How does green onion gray mold appear? How to use medicine to prevent it?

Onion gray mold parasitizes onions, causing leaf blight. At the beginning of the disease, the leaves of green onions are white and then turn grayish-brown. A brick-brown layer of mold is produced in the diseased area, i.e., the pathogens conidia and conidia.

At the beginning of the disease, the leaves of green onions are white and then turn grayish-brown. A brick-brown layer of mold is produced in the diseased area, i.e., the pathogens conidia and conidia. Symptom identificationThere are three main symptoms of green onion leaves:

Vitiligo, dry-pointed, and wet-rot. Among them, the white spot type is more common, and the leaves appear white to light brown spots, which expand into prismatic to oblong-oval. When wet, there is a gray-brown mucor layer on the spots, and the spots are connected to each other in the later stage, causing most of the leaves or even the whole leaf to rot and die; The tip of the diseased leaf of the dry tip is waterlogged first, then changes from light green to gray-brown, and there is a gray mold layer in the later stage. The wet leaves are stained with water, and the lesions are slightly green, like boiling hot water.

There are dense green hairs on the spots or at the junction of disease and health. In severe cases, they have an unpleasant odor, turn brown and rot.

The pathogenic bacteria overwinter or overwinter with the diseased host, and the hyphae and sclerotia overwinter or overwinter on the diseased residues in the field and soil, becoming the main source of infection of the host plant in the next season. At the right temperature, humidity and rainfall are key factors in the epidemic of gray mold. Clear-field green onions can be infected at the seedling stage in autumn, and the disease develops slowly in winter, and then spreads again in spring, reaching a peak.

Winter and spring are rainy, precipitation is abundant, and the condition is serious. Choose a loam soil with flat terrain and easy drainage as a seedbed and planting site. Drain water in time after rain.

When soil moisture is high, shallow tillage disperses the water. Reasonable dense planting, strengthen fertilizer and water management, eliminate diseased seedlings in field planting, uproot diseased plants in the field system at an early stage, and transport them out of the field for incineration.

Reasonable dense planting and crop rotation. Clean up rural areas in a timely manner to reduce the source of infection. Sick and disabled plants should be burned in time to prevent the spread of bacteria.

Apply more organic fertilizer, less chemical fertilizer, especially nitrogen fertilizer, increase phosphorus and potassium fertilizer, and enhance plant disease resistance. Frequent tillage to ensure good ventilation and light transmission in the onion field. Drain water in time during the rainy season to prevent high humidity and low temperatures.

Crop rotation should be carried out in the pest and disease area, and the pest and disease residues should be completely removed after harvesting. In rainy areas, the implementation of land destruction, ridge cropping, and high furrow cultivation can be promoted, and timely drainage can be carried out in the rainy season to avoid water accumulation in the field. Because Botrytis cineris is prone to drug resistance, the dosage and frequency of medication should be reduced as much as possible.

When medication needs to be used, care should be taken to rotate or alternate mixtures.

Green onion gray mold, also known as white spot disease, is a common disease in green onion production areas, which only affects green onion leaves. At the beginning of the disease, the leaves produce white spots, which develop from the tips of the leaves downwards and gradually form patches, causing the onion leaves to die. The incidence is particularly severe in winter and spring with low temperatures and rainy seasons.

Main prevention and control methods: 1. Select and cultivate disease-resistant varieties. 2. Reasonable dense planting and crop rotation.

Clean up the countryside in time to reduce the source of infection. Remove the diseased and residual plants in time and burn them in a centralized manner to prevent the spread of germs. 3. Strengthen field management.

Apply more organic fertilizer, less chemical fertilizer, especially nitrogen fertilizer, and increase phosphorus and potassium fertilizer to enhance plant disease resistance. Work diligently to ensure that the onion field is well ventilated and transmitted. Timely drainage in the rainy season to prevent high humidity and low temperature conditions.

Green onion gray mold parasitizes on green onions, causing leaf wilting. At the beginning of the disease, the onion leaves are dry white, and then turn grayish-brown. To prevent and control mildew, disease-resistant seeds should be selected and sprayed in rotation with 50% carbendazim or 70% methyl tobuzine wettable powder 500 times.

Screening and breeding disease-resistant varieties. Reasonable dense planting, rotation implementation. Clean all personnel in a timely manner to reduce the source of infection.

Burn the sick and disabled wine in time to prevent the spread of germs. How to prevent and control green onion gray mold? What medicine can be used to prevent green onions, gray fungal medicine?

Strengthen on-site management. Apply more organic fertilizers, less chemical fertilizers, especially less nitrogen fertilizers, and add an appropriate amount of phosphorus and potassium to enhance plant disease resistance. Cultivate diligently and ensure that the onion battle is well ventilated.

In the rainy season, the water should be discharged in time to prevent the occurrence of high humidity and low temperature conditions.

