What are the diseases of garlic and how to prevent them?

Common garlic diseases include garlic leaf blight, garlic rust, garlic gray mold, garlic Sclerotinia sclerotiorum, garlic bacterial soft

What are the diseases of garlic and how to prevent them?

Common garlic diseases include garlic leaf blight, garlic rust, garlic gray mold, garlic Sclerotinia sclerotiorum, garlic bacterial soft rot, garlic Fusarium wilt and so on.

Garlic leaf blight: After the disease occurs, spray 80% zineb 600-800 times solution or 75% chlorothalonil 600-800 times solution on the leaves every 7 days 1 time.

Garlic rust: At the onset, spray 2000 times of 20% triadimefon EC or 3000 times of 25% dipyridamole EC 1 5 days on the leaves. ......

I. Garlic leaf blight

1, symptoms

Garlic leaf blight mainly harms leaves. At the beginning, the lesions showed small white spots, and then gradually expanded into irregular or oval gray-white or taupe lesions, with black mold scattered in black particles. When the disease is serious, the whole plant leaves wither and die.

2, prevention and control methods

(1) After the garlic is harvested, the diseased leaves and yellow leaves in the garlic field should be taken out of the field in time and burned or buried deeply.

(2) Before sowing, seed was dressed and soaked with 50% carbendazim wettable powder, and the dosage was about 0.3% of the weight of garlic seeds.

(3) Prevention and treatment with 70% ethyl phosphate aluminum manganese zinc wettable powder in 500-700 times, once every 7- 10 day, 2-3 times in a row.

(4) After the disease occurs in the field, dilute and spray with150g of 40% carbendazim colloidal suspension and150g of potassium dihydrogen phosphate once every seven days for 2-3 times, or spray 80% zineb 600-800 times (or 75% chlorothalonil 600) on the leaves.

Second, garlic rust.

1, symptoms

Garlic rust mainly harms leaves and pseudostems. At the beginning of the lesion, it was spindle-shaped chlorosis spot, and a slightly convex round or oval pile of summer spores appeared under the posterior epidermis, which was scattered in orange-yellow toner after rupture. There is a yellow halo around the lesion. With the aggravation of the disease, the diseased spots become one piece, which leads to yellowing of leaves and premature death of plants.

2, prevention and control methods

(1) Reduce irrigation times to avoid flooding. In case of long-term rainy weather, ditch and drain in time.

(2) Choose garlic varieties with strong disease resistance, such as purple garlic, Xiaoshikou garlic and Shucheng garlic for cultivation.

(3) At the initial stage of the disease, spraying 15% triadimefon wettable powder 1500 times or 97% fenoxamide wettable powder 300 times, 25% triadimefon emulsifiable concentrate 3000 times, 20,000 times, 25% triadimefon emulsifiable concentrate 4000 times and10 times. 70% mancozeb WP 1000 times solution+15% triadimefon WP 2000 times solution control, 10- 15 days 1 time, 1-2 times.

Third, garlic gray mold

1, symptoms

Garlic gray mold mainly harms leaves. At the beginning of the disease, there are faded white spots on both sides of the leaves, and then gradually expand into long or spindle-shaped lesions, resulting in most leaves turning yellow. When the air humidity is high, a gray downy mildew layer will appear, which will turn the leaves brown or rot like water stains.

2, prevention and control methods

(1) After garlic is harvested, the sick and disabled in the field should be cleaned up in time.

(2) For garlic cultivated in greenhouse, ventilation and humidity reduction should be carried out in time to avoid excessive air humidity.

(3) In the case of garlic in the open field, at the initial stage of the disease, spraying 600-800 times of 50% mirex wettable powder or 800- 1000 times of 40% carbendazim sulfur gel suspension, 50% propargyl wettable powder 1000 times of liquid and 50% prochloraz wettable powder/kloc on the leaves.

(4) Garlic is cultivated in greenhouse. At the initial stage of the disease, 50g Tektronix smoke agent or 250g 45% chlorothalonil smoke agent is used in every 100 cubic meter of space and smoked every 7-8 days. Or spray 1 kg 10% chlordecone dust agent or 5% chlorothalonil dust agent per mu at night, once every 9 days.

Four, garlic Sclerotinia sclerotiorum

1, symptoms

(1) Sclerotinia sclerotiorum mainly harms pseudostems and bulb bases. At the beginning of the disease, the diseased spots were waterlogged, and then the diseased spots became dark or gray ulcer rotted, and the rotten parts smelled of garlic. When the humidity is too high, white wool-like hyphae appear and ulcers rot.

(2) After the leaf sheath of garlic rotted, the leaves wilted, turned yellow and died, the root and disk of garlic rotted, and garlic scattered petals.

2, prevention and control methods

(1) After garlic is harvested, plow the land in time, and the appropriate tillage depth is about 20cm.

(2) Before sowing, bleach the seeds with 10% salt water for 2-3 times to remove sclerotia.

(3) Before planting, 20 kilograms of fine soil and 0.5 kilograms of 20% methyl chlorophosphonic acid are mixed into medicinal soil per mu and spread all over the field.

(4) Spraying 5% chlorothalonil powder at the dosage of 1kg/ mu immediately when there is an ascot in the open field. Or spraying 1000 times of 20% methylprednisolone emulsifiable concentrate or 1000 times of 50% iprodione, 1000 times of 50% nongliling wettable powder, 1500 times of 50% iprodione wettable powder and 30% methyl sulfide on the leaves in full bloom.

Five, garlic bacterial soft rot

1, symptoms

Bacterial soft rot of garlic mainly harms leaves. At the onset, it starts from the leaf margin or midvein, and then forms yellow-white stripes along the leaf margin or midvein, running through the whole leaf. When the humidity is too high, the diseased spots appear yellow-brown and soft rot, and eventually the whole plant withers or dies.

2, prevention and control methods

(1) implement crop rotation to avoid continuous cropping.

(2) Before sowing, seed was dressed with 1 kg 77% Keith Downing wettable powder per mu.

(3) At the early stage of the disease, 500 times of 50% copper succinate wettable powder, 500 times of 77% bactericide micropowder and 300 times of 14% copper complex solution were sprayed on the leaves to prevent and control the disease, once every 7- 10 days and once every 2-3 times.

Six, garlic wilt

1, symptoms

Garlic Fusarium wilt mainly harms leaves. At the early stage of the disease, pale yellow to pale yellow water spots appeared in the middle or above the blade tip, with light green edges, and then the disease spots gradually expanded, leading to leaf withering. When the humidity is too high, the diseased spots rot and sparse gray mold appears.

2, prevention and control methods

(1) Garlic varieties with strong disease resistance such as Cangshan Garlic, Purple Garlic, Ning Garlic 1, Su Garlic and Hard Tail were selected for cultivation.

(2) Onion and garlic vegetables shall not be planted in the affected plots for 2-3 years.

(3) At the initial stage of the disease, foliar spraying 400-500 times of 64% antiviral alum wettable powder or 250 times of 40% phosphonoalumine wettable powder, 500 times of 58% metalaxyl manganese zinc wettable powder and 800- 1000 times of 72% gram green wettable powder. If bacteria are resistant to the above drugs, 69% Anke Mn-Zn wettable powder 1000 times solution can be used for prevention and treatment.