What is the difference between downy mildew and gray mold in spinach? How to prevent it?

In the process of vegetable cultivation, gray mold and downy mildew.

It is a common disease. Both are fungal diseases, but the onset of symptoms is completely different.

Botrytis occurs during both the seedling and growing phases and mainly damages leaves, flowers, stems and fruits. When the leaves are damaged, they will become gray-brown lesions, and they will form a V-shaped and expand inward. Whether it is a leaf or a fruit, when the humidity is high, a gray mold layer will grow.

The fruit is infected, the green fruit is seriously damaged, and the remaining stigma or petals are mostly infected first, and then expand to the fruit, resulting in the peel being gray-white, and there is a thick gray mold layer, which is water rotten. The leaf disease starts from the tip of the leaf, and the lesion expands inward in a "V" shape along the leaf veins, grayish-brown, with dark and light striated lines, and the boundary between disease and health is clear.

The prevention of gray mold should pay attention to the temperature and humidity, about 20 degrees, and it is easy to get sick when the humidity is high. As the temperature rises and the humidity decreases, the condition gradually weakens. In the planting process, partial application of nitrogen fertilizer, ventilation, light, too dense planting, and unfavorable moisture drainage will cause the occurrence of gray mold.

For gray mold drugs, you can use 300 times the sclerotia to hit the ground, do not beat the seedlings. Foliar spray with 600 times of pyrimethylamine, 50 times of 400 times of Sucre, 50 times of promethane 400 times, BASF.

Kaiser 1000 times liquid, Syngenta.

300 times the solution of Sedford, 500 times the solution of eugenol, these drugs can be used once every 5 days. Squirt 2 times in a row.

Downy mildew mainly affects leaves and stems. When the leaves are infected, a white mold layer will appear on the back of the leaves, and the diseased leaves will also roll upward, and the leaves will fall off easily. Mainly because of the influence of temperature and humidity, it is close to gray mold.

The most typical feature of downy mildew is the reverse side of the leaf, and the leaf vein is the boundary disease.

When the air is humid, a frosty mold layer is produced on the back of the leaf, and the disease spots are dead and patchy in the later stage, which is yellowish-brown.

Downy mildew drugs can be used for the prevention and control of antibiotics, enoylmorpholine, silver farry, downy mildewcarb, methamethal, octrithin ester, etc., in order to prevent drug resistance.

Fungicides should be used alternately. Case-by-case analysis.

Hope it can help you.

Downy mildew is caused by fungi belonging to the subphylum Flagellates whereas Botrytis is caused by fungi belonging to the subphylum Hemifungi as all are caused by fungi and some of the drugs used can be shared.

The biggest difference between the two of them is that the degree of harm of this germ between them is not the same, the first point, saying that there is no disease is actually a double, and then forming a bacterium, which is very dangerous, and the second point is that gray mold is basically a bug on it, and their best prevention and control method is actually spraying.

Spinach downy mildew is a fungal disease. Downy mildew overwinters with hyphae on overwintering spinach and seeds, or oospores in diseased residues, and is the main source of infection through airflow, rain, insects and tillage. Recurrent infections in temperature, rain, and humidity of 7-16 degrees.

Downy mildew is caused by lack of vigor, high planting density, moisture or early sowing, and in severe cases, it can lead to non-harvesting. Spinach downy mildew mainly damages spinach leaves. At the beginning of the disease, the leaves produce pale green spots, which develop into pale yellow spots, and then expand into irregular spots with a white mold layer on the dorsal spots of the leaves.

The lesions spread upwards from the lower part of the plant and are prone to illness at night when there is dew. The diseased leaves turn yellow in drought, rot when wet, turn yellow and die in severe cases, and spinach downy mildew is serious in low temperature and high humidity environment.