At the initial stage of the disease, 50% Suclin humidifying powder 2000 times liquid, 2000 wet powder that can be killed 1200 times liquid, 50% black gray net humidifying powder 800-1000 times liquid, 50% water humidification powder 800-1000 times liquid or 40% gray male humidifying powder 800-1000 times liquid Botrytis botrytis is easy to develop drug resistance, the dosage and number of injections should be minimized, and when the drug must be used, it should be used in turns or mixed in turns. At the beginning of the disease, 600 900 times of 3% multi-oxygen detergent, or 300 times of Sterling agent, or 1200 times of 40% gray mold core detergent, or 800 times of 50% gray mold wet powder, or 25% amine (gray leaves of gray mold green onion are dry and rolled, and there is a tendency to spread.

The most important thing for green onion gray mold is prevention and proper organization of field management. Timely organize the field planting environment, reduce the reproduction of pathogens, and select green onion varieties with strong disease for planting. The onions that have been sick should be treated with drugs in a timely manner.

Shui'an humidifying powder 50% 800 1000 times liquid, 50% Sukrin humidifying powder 2000 times liquid can also be used for green onion gray mycosis. Usually sprinkled once a week, sprinkled about three times in a row, green onions grow gray mold, green onion leaves tip white, to timely drug prevention**.

Thrips This is also a very tricky pest in the wild, after the occurrence of thrips and other pests, there will be a large area of dry, yellow, curly green onion leaves, if you don't pay attention, it is easy to think that the green onion has drought. The scallion where thrips appear must be controlled in time, otherwise the quality of the scallion will be severely degraded and the yield will be easily affected. 3% acetamide EC 2000 times, high-efficiency chlorofluorocarbon 1000 times, effective for Toma, can prevent spraying, usually about 3 times in a row, sprayed once a week.

In addition, it is necessary to do a good job in field management, regularly clean up field diseases, disinfect leaves, and apply fertilizer reasonably.

More organic fertilizer should be applied, less chemical fertilizer, especially nitrogen fertilizer, and an appropriate amount of phosphorus and potassium fertilizer should be applied to enhance plant disease resistance. Work diligently to ensure that the onion field is well ventilated and transmitted. Timely drainage in the rainy season to prevent high humidity and low temperature conditions.

Because the gray mold fungus is easy to develop resistance, the amount of medicine and the number of applications should be minimized, and when the drug must be used, it is necessary to pay attention to rotation or alternation and mixed application.

I think if the green onions we grow have gray mold, we must find the best medicine for this disease in the market and spray it on the green onions in time to better work.

You can go to the pharmacy for consultation, and then buy medicine and come back and spray it, so that the effect is very good.

The picture above shows downy mildew.

The following is a one-stop service for green onion planting.

The platform is full of greenery.

Offer. Botrytis cinerea: white spots are produced on the leaves of diseased plants, the spots are fusiform to oblong, 1 5mm long, and the lesions are gathered into plaques when there are many lesions, so that the half or the whole leaf is curled and scorched, and a large number of gray mold layers are born on the dead leaves when wet, and most of them develop downward from the leaf tips, and gradually connect into pieces, so that the green onion leaves curl and die.

Downy mildew: the onset begins in the middle of the outer lobe or at the tip of the leaf, and soon develops upward, downward, and towards the heart lobe. The diseased leaves grown after the bulb was damaged were gray-green, and the severely diseased leaves were twisted and deformed, yellowed and dwarfed, fattened and thickened.

When the humidity is high, the surface of the diseased plant is full of gray-white velvet mold, and there is no obvious single lesion, which is the main feature of the disease, and it is also an important basis for identifying the disease. In wet conditions, diseased leaves are perishable, and when exposed to wind and rain, diseased leaves fall to the rhizosphere, shrink and twist after drying. When the middle and lower leaves are diseased, the leaves above the diseased part droop and dry up, and the disease spreads rapidly, and the leaves seem to be scalded by boiling water.

Then it withered and withered. After the early onset of pseudostems. The growth of the upper part is unbalanced, causing the plant to bend towards the affected side. After the late onset of pseudostem, the diseased part is easy to crack, which seriously affects the seed maturity.

Allium blight: mainly for the damage to leaves, the disease part is initially dark green water-stained spots, when the temperature and humidity conditions are suitable, the disease spots expand rapidly, and the dead parts of the severely diseased fields often reach half of the length of the onion tube, or even 2 3. When the lesion extends to half of the leaf, it becomes wet rot and causes the green onion leaf to droop.

The affected part is yellowed and dried up, only two layers of membranous epidermis remain, and after the stem is damaged, the root disc is water-stained and light brown to dark green rot. The roots are damaged, the root hairs are few, and they turn brown and rot. When the humidity is high, a white sparse mold layer can grow in the diseased area.

