Mustard downy mildew is a common disease, what is the harm of mustard downy mildew?

At the beginning of the disease, the leaf surface produces pale green dots and develops into pale yellow lesions, which later expand into irregular lesions, and the dorsal lesions of the leaves are covered with a white mold layer. The lesions spread upwards from the lower part of the plant and are prone to disease at night when there is dew. Diseased leaves wither yellow when drought, diseased leaves rot when wet, under the right temperature and humidity, it only takes 2 3 days for the pathogen to invade the disease, after the onset of spinach, the damaged part will breed downy mildew sporangia, the sporangia spread with the help of airflow, rainwater, insects, farming, etc., causing spinach to be infected with downy mildew fungus many times, <>

Under the right temperature and humidity, it only takes 2 or 3 days for the germ to invade the disease, after the onset of spinach, the damaged part will breed downy mildew sporangia, and the sporangia will spread with the help of airflow, rainwater, insects, farming, etc., causing spinach to be infected with downy mildew fungus many times. The cultivation of protected areas such as greenhouse plastic greenhouses should pay attention to ventilation and light transmission, cooling and humidity drainage, deep turning of the land, application of sufficient base fertilizer, and increase the application of phosphorus and potassium fertilizer!

If it is found that the diseased plants infected by downy mildew fungus are uprooted in time, they should be taken out of the field to burn or buried deeply, and at the same time, quicklime should be sprinkled to treat the planting holes to prevent the spread of the source of disease. At harvest time, the leaves of the residual plants are completely removed and taken out of the field to be buried or burned. The most suitable temperature for downy mildew is 15-17 degrees Celsius, which is spread by air movement, field tillage, watering and insects.

When the density of plants in the field is large, the air humidity is high, and the temperature is suitable, the onset of the disease is rapid.

70% ethylphosphine aluminum. 400 times of manganese-zinc wettable powder; 58% Methyl Frost. manganese-zinc wettable powder 500 times liquid; Downy mildew hydrochloride (Pulik) water solution 800 times liquid or 75% chlorothalonil wettable powder 600 times liquid spray, spray once every 7 10 days or so, continuous control 2 3 times.

Sowing: 50 100 grams of Trichoderma harzianum per 50 kg of seeds, seedling mixing substrate soil: 100 grams of Trichoderma harzianum per cube, seedbed spraying:

1 cubic with 5 grams of Trichoderma harzianum, spray once every 5 to 7 days. It can prevent the occurrence of diseases.

The main manifestation of mustard mildew downy disease is that the leaves of mustard greens will turn yellow, with large and small mold spots. This causes the entire plant to rot. The harm is very great.

Its leaves are a little yellowish, some signs of wilting, the roots are rotten, the leaves are prone to many spots, and the leaves will slowly change from round to polygonal.

The danger of this disease is that the mustard will grow very small, and the leaves also have brown, black spots on the leaves, the leaves will turn yellow, and the yield will decrease.

The disease causes mold to develop on the leaves, which then spreads to the entire plant and eventually kills the plant.

We should spray mustard greens with pesticides to prevent pests and diseases, and we should spray some vinegar so that there will be good control.

For the pest control of mustard greens, you can spray with 75% chlorothalonil (500 times the solution) or 58% methamalene manganese zinc (500 times the solution), spray once every 7-10 days, and spray 2-3 times continuously. Pest control (taking cabbage worm as an example): spray with 10% cypermethrin emulsifiable concentrate (2000-3000 times liquid) and other drugs, and protect the seedbed with a screen to prevent adults from laying eggs on seedlings.

You can buy some medicines, which can get rid of these pests without causing any impact on the vegetables, which can be well controlled.

At the beginning of downy mildew, the leaves have pale green spots, with the development of the disease, they change from yellow-green to yellow-brown or light brown, the lesions are polygonal after expansion, and purple-gray mildew will be produced on the leaf back lesions when wet, and the lesions will soon wither when the disease is dry at high temperature, and the leaves have pale green spots, and with the development of the disease, they change from yellow-green to yellow-brown or light brown, and the lesions are polygonal after expansion, and purple-gray mildew will be produced on the leaf dorsal lesions when wet. When the heat is dry, the lesions will quickly turn yellow.

Downy mildew is a fungal disease, caused by false downy mildew infiltration, its occurrence conditions are that there are water droplets or water film on the leaves to germinate, rainy and humid environment is conducive to the germination and invasion of downy mildew fungus, and the disease is serious, even rainy or foggy weather, the disease will spread rapidly and mainly harm the leaves. In the early stage of leaf disease, the lesions are pale green dots, which are not obvious at the margins, and are completely irregular in shape after enlargement. A grayish-white mold layer is produced on the lesions on the dorsal leaves of the leaves, which then turns grayish-purple and spreads upwards from the lower part of the plant.