Downy mildew prefers low temperature and high humidity environment, spinach is more susceptible to downy mildew infection from the five-leaf stage to the harvest stage, the bacterial incubation period can reach 5 15 days, and it will cause disease in the temperature environment of 3 30. The incidence is higher when the relative humidity of the air reaches 85% at 7 15. At the peak of the disease, continuous rainy weather, or rainfall of more than 50mm, will definitely cause the disease. Downy mildew fungus safely lurks in the field in winter or summer, mycelium parasitizes on spinach residues, and mycelium can also safely parasitize seeds in winter or summer; In the spring of the following year, the hyphae reproduce conidia under suitable environmental conditions, and the conidia are disseminated by air currents, rainwater, insects, farming, etc.

The pathogen spreads to the spinach plant, and then the stomata or epidermis of its host leaf invades first, causing the spinach to be infected with the disease for the first time. At the right temperature and humidity, it only takes 2 to 3 days for the germs to invade the disease.

After the occurrence of spinach disease, downy mildew sporangia will breed, and the sporangia will be spread through air currents, rainwater, insects, tillage, etc., resulting in spinach being infected with downy mildew many times. The rapid multiplication of downy mildew at its peak can lead to multiple infections of spinach. The damage of downy mildew to spinach plants is mainly manifested in the leaves.

Spinach leaves are infected with downy mildew. The pathogen first invades the leaves close to the ground, and the pathogen spreads from top to bottom. In the early stages of the disease, yellowish spots can be seen on the leaves.

As the pathogen spreads, irregular spots appear, and the spots have no noticeable edges. The infected site on the back of the infested leaf will develop a layer of downy mildew, which is also the sporangia of downy mildew. The pre-mold layer is grayish-purple or grayish-white.

When the lesions develop to the middle and late stages, the mold layer will turn yellowish-brown-orange. When the climate is dry, the affected leaves turn yellow, and when the air is humid, the affected leaves rot and turn brown. In severe cases, the lesions will break into pieces and turn yellow or brown, and most of the leaves of the affected plants will turn yellow and die.

The seeds are sown with bacteria, and after germination, they become infected with germs, the seedlings shrivel, and the leaves become smaller and brittle. When the air is humid, the mold layer also multiplies on the leaves, which are also the sporangia of downy mildew, which are spread by air currents, rainwater, insects, farming, etc. When the disease is severe, the seedlings wilt and die.

Select disease-resistant varieties, adjust the temperature and humidity in the shed in time, strengthen field management, the planting density should not be too large, scientific watering, reduce the humidity in the shed, increase phosphorus and potassium fertilizer, and improve plant disease resistance.

Seed Treatment: 58% of the usable seed weight (Methyl Frost?) Manganese-zinc) wettable powder or seed weight of 50 Fumei double wettable powder dressing. Pesticide prevention and control: timely spraying prevention and treatment in the early stage of the disease.

It can be prevented with drugs. Some pesticides can prevent downy mildew in spinach.

In such a situation, it should be watered and fertilized in time, and pesticides should be sprayed in time, and it is also necessary to prescribe the right medicine, and it should also maintain ventilation and light to keep the soil fertile.

In the early stage of the disease, timely spraying can be used to prevent and control 58 Lusujing wettable powder 800-1000 times, or 75 chlorothalonil wettable powder 600-800 times, or 64 frost manganese zinc wettable powder 800-1000 times, or 72 downy mildew wettable powder 800-1000 times, or 72 frosturea? Manganese-zinc wettable powder 700-800 times liquid, or 69 enoylmorpholine manganese-zinc wettable powder 1000-1500 times liquid, or 70 ethylphosphine aluminum? 500-600 times of manganese-zinc wettable powder, or 500-600 times of 50 times of copper wettable powder, or 600-800 times of 80 spreedacen zinc wettable powder, spray once every 7 days, and continuously control 2-3 times.

Pesticides should be applied alternately to prevent pathogens from developing resistance.

Spinach downy mildew.

It is no stranger to vegetable farmers, because the disease will reduce the yield of spinach, and at the same time, the quality of spinach is not good enough, and it cannot be sold at a good price, so the prevention and control of downy mildew is urgent.

First, the occurrence law of spinach downy mildew.

1.On overwintering vegetable plants and seeds with pathogenic bacteria hyphae.