Under normal circumstances, the disease spreads downward from the tip of the leaf, and then the leaf curls and dries, and when the humidity is high, there will be a large number of gray mold on the leaf, from above, it can also be distinguished from green onion purple spot and downy mildew. Choose varieties that are resistant to disease. Generally speaking, the green onion varieties with purple stems, thin leaf tubes, and thick wax powder have strong disease resistance, while the false stems are loose, the leaf tubes are thick, the mesophyll is thin, and the disease resistance is poor.

Choose disease-free plots to keep seeds, pay attention to the disinfection of seeds, and close the seedlings.

The original variety of green onion was first introduced, which can be traced back to the Warring States period. Zhangqiu, Shandong, which is famous for the cultivation of green onions in the country, began to grow green onions as early as 681 BC. The most common diseases of cultivated green onions are downy mildew, purple spot and rust.

How can we prevent and control these green onion diseases? The cultivation mode of green onions is diversified, it can be used all year round, and the cultivation of green onions is easy to cultivate with high yield, and it can grow well under general climate and soil conditions. It's just that in the cultivation process, some common diseases also occur from time to time, so that the growth of green onions is inhibited.

Purple spot disease: It can occur at the seedling stage, the growth stage, and the seed collection stage. Generally, roe deer meristem infects adult leaves, leaf sheaths and flower sprouts, and small white spots appear, and finally develops into light brown to dark brown lesions, accompanied by concentric wheel-shaped black mold layer, which is infected during the vigorous growth period and flowering stage, which has a great impact on plant yield.

The main focus of the disease on the green onion is prevention, and if you manage it well, there will be few occurrences of various pests and diseases. Green onions are suitable for growing in well-drained fertile soil, especially in soil with good air permeability, which is more suitable for the growth of green onions.

Caused by bacteria, high temperature and humidity, mechanical injuries, and insect mouth injuries are easy to cause disease epidemics. The symptoms of the disease are that the aboveground part of the green onion is lodging, easy to pull up, the lower part of the stem is rotten, and there is a foul smell. Prevention and control:

Keep the field drained smoothly and do not accumulate water after rain; In the process of field management of green onions, pay attention to the growth of green onions, and take measures to detect and treat them in time. Therefore, it is necessary to spray tributazole as soon as possible, with a 1:1500-fold dilution, or with benziconazole, also with 1:

1500 times dilution spraying.

(1) Selection and cultivation of disease-resistant varieties. (2) Remove the diseased residue in time after harvest to prevent the spread of germs. (3) Strengthen the management of green onion field and adopt formula fertilization technology to enhance the disease resistance of the host.

Reasonable dense planting, so that the onion field ventilation and light transmission, to prevent high humidity and low temperature conditions. (4) Clean the field, clean up the field as a vegetable crop before the implementation of crop rotation, and burn or bury the residual branches and leaves on the ground to reduce the source of infection. Crop rotation can reduce the occurrence of diseases.

Once the disease occurs, the diseased leaves should be removed in time, taken out of the field to burn or buried deeply.

Try to choose excellent varieties, dispose of the infected ones as soon as possible, maintain a good environment, apply fertilizer reasonably, and burn the stumps and leaves of previous crops.

The management of green onions should be strengthened, and proper fertilization should be carried out, so as not to make the land too wet, and some drugs can be used, seedlings can be thinned on green onions, and some disease-resistant varieties can be selected.

When planting green onions, we must choose disease-resistant green onions, and strengthen the management of green onions in the process of planting, so that we can prevent and control green onion gray mold.

First of all, we must choose high-quality varieties, and we must apply more fertilizer, pay attention to light, clean up some residual branches and rotten leaves in time, and spray it with some chemicals that make it good.

Spray pesticides in time to prevent and control, and pay attention to a simple treatment of weeds in the field, so as to ensure that some pests and diseases can be avoided.

Reasonable dense planting, at the same time to clean the countryside of the virus, reduce the spread of pathogens, and to choose a good agent for spraying, in advance for prevention.

Summary. Chive gray mold mainly occurs under the condition of high humidity and rain, generally in April in spring every year, and the disease is more serious in the rainy season in August and September in autumn, so growers must prevent and control it in time.

At the beginning of the disease, spray 1000 times of 50% azoxycyclic amine water-dispersible granules, or 1000 times of 50% iprodione wettable and clear tremor powder, or 800 times of 50% ethylene sclerotia sclerotinia dry suspension, or 800 times of 26% pyrimethylamine ethylmycocarb wettable powder, or 600 800 times of 50% furimidamine ethylmycocarb wettable powder, or 600 800 times of 50% furymethotrine wettable powder. This bacterium is prone to drug resistance and should be rotated.

Chive gray mold mainly occurs in the humidity, rainy and watery conditions of seepage sails, generally in April every spring, autumn in August and September rainy season is more serious, growers must timely prevent and control the mountain.