White garlic leaf blight is harmful, how to prevent and control white garlic leaf blight?

Garlic leaf blight mainly damages the leaves of garlic. In the early stages of the disease, the leaves will have small white dots starting from the tip of the leaf. These dots gradually develop into an irregular shape, grayish-white in color, and when the surrounding air is moist, the lesions become grayish-brown with black mold.

The plant is obviously dwarfed, and the garlic sprouts are also very fine, and the garlic sprouts cannot be pumped when it is severe, and the diameter of the garlic head is mostly about 5 cm. This situation is generally evident from the end of February to the beginning of March, and the yellow leaves occur in spots at the beginning, especially after 2 to 3 years of continuous stubble.

After the garlic sprout is infected, it is slightly yellow, and the heavy one can not be mossed and died, which seriously affects the quality, and the general disease causes 20-30% loss, and more than 50% of the serious disease; 64% alum, 70% mancozeb, chlorothalonil, pyraclostrobin can also be used. Dysenlian, difenoconazole, amicida, can kill 3,000 diluted spray control, can be combined with potassium dihydrogen phosphate or seaweed fertilizer to supplement foliar nutrition. Seed dressing disinfection:

Before sowing, select the good seeds with strong disease resistance, on the one hand, you can apply the amount of 50 carbendazim mixed with 30 kg of fine soil according to 1 kg per mu, and soak or sterilize the seeds with 50 carbendazim according to the amount of seeds.

During the growth period, foliar sprays such as potassium dihydrogen phosphate and other multi-element foliar fertilizers were applied to cultivate robust plants and enhance disease resistance and stress resistance. When serious diseased plants are found in the field, they are pulled out, and they are buried or burned outside the field. Watering is forbidden to flood irrigation, and timely drainage after rain reduces the humidity of the field.

Low-lying land, poor drainage, insufficient nitrogen fertilizer, phosphorus and potassium application, poor management and weak growth are prone to disease, and the disease is often more serious in years with high precipitation and rainfall and continuous stubble planting plots.

If only rotary tillage is carried out and the soil is seriously deficient, the planted garlic is easy to hang empty, resulting in weak garlic seedlings, and even yellow death, so after the straw is returned to the field, it is best to stop for a period of time and then carry out a deep ploughing, and then plant garlic, and water in time, and then cover the film.

1.If diseased leaves are found, the leaves and peduncles should be removed in time. 2.

Strengthen the management of the field, reasonable dense planting, timely drainage after rain, and improve the disease resistance of the host. 3.At the initial stage of the disease, you can spray 600 times of 75% chlorothalonil wettable powder or 1500 times of 50% promethonin wettable powder.

7 Once every 10 days, 3 or 4 times in a row.

Pesticides. Because my family has been growing white garlic for more than ten years, pesticides are used every year to prevent and control leaf blight, so some pesticides should be used.

1. Eradicate the damaged leaves and peduncles in time. 2. Strengthen field management, reasonable dense planting, timely drainage after rain, and improve the host's disease resistance. 3. At the beginning of the disease, spray 600 times of 75% chlorothalonil wettable powder, or 1500 times of 50% promethane wettable powder, 500 times of 64% alum wettable powder, 500 times of 50% copper succinate wettable powder, 500 times of 60% amber ethylphosphine aluminum wettable powder, 300 times of 14% copper ammonia aqueous solution, 1:

1:100 Bordeaux liquid, once every 7 10 days, 3-4 times in succession.

1) Pre-sowing agent seed dressing and soaking. Peel off the garlic with 50% carbendazim wettable powder, and the dosage is the weight of the garlic seeds.

2) Do not crop continuously, plant other vegetables, clean up the diseased and residual plants in time, burn or bury them deeply, and reduce the source of bacteria.

The specific cause of yellowing of garlic leaves

There are many reasons why garlic leaves turn yellow, which can be broadly divided into physiological and pathological. The main causes of physiological yellow leaves are the application of a large number of chemical fertilizers; The soil is too dry, and the lack of water in the plants causes yellow leaves; Garlic lacks trace elements; The main causes of pathological yellow leaves of garlic are leaf blight, wilt, soft rot, root rot, etc.

Microbial fungus fertilizer root boy can not only be used for seedling disinfection, soil disinfection, and root irrigation, but also can be directly absorbed by plant roots, promote plant growth, inhibit the normal growth of pathogenic fungal mycelium or directly destroy pathogens.

Prevention and control methods of garlic yellow leaves

Garlic planting plots should be planted in rotation, which can effectively reduce the occurrence of various diseases. Garlic planting should be sown at the right time, not too early and not too late, so as to avoid yellow leaves and other phenomena. Garlic fertilization is mainly based on well-rotted organic fertilizer, and used with trace elements, and a small amount of topdressing and irrigation is taken many times to prevent the appearance of yellow leaves.

