explain to youHow to prevent and treat mustard black spot

The main reasons for the occurrence of mustard black spot disease are early sowing, high density, lack of water and fertilizer, poor plant growth, and weak disease resistance

Disease-resistant varieties are selected.

Xiaomussel, Qingqing, Beijing Xin No. 1, Beijing Xin No. 5, Beijing 88, Zhengza No. 2, Luoyang Tokyo No. 3, Zhengbai No. 4, Jinqing No. 9, Jincai No. 3, Shuangqing 156, Shuangqing and other more disease-resistant varieties were selected.

Seed disinfection Leave the seeds from disease-free seeds, or soak the infected seeds in 50 warm water for 25 minutes, then immediately move them into cold water, and then remove the seeds to dry and sow seeds. It can also be mixed with 50% of the seed weight of the seed with the wettable powder, or with 50% of the weight of the seed with the double wettable powder of the seeds.

Strengthen management and implement crop rotation.

Implement a 2-year crop rotation with non-cruciferous vegetables, and at the same time arrange stubble, the Chinese cabbage field should be kept as far away as possible from the cruciferous vegetable field. Apply plantar fertilizer, but to apply well-rotted high-quality organic fertilizer, and increase phosphorus, potassium fertilizer, where conditions permit, can also use formula fertilization, so that the plant grows well, can improve the disease resistance of the plant. Diseased leaves and sick remnants should be removed from the field in a timely manner, buried or burned.

Pharmaceutical prevention and control. In the early stage of the disease, you can use 1000 times of 50% promethane wettable powder, or 800 times of 50% chlormexin wettable powder, or 50% Fumei double wettable powder 500 times, or 40% sterilized Dan wettable powder 400 times, or 64% alum wettable powder 500 times, or 50% Suclin wettable powder 1000 times, or 70% mancozeb wettable powder 400 times and other agents, spray 1 time every 7 days, spray 3 4 times.

Mustard leukoplakia is very common, what are the symptoms of mustard leukoplakia? There are two reasons why mustard greens have white rust, one is the problem of fertilization, and the other is the problem of light. In the growth process of mustard, if it is found that mustard has signs of disease, it should be pulled out in time to avoid passing ten or ten hundreds, so how can it be seen that mustard has anthracnose?

The disease mainly affects the leaves, petioles and midribs, and sometimes the peduncle area. The main feature of the disease is small pale spots, which then enlarge into grayish-brown sunken round spots.

It is not easy to identify the diseases on crops accurately, and in field practice, not only professional and systematic theoretical knowledge is required, but also long-term control experience in the field. Just like the anthrax of mustard greens, there are many that do plant protection, damage the leaves, and also damage the petioles and veins. Leaves are initially grayish-brown or grayish-white with small nearly round spots, margins distinct, mm in diameter.

It then expands to light gray to white amorphous lesions ranging from 6 to 18 mm, with pale green halos on the periphery or moist edges of the lesions.

It is a white bacterial film, and a thick yellow-white film will float on the water surface during the pickling process, which is the normal manifestation of fermentation, and it is also the manifestation that the pickled vegetables contain active probiotics. It doesn't take long to leave it, just rinse it. This powdery white color is the sporangia.

Generally, shepherd's cabbage is infected by soil or air fungi, and then grows small spores, and after it breaks, there are lumps of white powder, which are the white spots you see. (There could also be aphids.)

On weekend mornings, I rode to the bottom of the hillside of any field on the outskirts of the city, and looked at the small green plants in a yellow land, which were basically purses, and it was a big bag after a short time, and I gave them to relatives and friends after I came back, exercised my body, and enriched my life. This is caused by a fungus of a subphylum Flagellate. White vesicles grow on the foliage, and when the vesicles rupture, they scatter white powder, which is the sporangia of the pathogenic bacteria.

Prevention and control methods: If the disease and residue are not removed in time, they should be buried or burned in depth to reduce the source of primary infection.

The pathogen mainly overwinters with mycelium and mycelium left on the ground with the diseased residues, and can also overwinter with conidia adhering to the surface of seeds. It spreads through rainwater or irrigation water sputtering, and is invaded by stomata. The pathogen likes a warm and humid environment, and the suitable temperature for the onset of the disease is 11 23, and the relative humidity is required to be more than 60%.

Sowing too early, continuous cropping plots or plots with insufficient fertilizer are prone to disease.

The main reason is actually that it has been exposed to some sunlight for a long time, and then it has caused such a disease, and there are some bacteria in this soil, so it will cause such a disease, which is very terrible.

