Symptoms and Control Methods of Garlic Soft Rot
Garlic (Garlic), also known as garlic bulb, garlic head, hu garlic, hu, single garlic, single-clove garlic, is the collective name for plants of the garlic group. A half-year herbaceous plant of the lily family, genus Allium, with the bulb used as medicine. Harvested in spring and summer, tied in bunches, hung in a ventilated place, dried in the shade for later use. As the farming proverb says, “plant garlic before the ninth (month), after the ninth it grows single cloves”. When the leaves wither in June, dig it up, remove the mud and sand, dry it in a ventilated place or roast it until the outer skin is dry. Garlic is flat-spherical or short-conical in shape, with a grayish-white or light brown membranous scale skin on the outside. After peeling off the scale leaves, there are 6 to 10 garlic cloves inside, growing in a ring around the flower stalk, with a disc-shaped stem base bearing many fibrous roots. Each garlic clove is wrapped in a thin membrane; peel off the membrane and the white, thick, juicy scale is revealed. It has a strong garlic pungency and a spicy taste. It has an irritant odor, can be eaten or used for seasoning, and can also be used as medicine. The underground bulb is divided into cloves and, according to skin color, is divided into purple-skin varieties and white-skin varieties. Garlic was introduced to China from the Western Regions during the Qin and Han dynasties. Through artificial cultivation and breeding, it has anti-cancer effects and is deeply loved by the public as food.
Garlic is rich in nutrients: every 100 grams contains 69.8 grams of water, 4.4 grams of protein, 0.2 grams of fat, 23.6 grams of carbohydrates, 5 mg of calcium, 44 mg of phosphorus, 0.4 mg of iron, and 3 mg of vitamin C. In addition, it also contains thiamine, riboflavin, nicotinic acid, allicin, citral, and trace elements such as selenium and germanium. It contains about 0.2% volatile oil. The main component in the oil is allicin, which has a bactericidal effect and is produced when alliin contained in garlic is hydrolyzed under the action of alliinase. It also contains various sulfur ether compounds composed of allyl, propyl, and methyl groups.
Garlic contains “alliamine”, a substance whose benefits to the brain are many times stronger than vitamin B. Letting children eat more scallions and garlic in daily life can make the growth and development of brain cells more active. Garlic is warm in nature and pungent and neutral in taste; it enters the spleen, stomach, and lung meridians. Patients with yin deficiency and excessive fire and patients with chronic gastritis or ulcers should eat it cautiously. External use can cause skin redness, burning, and blistering, so it should not be applied for too long, and those with skin allergies should use it cautiously.
Garlic has antibacterial and anti-inflammatory effects, can protect the liver, regulate blood sugar, protect the cardiovascular system, resist hyperlipidemia and arteriosclerosis, and resist platelet aggregation. Nutrition experts have found that garlic extract has an anti-tumor effect and recommend eating 3—5 grams of raw garlic daily. Although garlic has the effects of killing insects, detoxifying, dispelling cold, and strengthening the stomach, its nature belongs to a damp-heat item and it is also irritant, capable of irritating the liver, lungs, stomach, and eyes. If suffering from liver heat or hepatitis, severe spleen-stomach fire, eye pain, or inflammation, it is advisable to avoid it. Eating too much garlic damages the spleen, harms the lungs, damages the liver, harms the ears, produces phlegm, and causes coughing.
Symptoms and control of garlic soft rot
Harmful symptoms of garlic soft rot:
Garlic first develops the disease from the leaf margin or midvein, forming yellow-white stripes along the leaf margin or midvein, which can run through the entire leaf. When humidity is high, the diseased part becomes yellow-brown and soft-rotted. Generally, the lower leaves develop the disease first, then it gradually spreads upward, causing the whole plant to wither and turn yellow or die.
Control methods for garlic soft rot:
Strengthen cultivation management
1. Before sowing, optimize and carefully select garlic seed, and use virus-free, disease-resistant, pest-free garlic seed as much as possible.
2. Choose a plot whose previous crop was not an allium vegetable, and choose loam soil that is flat, convenient for drainage and irrigation, rich in organic matter, and strong in fertilizer and water retention capacity for planting. When preparing the land, deep plow, sun the clods, and harrow level, so that the upper layer is loose and the lower layer is firm.
3. Use formula fertilization, apply sufficient decomposed organic fertilizer and cake fertilizer, and increase the application of phosphorus and potassium fertilizer to promote robust seedling growth, improve disease resistance during the pre-year green garlic seedling stage, and reduce the occurrence of physiological diseases.
4. Sow at the right time. Grasp the suitable sowing period, water thoroughly after sowing, and cover with plastic film after watering to increase ground temperature, preserve soil moisture, reduce the number of irrigations, and effectively reduce the spread of pathogens through rainwater, irrigation, and other means.
Chemical control
1. Garlic seed treatment: Dress and coat the seed with 2.5% Celest suspended seed coating agent at 0.25% of the seed weight, which can kill pathogens on the garlic body; dress the seed with 50% carbendazim. The seed dressing method is to mix 100 grams of each agent with 5 kg of water, which can dress 50—75 kg of seed. Mix evenly, dry, and then sow. The control effect on soft rot can reach about 95%.
2. Soil treatment: This method is suitable for plots where soft rot has already occurred. Spray the sowing furrow with 3% Diweidan suspension concentrate or 77% Duoning wettable powder at 600 times dilution, spraying 100 kg of liquid per mu, and sow immediately after spraying; mix copper sulfate, quicklime, and plant ash in a ratio of 1:1:100 and broadcast it into the garlic furrow.
3. Foliar spraying: If diseased plants still appear after taking the above measures, spray 77% Kechade wettable powder at 500—800 times dilution promptly at the early stage of disease onset, once every 7—10 days, for 2—3 consecutive sprays; use 75% chlorothalonil wettable powder at 500—800 times dilution to drench the roots and stems. For garlic fields with relatively high soil moisture, applying the pesticide for control as early as possible gives better results.