Detailed Explanation of Key Points of Comprehensive Garlic Management Technology

In garlic production management, early-stage management is relatively simple, as the plants rely on the nutrients stored in the seed garlic for growth. When they grow to 5-7 leaves before winter, they only need to survive the winter safely. After spring begins, as temperatures rise, garlic roots undergo their second major root flush. After the mother bulb recedes, the plants immediately enter vigorous growth, and it is during this period that garlic yield is formed; at the same time, this period is also a time of high incidence of pests and diseases. Therefore, spring management of garlic should be strengthened to lay a good foundation for a high garlic yield.

1. Management during the greening stage

After "Jingzhe," as temperatures rise, garlic begins to turn green again. During this period, the overwintering mulch on garlic should be removed promptly, the greening water should be applied well, and the greening fertilizer should be applied well. When watering for greening, generally apply 20 kg of compound fertilizer per 667 sq m to promote garlic growth.

2. Management during the mother bulb receding stage

In early April, garlic begins to recede from the mother bulb. This is a period of high incidence of garlic maggots, which also causes yellow tips on garlic. To effectively prevent a major outbreak of garlic maggots and reduce yellow tips on garlic, in late March, spray 50% phoxim emulsifiable concentrate at 1000 times dilution to control adult garlic maggots, water once, and with the water apply 15 kg of urea per 667 sq m and flush-apply 0.25 kg of phoxim with the water, which can effectively alleviate yellow tips caused by mother bulb receding and garlic maggots and promote normal garlic growth. From mid-April, use 50% procymidone wettable powder at 1500-2000 times dilution for spray application to prevent garlic gray mold; use 40% carbendazim at 500 times dilution or fosetyl-aluminum at 600 times dilution for spray application to prevent leaf blight; use 1000 times dilution of Zhibingling for spray application to prevent garlic viral disease. Apply once every 7-10 d, generally for 2-3 consecutive applications.

3. Garlic bolt growth stage

This period is the critical period for garlic growth and the critical period for garlic water and fertilizer demand: water demand accounts for about 40% of the entire growth period; fertilizer demand accounts for about 50% of the entire growth period. During this period, the garlic field should be kept moist, generally watering once every 7 d until harvest. With every other watering, apply 20 kg of compound fertilizer per 667 sq m, and stop watering 3-5 d before harvesting garlic bolts.

4. Garlic bulb enlargement stage

In mid-May, after the garlic bolts are harvested, the garlic bulbs enter the enlargement stage. Attention should be paid to keeping the garlic field moist, generally watering once every 5-7 d, and during the entire garlic bulb enlargement stage, generally water 2-3 times. Stop watering 3-5 d before garlic harvest to facilitate harvesting.

5. Harvest period

1. Garlic bolt harvest period: Harvest garlic bolts begins in early to mid-May. Stop watering 3-5 d before harvesting garlic bolts. There are three standards for harvesting garlic bolts: first, the garlic bolt bends into a large hook shape, and above and below the bract there should be a 4-5 cm long horizontal state (called "throwing the bolt"); second, the bract is obviously enlarged, its color changes from green to yellow, opens and turns white (called "white bract"); third, 4-6 cm of the garlic bolt near the leaf sheath turns slightly yellow (called "throwing yellow"). For harvesting, it is generally ideal to choose noon and early afternoon on a sunny day. When pulling the bolts, care should be taken to protect the garlic leaves, especially the flag leaf, to prevent premature senescence, and to prevent the leaves from being lifted or broken, which would affect garlic bulb growth. When harvesting garlic bolts, they should be harvested cleanly; garlic bolts broken in the middle should also have their lower parts harvested again to prevent secondary growth of garlic bolts, thereby affecting the yield and quality of garlic bulbs.

2. Garlic harvest: In early June, most of the basal leaves of garlic plants dry up, and the upper leaves begin to fade, after which they gradually dry from the leaf tip toward the leaf blade, and the plants are in a soft state. If the garlic stalk is pressed forcefully to one side down to the ground at a certain part and does not break crisply but shows toughness, it indicates that the garlic bulbs are already mature, and harvesting of garlic begins. Stop watering 5-7 d before garlic harvest to prevent excessive soil moisture, rotting of garlic cloves, and loosening of garlic bulbs. During harvest, handle gently and place gently, without knocking or bumping, to avoid damaging the garlic bulbs and reducing their commercial value.

6. Prevention and control of pests and diseases

The main garlic diseases include purple blotch, leaf blight, rust, leaf spot, bacterial soft rot, mosaic disease, and viral disease, among others; the main pest is garlic maggot.

Agricultural control: Select disease-resistant varieties, plant at a reasonable density, practice crop rotation, clean the field, strengthen intertillage and weeding, and reduce the number of pest and disease sources. Harvest at the proper time.