The first of mustard leukoplakia is the vitiligo virus, which causes the mustard leaves to turn white, appear white spots, and reduce the yield.

This disease is more common in autumn and is generally caused by fungal infection, which can be prevented and treated with carbendazim.

In amaranth cultivation, brown spot pathogens mainly damage amaranth leaves. After the leaves of amaranth are infected by brown spot pathogens, round or irregular brown spots with a size of 2 4 mm will appear in the early stage, and the diseased leaves will be gray-brown or white in the later stage, and the diseased leaves will have obvious contrast with the healthy parts. There are many small black spots on the leaf surface and dorsal surface of the leaf, which are conidia.

The brown spot fungus attaches to the residual tissues of diseased plants through hyphae or conidia. If these diseased plants are left in the ground, the pathogen will lurk in the ground to survive the winter safely.

Under suitable environmental conditions, latent bacteria will germinate conidia and spread to amaranth plants through air currents or rainwater, and bacteria will invade the internal tissues and cells of the host plant from the epidermis, resulting in the first infection of cultivated amaranth with brown spot disease. In infected amaranth, the affected area will be divided into several generations of conidia, which are also transmitted by air currents or rainwater, and the planted amaranth is cross-infected many times, resulting in severe amaranth disease. The main outbreak of amaranth brown spot is from May to September. Summer and autumn are rainy and the weather is hot and sultry, which is more likely to cause disease; Amaranth is planted in continuous cropping, and the planting area is low-lying.

In case of rainfall, the rainwater is not drained in time, the onset of the disease is early, and the disease is more serious after the onset of the disease; Cultivated amaranth is planted too densely, with poor ventilation and light, and nitrogen fertilizer can lead to aggravation of the disease.

Brown spot prefers hot and humid environments. Amaranth can be infected with the disease from the ripening stage to the harvest stage, and the incubation period of the pathogen is about 3 5 days, and it can cause disease in the temperature environment of 15 35 years. The incidence is highest when the relative humidity of the air reaches 90% between 25 and 32.

In case of heavy rain or open air, the disease occurs quickly and spreads quickly. Sow seeds at the right time. In areas with severe brown spot disease, sowing should be avoided in the rainy season as much as possible, and sowing should be postponed appropriately.

On-site management. Do not plant too dense amaranth when sowing or planting, so that there are good ventilation and lighting conditions between plants; When fertilizing, nitrogen fertilizer is not applied, and phosphorus and potassium fertilizer are appropriately increased to improve plant disease resistance; Before the rainy season, dredge the drainage channels in the field to prevent diseases caused by excessive water accumulation and high humidity in the field after the rain.

Amaranth should be harvested in time. After harvesting, the sick and disabled people left in the field should be cleaned up in time, and taken out of the field for burning or deep burial; At the same time, the soil in the field is deeply tilled, which can accelerate the decay and decomposition of amaranth residue left in the field, and play a role in inhibiting the growth of pathogens. Pesticide control.

In the early stage of amaranth brown spot disease, in order to prevent the spread of the disease, the following pesticides should be sprayed, once every 8 days, and 2 or 3 times in a row. High-efficiency, low-toxicity, low-residue prevention and control drugs: difenoconazole, tebuconazole suspension and other sprays can be selected.

During the prevention and control of amaranth brown spot disease, the specific application multiples of pesticides used must be strictly determined according to the degree of damage of crop diseases and the instructions for the use of various pesticide varieties.

It is mainly harmful to leaves. The leaf lesions are round to amorphous, yellow-brown, and fade to gray-brown to gray-white in the middle of the posterior diseased class, and the boundaries of the diseased and healthy parts are clear, and dense small black spots can be seen on both sides of the lesions. i.e. pathogenic bacterium conidia,

When the temperature and humidity conditions of amaranth black spot disease are suitable, the pathogen can complete the invasion in more than ten hours, and the disease will develop after 5-7 days of incubation period, and the disease will spread quickly in the field. Pathogens 10-33 can develop, the optimal temperature for development is 18-23, and the relative humidity of more than 85% is required. Therefore, when there is high humidity, heavy rain, and mild temperature, it is easy to develop the disease.

It is the yellowing of the leaves and the rotting of the roots, which leads to a decrease in yields and serious losses to farmers.

In this case, yellow spots will appear on the edges of the leaves, and the leaves will then form a dry rot, and the stems may also rot and fall off.

After being damaged, it must start at the edge of the leaves, slowly decay, and there will be brown diseases, and finally the neck, causing the plant to dry up.