Overwintering or overwintering with oospores in diseased carcasses. The following spring, the sporangia will be produced under suitable environmental conditions, spreading through air currents, rain, farm implements, insects, and tillage operations. The suitable temperature for the onset of the disease is 8-10, high 24, low 3.

When the temperature is 10, the relative humidity.

85%, or the planting density is too high, and when the vegetable field is waterlogged, it will become seriously ill as soon as possible. In cold and rainy climates, disasters often erupt.

2.As the disease progresses, the pale green spots gradually expand into irregular, severe spots. When the weather is dry, the spinach leaves dry out.

Yellow. In case of wet weather or concentrated precipitation, a gray-white mold layer grows on the back of spinach leaves, and when the mold layer turns purple-gray, it means that spinach leaves have basically rotted. This is the main feature of downy mildew in spinach in the field.

3.When spinach downy mildew center disease plants appear in the field, they should be uprooted and destroyed immediately. The spinach produced in the shed should be ventilated and dehumidified in time, and the spinach that is too dense and too fine should be picked.

4.Spinach downy mildew Symptoms of Spinach downy mildew usually start from the lower leaves, with pale green waterlogged spots in the early stage of the disease with inconspicuous edges, and later develop into yellow irregular spots. When the humidity is high, a grayish-white mold layer is formed on the back of the leaf, which gradually turns dark gray.

When the greenhouse is dry, the diseased leaves gradually turn yellow and dry, and the air humidity.

When it is large, the diseased leaves become moldy. Spinach downy mildew occurs as a fungal disease caused by an oomycete. Downy mildew is easy to be induced when the temperature is low, the air is humid or the field is humid, the planting is too dense, and the ventilation between plants is poor.

It is generally severe in continuous cropping plots and overwatered sheds.

2. Agricultural control measures for spinach downy mildew.

1.Seriously ill fields are rotated for 2-3 years. Apply well-rotted organic fertilizer to improve the disease resistance of plants.

2.It is a reasonable dense planting and scientific watering to prevent flooding and the spread of diseases with the water flow. Strengthen ventilation and reduce humidity.

3.If a diseased plant infected with downy mildew is found, it should be uprooted in time and taken out of the field for burning or deep burial.

4.Sprinkle with quicklime.

Treat the planting holes to prevent the spread of germs. At harvest time, the remaining leaves are thoroughly removed and taken out of the field for deep burial or incineration. Chemical control. At the beginning of the disease, 75% chlorothalonil can be sprayed.

500 times of wettable powder, and 58% methyl frost manganese-zinc wettable powder 500 times or 69% alkene-manganese-zinc wettable powder 800 times liquid can be sprayed when the condition is severe. Spraying every 7 days, 2-3 times in a row, can effectively control the spread of downy mildew. Foliar fertilizers and plant growth regulators can also be sprayed.

Take control and get better.

First of all, pesticides should be sprayed in time, and then weeds should be removed regularly, we must prescribe the right medicine, choose the right fertilizer, and prune the branches and leaves in time to avoid rotting, and be sure to add the right amount of water to dilute the pesticides.

Apply fully corroded organic fertilizer, improve the disease resistance of plants, properly water, prevent and strengthen ventilation, reduce humidity, and find that infected bacteria should be pulled out in time and burned in the field or buried deeply.

Pesticides can be used in advance for prevention, or water and fertilizer management can be done well, and the virus can be prevented by controlling temperature.

Spinach downy mildew often occurs, how to prevent spinach downy mildew?

1.Seed harvesting from disease-free fields. Or use 25% methamethamine wettable powder for seed dressing.

2.In the south, it is cultivated in high chambers to facilitate drainage and ventilation. Northern and protected land cultivation takes sparse sowing and early seedlings.