1. Purple blotch

Symptoms: In the field, disease onset mostly begins at the leaf tip or the middle part of the garlic stalk, spreads to the lower part after a few days, initially appearing as slightly sunken white small spots with a slightly purple center, and after expansion becoming yellow-brown spindle-shaped or elliptical lesions; under high humidity, black moldy material is produced on the diseased part, and the lesions mostly have concentric rings and tend to break off from the diseased part.

Control: At the early stage of disease onset, spray 3% polyoxin water agent or 78% Kebo wettable powder or 41.5% prochloraz (Pumeiling) emulsifiable concentrate or 75% chlorothalonil wettable powder, or 64% Sandofan wettable powder, or 50% iprodione wettable powder once every 7-10 d, and stop applying 7 d before harvest; ultra-low-volume spraying gives obvious results.

2. Garlic leaf blight

Symptoms: Mainly damages leaves or leaf stalks. When leaves are infected, it mostly begins at the leaf tip, initially appearing as small round off-white spots, and after expansion becoming irregular or elliptical gray-white or gray-brown lesions, on which black moldy material is produced; in severe cases, diseased leaves die. When leaf stalks are infected, they tend to break off from the diseased part, and finally many small black granule-like spots are scattered on the diseased part; in severe damage, no bolts are produced.

Control: At the garlic bulb flower bud differentiation stage and garlic bolt elongation stage, begin spraying 50% prochloraz wettable powder, or 50% carbendazim sulfonate wettable powder for spray application; when using carbendazim, stop applying 10 d before harvest. Ultra-low-volume spraying gives obvious results.

3. Garlic rust

Symptoms: Mainly infects leaves and false stems. The diseased part initially shows spindle-shaped chlorotic spots, then round or elliptical slightly raised uredinia appear under the epidermis; after the epidermis ruptures, orange-yellow powdery material is released, namely telia that do not rupture the epidermis are produced on the uredinia.

Control: In early spring, promptly inspect disease centers and spray for prevention; choose 15% triadimefon wettable powder, or 20% triadimefon wettable powder or 97% dithianon sodium wettable powder or 25% propiconazole emulsifiable concentrate and spray at intervals of 10-15 d. Ultra-low-volume spraying gives obvious results; stop applying 7-10 d before harvest.

4. Garlic gray leaf spot

Symptoms: Mainly harms leaves. The lesions are long elliptical, initially light brown, later turning gray-white; on both sides of the leaves, fine gray-black moldy material, namely the pathogen fruiting bodies, is produced on the lesions; in severe cases, lesions merge, causing localized death of the leaves.

Control: At the early stage of disease onset, begin spraying 75% chlorothalonil wettable powder, or 50% sulfur suspension concentrate, or 65% metham-sodium wettable powder, or 12% copper abietate emulsifiable concentrate, or 47% copper hydroxide wettable powder, or 50% carbendazim-iprodione wettable powder every 7 d for 2 applications; ultra-low-volume spraying works well, and stop applying 7-10 d before harvest.

5. Garlic viral disease

Symptoms: The whole plant is affected; diseased plants are stunted or leaves are wrinkled and twisted, and some show yellow-green mottling in a mosaic pattern or chlorotic stripes. The underground bulbs of diseased plants become small, causing yield reduction of more than 20%. Aphids occur rampant. Excessive nitrogen fertilizer causing overly vigorous or poor plant growth, or overall insufficient fertilizer, leads to severe disease.

Control: Per 667 sq m, spray 50 g of phoxim or 50 g of imidacloprid plus 50 g of a repellent pesticide to kill aphids, and while repelling aphids also mix in Zhibaosu for spray application to promote plant growth, improve resistance, regularly inspect seedlings, promptly remove diseased plants, and reduce field sources of the virus. At the early stage of disease onset, spray 7.5% moroxydine hydrochloride aqueous solution or 2% ningnanmycin aqueous solution, or 0.5% fungal polysaccharide aqueous solution. Spray once every 7-10 d for 2-3 consecutive applications; ultra-low-volume spraying works even better.

6. Garlic pests

The main garlic pest is garlic maggot, which damages the bulb area, causing garlic cloves to be exposed, unlike finished garlic bulbs, and resulting in a low commercial price.

Control: Prohibit the use of pesticides explicitly banned by the state, such as methamidophos, phorate, monocrotophos, 1605, methyl phoxim, isocarbophos, and methomyl; use 100 g of phoxim pesticide plus 50 g of repellent biological pesticide, and spray with an ultra-low-volume sprayer to kill seed flies and cut off the maggot source, so there will be no garlic maggots. During the mother bulb receding stage, flush-apply 0.25 kg of phoxim with water, which can effectively prevent damage by garlic maggots.

In short, the reproductive growth of garlic depends on garlic leaves. Only when the leaves are robust can they absorb carbon dioxide and, under sunlight, produce chlorophyll to support garlic growth; the surface of garlic leaves has a waxy layer, and only by using conventional low-volume pesticide application technology can pesticide droplets adhere to the garlic leaf surface, and only then will the insecticidal and disease-control effects be good.