While avoiding stubble, it is also necessary to do a good job of drainage ditches in the vegetable garden, which can also reduce germs**. In the early stage of amaranth brown spot disease, spray many agents such as carbendazim 800 times or zinc 800-1000 times in time. At the beginning of the disease, the diseased leaves should be removed in time and brought to the vegetable garden for unified treatment, so as to reduce the germs**.

Chemical weeding has the best and most suitable control effect in peanut 1 3 compound leaves (three leaves on one petiole is counted as one compound leaf) and weeds 2 5 leaf stages. With the increase of weed resistance, we should not choose a single herbicide, but at least choose 2-3 herbicides for compound use to achieve better results. Continuous stubble planting amaranth, the planting ground is low-lying terrain, in case of rainfall, when the rainwater drainage is not timely, it will induce disease earlier, and the disease will be more serious after the onset; If the cultivated amaranth is too densely planted, its ventilation and light properties are poor, and nitrogen fertilizer is applied too much, which will lead to aggravation of the disease.

When cultivating amaranth, it is necessary to sow it at the appropriate sowing time; The basal fertilizer needs to be applied sufficiently, and the basal fertilizer should be mainly farmhouse fertilizer, with no partial application of nitrogen fertilizer, and appropriate application of phosphorus and potassium fertilizer to cultivate strong seedlings to resist diseases; In agricultural operations, it is best to rinse hands and farm tools that have been in contact with diseased plants with soapy water to prevent the plants from being infected with diseases after contact. In addition, the high planting density and low-lying terrain of amaranth are conducive to the disease. At the same time, growers need to pay attention to the possibility of advanced occurrence of amaranth continuous cropping and the degree of damage is relatively serious, and the implementation of crop rotation can effectively reduce the pathogen.

Seed treatment should be carried out with disease-free plants or seed treatment before sowing, that is, seed dressing with seed quality of 25% methafen wettable powder, or seed dressing with seed quality of 72% manganese-zinc-frosturea wettable powder or 69% manganese-zinc-enyl wettable powder. After the harvest of the previous stubble, remove the residual branches and leaves in time. Strengthen fertilizer and water management, reasonable dense planting, avoid partial application of nitrogen fertilizer, and increase the application of phosphorus and potassium fertilizer.

Water water frequently, correctly grasp the reasonable field humidity, drain water in time after rain, reduce humidity and inhibit bacteria. If the diseased plant is found, it should be removed in time and disposed of reasonably.

Pesticides. Because after my amaranth got brown spot, it would be good to use some pesticides, so I should use pesticides to prevent it.

Choose high-quality and disease-resistant seeds, pay attention to sowing in turns, and apply fertilizer and watering in time.

Amaranth brown spot is a bacterial disease, mainly for the damage to leaves, so in the planting should pay attention to ventilation, moisture drainage, at the onset of the disease, the choice of agricultural streptomycin sulfate soluble powder or can kill wettable powder and other agents, spray once every 7 10 days, spray 2 3 times in a row.

Amaranth brown spot disease is extremely harmful, and the symptoms of brown spot are: Its leaf lesions are yellow-brown round, and the middle of the disease class will fade to gray-brown or gray-white, and the boundary of the diseased part is very clear, and some small black spots can be seen on both sides of the lesions.

Fungal disease, the lower leaves begin to disease, gradually spread to the upper part, the initial round or oval, purple-brown, later black, diameter of 5-10mm, the boundary is clear, severe lesions can be connected into a piece, so that the leaves yellow and fall off, affect flowering.

Mainly harms the leaves. The leaf lesions are round to amorphous, yellow-brown, and the middle part of the lesions fades to gray-brown to gray-white in the later stage, and the boundaries of the diseased and healthy parts are clear, and dense small black spots can be seen on both sides of the lesions. i.e. pathogenic bacterium conidia,

For the prevention and control of pesticides, 58% methyl manganese zinc wettable powder 500 times liquid, 80% Dasheng wettable powder 800 times liquid, 40% sterilized Dan wettable powder 400 times liquid, 40% gramsan wettable powder 500 times liquid, 50% Lide wettable powder 500 times liquid.

1.Leveling the land of appropriate density, sowing in time, and harvesting in time.

2.Apply sufficient amount of organic fertilizer and top dressing in a timely manner. Then apply fast-acting fertilizer, nitrogen, phosphorus and potassium fertilizer together. Scientific irrigation, pay attention to drainage after rain.

3.Rotation with non-host crops for more than 2 years in endemic areas.

4.Remove diseased plants from the field in time. After harvesting, the fields are thoroughly removed from the fields and the soil is dug deeply.

5.Chemical control, in the early stage of the disease, 500 times 58% methalene-zinc wettable powder should be sprayed in time.