Commonly used agents such as 31% methyl cream eugenol frost urea wettable powder, 45% enoylbenzylthiamine aqueous agent, 72% eugenol downy mildew carb water emulsion, 60% enoyloxystrobin water dispersible granules, 50% fluopyramide cyanoshalozole water agent, 65% pyraclostrobin cyanosmulate azoxystrobin suspension, can also be used 200 grams of 45% chlorothalonil tobacco agent per mu, smoked in a closed shed for 6-8 hours in the evening; After the occurrence of the disease, 800 times the solution of Pulik water solution or 72 frost urea can be used.

Reasonable dense planting, scientific watering and fertilization, pay attention to heat preservation and ventilation in the shed, diligent cultivation, frequent weeding, and timely cleaning of diseased plants, reduce the source of pathogens in the field, after spinach harvest, clean up the diseased plants and other sundries in the field in time, and bury them deeply or incinerate; Choose high-yield, harvest-free, disease-resistant, disease-resistant spinach seeds. Medicate the spinach seeds before sowing. Reduce primary pests and diseases.

After the spinach grows to 5 leaves, it is prophylactically sprayed with mancozeb 1:1500 times aqueous solution spray for downy mildew or sprayed with carbendazim 1:1800 times aqueous solution for prevention.

Spray with methalene, manganese, morpholine, and silver farix. It is advisable to spray early, and spray from the bottom to the top with a nozzle when the blade does not completely cover the ground, spraying the back of the blade. Downy mildew infects from the dorsal of leaves.

In addition, the cause of the occurrence of the disease is also related to continuous cropping fields (heavy cropping fields), which often become the source of infection in the following year due to the accumulation of pathogenic bacteria, and the meristids of the pathogenic bacteria are transmitted by air currents, irrigation water, farm tools, insects, etc.

Spinach downy mildew incidence is high, causing serious losses to the yield of spinach, and it is necessary to throw away it in time if it is found to be mildew.

Symptoms of cinerine mold in vegetables. The disease is mostly from the leaves close to the surface, the initial disease part is water-soaked, and the disease part expands rapidly when the humidity is high, and it is brown or light reddish-brown, causing rot, and the disease part has gray mold. The base of the stem is diseased, the diseased part becomes brown and rotten, and there is gray mold control method to select soil for 2 3 years of rotation.

Choose new seedbeds or field seedlings without pathogenic bacteria to cultivate disease-free and strong seedlings. In the morning of cultivated in the protected area, the humidity should be reduced by wind, then the shed should be closed to increase the temperature, and the humidity should be reduced to below 75% in the afternoon. Prevents condensation on leaves at night.

<> meet the needs of the market, the types of vegetables are very diverse, such as new fast vegetables, chrysanthemums, etc., some of which I can't name. In order to meet the market demand, the planting area of vegetables has also expanded. However, in the past two years, the incidence of gray mold has gradually increased in the planting process of farmers, and gray mold can occur in vegetables in protected areas or open fields, and has also become one of the important diseases of vegetables, mainly harming fruits, causing rotten fruits, and generally reducing yields by 20%-30%.

Strengthen management: increase some trace elements, rational use of nitrogen fertilizer, enhance the resistance of vegetables, reasonable irrigation, humidity control below 80%, etc.

or rotation with non-host plants, which can reduce the base of soil pathogens and reduce the incidence. And carry out soil treatment, and after the vegetables in the spring stubble protected area are pulled seedlings, the diseased plants in the field are cleaned. Strengthen cultivation management, the base fertilizer is mainly fully decomposed organic fertilizer, and the low temperature and high humidity are the best conditions for the onset of gray mold, and high humidity is the main factor for the incidence of gray mold.

The temperature suitable for the development of Botrytis cineris is 21 - 23, if the humidity in the air continues to reach more than 90%, it is the peak period of Botrytis incitrea. Reduce humidity, ventilate, control watering. As a precaution, it is recommended to take the above measures; The prevention and control of gray mold special agent + bacterial agent comprehensive spray, or smoke ,......The most obvious manifestation is that there will be a mold layer on the surface of the leaves, both on the front and back, but the most serious part of the disease is the fruit, the epidermis of the fruit of the bean fruit invades into a white water immersion, and then the fruit begins to rot, and eventually the bean is not yet.