During the garlic planting period, the occurrence of various pests and diseases should be prevented in time, especially the prevention and control of root rot. For root rot plots or damage, flushing or irrigation of root microbial bacteria fertilizer root boys has a good control effect on the prevention and control of root rot, generally used once every 10 15 days.

What is the best medicine for garlic leaf blight

The specific drugs for the prevention and control of garlic leaf blight include chlorothalonil, carbendazim and other drugs. Symptoms of garlic leaf blight: small white dots will appear on the leaves, which will generally start from the tip of the leaf, and then spread rapidly, and in severe cases, the whole plant will die.

Method of medication: spray 75% chlorothalonil wettable powder (500 times liquid) or 50% carbendazim solution at the onset of the disease, and spray it 2-3 times continuously.

Incidence of garlic leaf blight

This bacterium belongs to the genus Stolonus spp. The key to pathogenic bacteria is to be cultivated in the open field (winter) with mycelium or ascomycetes lost in the soil or on the garlic seed coat (of course, there are many bacteria), and ascospores are released before winter or the following spring, causing initial infection, and then the production rate of conidia in the diseased part depends on wind and rain to spread and re-infect.

The temperature of the bacteria is wide to infect the buds, and the environmental humidity is required to reach more than 90%, and it is best to have water. The onset of the disease depends on the temperature sooner or later, and the severity of the disease depends on the humidity. Therefore, the rainy, low-temperature, low-lying terrain, barren land, continuous garlic land, partial application of basal fertilizer yellow leaf disease lack of fertilizer senescent garlic field, leaf blight is seriously harmed.

(1) Select plots with flat terrain and good drainage, apply enough organic fertilizer and phosphorus and potassium fertilizer, and add micro-fertilizers such as potassium dihydrogen phosphate, Tianda 2116 and Yunda 120 in the growing season to improve plant disease resistance.

2) Remove the diseased and residual plants in time, and bring them out of the field to burn or bury them deeply to reduce the source of bacteria.

3) Spraying prevention and treatment in the early stage of the disease. The agent can be sprayed with 40% carbendazim glue suspension per mu plus kg of potassium dihydrogen phosphate, 60 kg of water, or 1500 times of 50% promethine wettable powder, 800 times of 60% Baitai dispersible granules, 1500 times of 25% azine lipid suspension, 1500 times of 10% difenoconazole dispersible granules, 500 times of 50% copper succinate fatty acid (DT) wettable powder, L: L:

100 Bordeaux liquid, etc., spray once every 7-10 days, alternate medication, and continue to prevent and treat 3-4 times.

Pesticides. Because after the white garlic in my house was sprayed with pesticides, the leaf blight was cured, so pesticides should be used to prevent and control it.

Strengthen field management, which is an important method to control garlic leaf blight. Before planting garlic, the seed coat of the garlic should be stripped and the seed coat and straw should be removed from the field to reduce the infection status of pathogens. The use of plastic mulch mulching cultivation methods can increase ground temperature, protect the environment, reduce irrigation frequency, reduce field humidity, and better prevent the occurrence of diseases.

Remove weeds in time to enhance ventilation and light transmission. Increase the use of organic fertilizers and rationalize the use of nitrogen, phosphorus and potassium to improve the disease resistance of garlic.

When the garlic turns green, it looks dry and pointed, and the leaves are yellow. Among them, leaf blight is a large-scale disease of garlic. Leaf blight infection rate is fast, which can cause a large number of garlic leaves to die, and garlic sprouts are small and of poor quality; Heavy people can't smoke garlic, which affects the yield, and even refuses to harvest and sell, which seriously restricts the development of garlic.

Therefore, special attention should be paid to the prevention and control of garlic leaf blight in early spring. 1.Overview of the symptoms of leaf wilting disease:

Leaf blight is mainly caused by infection with the fungus Ascomycetes, which initially appear white spots and then expand into irregular or oval grayish-white or grayish-brown spots. When wet, black mold grows on the upper part, and there are many black particles scattered on the upper part. When the damage is severe, the whole plant is not patted with moss.

The lesions start at the tip of the leaf and expand from top to bottom. It will dry up along the shoots, and the whole leaf or even the whole plant will die. The peduncle is easy to break off from the diseased part when it is infected, and finally in the diseased area, there are many small black spots, so it does not sprout when the damage is severe.

2.Pathogenesis: Garlic leaf blight is one of the common diseases of garlic.

The disease is characterized by the fact that the plants become dwarfed and have reduced yields, and all the fruits fall off with brown spots on the leaves.

White leaf blight mainly occurs on leaves and leaf sheaths. At first, translucent yellow spots are produced on the leaf margin, and later develop into corrugated yellow-green or gray-green lesions along one or both sides of the leaf margin or along the midrib; The boundary between the sick and healthy parts is obvious; After a few days, the lesion turns grayish-white, and curls inward, looking at a withered color in the distance, so it is called white leaf blight.