In the early stage of the disease, 25 Rui poison mold 600 times liquid or 58 methalene manganese zinc 500 times liquid, 40 50 kg of medicinal solution per mu, sprayed once every 7 10 days. 2. Dead leaves caused by gray mold When the disease occurs, fertilizer and water management should be developed from the tip of the leaf downward: broccoli should not be watered too much, otherwise the humidity in the greenhouse will be too large, causing the plant to be susceptible to disease and rotten balls.

The general principle is to water once every 10 days or so, and after watering, the cultivator adjusts the soil temperature and humidity to promote the growth of plant roots. Broccoli should be topdressed 2 times from planting to harvesting.

Every year in spring, our family is the first to sow green vegetables, because as long as the temperature of the seedlings is guaranteed, the green vegetables are time-saving and labor-saving during the growth period, and they are easy to manage. Let's first find a piece of loose soil idle land, sprinkle organic fertilizer first, water the bottom of the foot downy mildew is from the seedling to the adult stage can occur pathogens, to the adult stage of the most serious disease, mainly harm the leaves, the early stage of the disease, the leaves will appear yellow-brown lesions.

The leaves are bilateral, yellowish-green or gradually turning yellow, and due to the restriction of the leaf veins, they expand from nearly round to polygonal, with a diameter of 3 12 mm. When the humidity is high, a white mold layer grows on the back of the leaves, that is, the sporangia and sporangia of pathogenic bacteria, and the leaves dry up severely, affecting the yield and quality.

The main symptom is the damage to the leaves, the color of the lesions on the leaves will change from yellow-green to yellow, due to the restriction of the leaf veins, the shape of the lesions expands from round to polygonal, the mustard moisture is too large, and the white mold layer grows on the back of the lesions. In severe cases, the lesions are patchy, and the leaves turn yellow and dry.

In fact, in our real life, we will meet all kinds of people every day, and at the same time, we will encounter all kinds of things, and in the midst of these things, we may have a new impact to believe that everyone has also seen the fact that celery frost poison is a disease on the Internet. Therefore, many people will have questions, that is, how to prevent celery frost poison disease? on this issue.

For example, you can choose the kind of disease-resistant varieties, and at the same time, you should also have a reasonable crop rotation, let's learn about it in detail.

1. Choose disease-resistant varieties

With the rapid development of science and technology, there are now many kinds of the same plant, and its species can also be selected by us. Especially for this kind of celery, we all know that celery is not accounted for, and it is also very popular in real life, so many people are now planting in a large area, but sometimes there will be the status quo of this double poison disease. For such a condition, I think it is okay to use that one.

Disease-resistant varieties, because this variety itself can be disease-resistant, do not need us to use pesticides.

2. Reasonable crop rotation

If we plant the same crops every year, then it may cause a lot of nutrients in the soil to be absorbed, so I think it can be a reasonable rotation, for example, it can be sown every few years, or after a period of time, so that he can make the nutrients in the land reasonably absorbed.

Therefore, we should also pay more attention to this aspect of the problem in our daily life, for everyone, in the process of planting, it is likely that there will be a situation that we have never encountered, at this time we can ask those who are more experienced, and learn certain lessons from them, so that we can avoid detours. The above is some of the understandings I have summarized, and I hope it can be used by everyone.

This disease is caused by infection with fungi and can be prevented with carbendazim, which is generally effective after two sprays.

Mustard downy mildew is a disease, mustard downy mildew should be prevented and controlled in this way: varieties should be selected disease-resistant varieties, seed disinfection and sowing with 50% of the seed weight of the Fumei or 25% Ruixin fungus to eliminate the germs on the seed surface, field management seedling stage in fact, to remove diseased seedlings and weak seedlings.

If you want to prevent and control downy mildew of mustard, you can spray relevant drugs before the onset of the disease, which has the best effect and can also play a certain role.

Pesticides. Because my mustard greens are sprayed with pesticides, downy mildew disappears, so pesticides should be used to prevent it.

Downy mildew occurs when the temperature is 25-30 degrees Celsius, the soil moisture is sufficient, especially in the morning and evening there is dew. Therefore, the prevention and control of downy mildew is to control the amount of watering. Lettuce watering should be watered frequently with small water, not flooded with large water.

Second, reasonable dense planting, keep the field ventilated and breathable, and reduce humidity. 3. Chemical prevention and control. Downy mildew is generally caused by fungi, fungicides should be used, better fungicides are chlorobromoisocyanuric acid, enoylmorpholine, mancozeb, etc., which can be mixed with frost urea cyanide (downy mildew hydrochloride, methamethyl, refined methamethyl) and enoylmorpholine (occultamine isooctyl ester, fluopyramide, fluridinamide).

You can choose 25% etherstrobin suspension 1500 times, or 69% enoylmorpholine-manganese-zinc wettable powder 800-1000 times, or 72% dew wettable powder 600-800 times, or Pulik liquid 600 times, or 72% gfrosty cyanide wettable powder 600-800 times, the symptom is that the whole leaf or even the whole lettuce is rotted and becomes transparent, and exudes a very smelly smell. The cause of soft rot is mostly caused by the plant being accidentally broken or the leaves are damaged, and the germs enter the plant along the wound, causing it to become infected and rot.

Lettuce leaves appear pale yellow near-round lesions from the basal leaf upwards, and a white frosty mold layer grows on the back of the leaf when the air is humid, sometimes on the front of the leaf. When the white mold layer is severe and the lesions are fused with each other, the leaves will turn yellow and die. At this time, downy mildew has reached its peak outbreak.

The source of the disease is latent in the soil and the diseased plants for overwintering, and the damaged plants invade directly from the wound. Therefore, we should be careful not to injure the seedlings to avoid the occurrence of pests and diseases. It is necessary to pay attention to drainage and flood prevention, find that the diseased plants are removed in time, and if the weather is good, use the sun to sterilize and disinfect the deep plots.

Botrytis sclerotinia and anthracnose, bacterial diseases of brown rot. In the middle of the period aphids, cabbage worms, Spodoptera litura. To prevent the initial bacteria, 2% didimethylmycin and 40% polysulfur suspension 400 times liquid spray.

Pests are sprayed with 70% chloroline powder and cypermethrin spray.

Downy mildew mainly harms the leaves, and the front of the leaf appears grayish-white, pale yellow or yellow-green with inconspicuous periphery in the early stage of the disease, and then expands into yellow-brown lesions, which are polygonal or irregular due to the restriction of leaf veins, and the back of the leaves is densely covered with white frosty mold. When there are many diseased spots, they are connected to each other, so that the diseased leaves die locally or the whole leaf. Diseased plants tend to dry up layer by layer from the outside to the inside, and in severe cases, only a small heart leaf ball remains.

It is very contagious, and it can also damage plants, and at the same time, it will also cause deformities in plants, and it will also cause a lot of plant production and plant death.

As a result, there are spots on the leaves, and the leaves will turn yellow, will fall, and will also reduce the yield a lot, which will cause a lot of bacteria in the soil.

Botrytis cineris is characterized by the formation of a gray mold layer under wet conditions. Botrytis is extremely harmful and can infect almost every flower, causing huge losses. Botrytis mainly damages the leaves of plants, and can also infect organs such as petioles, peduncles and petals.

After the leaf is susceptible, it usually starts to change color from the edge and appears water-stained lesions, and then the lesions gradually spread to the whole leaf, and under the condition of high humidity, the surface of the diseased part is covered by a layer of gray-green mold!

Spraying should be done in time before the larvae hatch and before serious disasters occur. The agent can be used 1000 times of 90% trichlorfon or 1000 times of malathion. Also known as cabbage borer and borerworm.

The larvae are boring pests, which harm the heart leaves and leaves of Chinese cabbage seedlings, and the damaged seedlings stop growing or wilt and die due to the destruction of the growth point, resulting in lack of seedlings and broken ridges. Chinese cabbage cannot form balls after being damaged. It can also spread soft rot.

Vegetable borer, belonging to Lepidoptera, Moth Moth, Wild Borer, also known as radish borer, cabbage borer, cabbage borer, cabbage borer, cabbage borer, etc., commonly known as drill heart worm, heart worm, heart worm, etc. In our country's wide distribution area, in the southern vegetable area of the damage is heavier, in the process of planting Chinese cabbage, it is easy to appear vegetable borer, vegetable borer is also called borer, its larvae mainly eat vegetable seedlings cabbage, but also spit silk weaving nets, the appearance of vegetable borer insect pests will find that there are many wire nets at the cabbage heart, light will affect the growth of vegetable seedlings, with its larvae to eat cabbage heart, the larvae that have just been generated will crawl to the cabbage heart spit silk weaving into a net, hidden in it to eat the cabbage heart, resulting in a destructive lack of seedlings, the whole plant is eaten and so on to form a headless or multi-headed or even lack of plants. Loss of yield due to loss of plants or wilting.

Also known as black mold, it is one of the common diseases in mustard, mainly for the leaves, stems, petioles, peduncles and seed pods can also be damaged. Leaf infection, mostly from the outer leaves, produce nearly circular gray-brown spots, yellow halo around the lesions, there are obvious concentric wheel patterns, mustard is a kind of mustard, its growth likes temperature but is afraid of high temperature, likes cold and is afraid of severe cold, likes humidity but is also afraid of waterlogging. Therefore, it can be planted in large areas in Sichuan and Chongqing in the southwest, while it is relatively less planted in Hunan, Hubei, Zhejiang and other places in the south.

Reasonable crop rotation: the reserved land should be rotated with rice and wheat and other undergraduate crops, especially the nursery field, and it is required that no cruciferous crops have been planted within three years; selection of excellent varieties that are resistant to viruses; Sowing seeds at the right time, the temperature is selected to sow at 20 to 25 degrees, also known as black mold, is one of the common diseases in mustard, mainly for the damage to leaves, stems, petioles, peduncles and seed pods can also be damaged. The leaves are infected, mostly starting from the outer leaves, producing nearly circular gray-brown spots, yellow halos around the lesions, and obvious concentric wheel lines.