B. alba mainly overwinters on rice seeds, straws and rice stakes, and according to Jiangsu research, bacteria in the soil near rice stakes in severely diseased fields can also spread the disease over the years. Sowing diseased grains, the germs can invade through the roots and shoot sheaths of the seedlings. The germs on the diseased straw and rice stump seep into the water flow when they encounter rainwater, and the seedlings come into contact with the bacteria-carrying water, and the germs invade the rice body from the water holes and wounds.

Germination with diseased straw, mulching seedlings, and planting seedlings are conducive to the spread of diseases. Due to the low temperature and low bacterial volume in the early and middle rice seedling stages, the symptoms are generally not visible until around booting. The pus on the lesions can be reinfected by wind, rain, dew and leaf contact.

It was found that the white leaves were relatively yellow, with some brown spots on them, and the infection was also relatively strong, and there were also root rotten, and the humidity was also relatively large.

Garlic leaf blight is one of the common diseases on garlic, which occurs to varying degrees in various vegetable areas, and mainly harms garlic cultivated in the open field. During the garlic growth period, the incidence is severe in years with high precipitation and heavy rainfall. Severe disease often causes diseased leaves to die, plant premature senescence, garlic yield reduction, garlic moss mold rot, which directly affects the yield.

At first, the flowers are small white dots, and then enlarge to irregular or oval gray-white or gray-brown lesions, and black mold grows on them, and many small black grains are scattered on them. When the damage is serious, the whole plant does not smoke moss.

The more effective drug for the prevention and control of garlic white rot is PFF, 90g per mu, followed by promethonyl, 120-150g per mu. PFF is an effective drug for the prevention and treatment of garlic white rot. Strict selection of seeds, as far as possible to establish the original seed base; Garlic in mild areas is used as seeds to reduce the rate of bulb poisoning.

Promote high-body culture of vegetative shoot apex and reproductive shoot apical meristem to remove major viruses in garlic bulbs. Avoid adjacent or continuous cropping with allium plants such as green onions and leeks to reduce natural spread in the field. Spray insecticides to control aphids in garlic fields and surrounding crops to prevent repeated virus infection.

The use of pesticides is described in aphid control. In addition, silver-gray membrane strips can be hung to avoid aphids, strengthen garlic water and fertilizer management, avoid premature aging, and improve plant disease resistance.

Garlic mosaic disease can be controlled with PFC. When cultivating, choose disease-free garlic cloves. At the beginning of the disease, you can spray 300 times of antitoxin agent No. 1, 500 times of 20% virus A wettable powder, 500 times of 20% virus buster, 500 times of 20% virus rather wettable powder, or 1000 times of Zhu Bingling emulsion.

Spray every 5 7 days, 2 sprays 3 times in a row. Garlic mosaic disease is a plant virus disease, which is a latent virus of garlic and mainly harms garlic. Therefore, we should start from understanding the symptoms and laws of the disease, so as to find out how to prevent and treat it.

So let's give you a brief introduction to these aspects to help you use prevention and control methods.

Light bulbs can carry viruses. Sowing bulbs with viruses can spread diseases in the field. It is mainly transmitted by aphids, such as the green onion aphid, which is the main route of transmission.

Sometimes, manual tillage in the field can cause sap friction between plants, which can also cause infection. Where aphids are badly harmed, the disease can also be severe. Light bulbs are toxic and can cause degeneration in future generations.

At first, the veins appear yellow streaks and yellow spots, intermittent, then joined into strips, shortened, and partially curled in the heart leaves. Some of the leaves are deformed and twisted. In injured plants, the rhizomes become smaller and the garlic cloves become fewer.

In severe cases, garlic cloves may become firm. It usually occurs in the wild, and it will soon cause great epidemic harm.

Cultivating non-toxic bulbs can reduce the occurrence of diseases in the field. Detoxification culture and tissue culture are used to eliminate the virus. Do not plant with or next to other onion and garlic vegetables to avoid infection.

Focus on controlling aphids, preventing and controlling aphid infection viruses, and using silver-gray film to avoid aphids. Usually fertilizer and water ** are timely and sufficient, maintain good growth potential, and increase resistance. At the beginning of the disease, spray treatment with 300 times the solution of antitoxin agent No. 1 water solution, and spray it again at an interval of about a week or more, and the small fruit is better, and it can also be treated with 20% virus A wettable powder of 500 times the solution.

There are a variety of drugs to choose from, and choose pesticides with high efficiency and low toxicity. When the disease is severe, the roots are perfused with 250 times the anti-poison No. 1 aqueous solution, and 1 root is perfused with 50 ml of the solution. Half a month, about three times.

Garlic mosaic virus is a serious disease that is not easily eliminated completely. The spread is serious, and aphid control is the key. Breeding virus-free seeds is the fundamental solution.