How to Grow Six-Clove White Garlic? A Detailed Guide to High-Efficiency Cultivation Techniques

Garlic is a traditional export vegetable in China and has now become the vegetable product with the highest single-item foreign exchange earnings. With the rapid development of production, processing, and export, the international market has increasingly high requirements for the appearance and quality of garlic. In 2001, Laiyang City, Shandong Province, introduced Japanese six-clove white garlic and successively conducted trial plantings and promotion in multiple locations within the province, including Yantai, Qingdao, Jinan, and Liaocheng. In 2002, the planting area exceeded 15 hm2. Comparative introduction trials and promotion efforts over several years have shown that six-clove white garlic is an excellent variety mainly grown for garlic bulbs, with good marketability, great potential in domestic and international markets, and high planting returns. The key cultivation techniques are introduced below.

I. Characteristics of six-clove white garlic. The pseudostem is thick and sturdy, with strong growth vigor. The leaves are broad and light green, with 8-9 functional leaves. The garlic bulbs are large with pure white skin, generally 5-6 cm in transverse diameter, and the mass of a single bulb is 40-50 g, mostly with six cloves. The texture is crisp, slightly firm, and mildly pungent, with relatively good quality. The average garlic bulb yield per mu is over 1000 kg. The yield of garlic scapes is relatively low, with a normal scape-emergence rate of only 10-15%. The scapes are thick and firm in texture. The resistance to disease, stress tolerance, and storage tolerance are moderate.

II. Regional adaptability of the variety. Since 2001, through comparative introduction trials and regional trials, it has been found that the growth period of six-clove white garlic is basically the same as that of Cangshan garlic and Soviet garlic. The sowing date is October 10, the emergence date is around October 21, the bulb enlargement period is in mid-May of the following year, and harvest is in early June. It is suitable for planting in Shandong and surrounding areas.

III. Key points of cultivation techniques

1. Seed selection and garlic seed treatment. Select garlic bulbs that are round and regular in shape, 3.5-5 cm in diameter, with six cloves, neat cloves, and pure white skin as seed garlic. Separate the cloves and carry out grading. Generally, they are divided by the weight of 100 cloves into 3 grades: 400-500 g, 500-800 g, and over 800 g. Before sowing, soak the seeds for 10 minutes in a mixed solution of 1000-fold phoxim and 500-fold carbendazim. The soaking must be uniform, and the solution concentration should not be too high; otherwise, it will affect the growth of the garlic root system and stems and leaves and reduce the emergence rate.

2. Sowing. In the Shandong region, sowing is generally done in early to mid-October. Six-clove white garlic has high yield and high fertilizer and water requirements, so sufficient base fertilizer should be applied all at once, with heavy application of organic fertilizer. When plowing, evenly apply 5000 kg of high-quality farmyard manure per mu or 2000 kg of decomposed dry chicken manure, along with 20 kg of potassium sulfate and 25 kg of diammonium phosphate. For sowing, either small raised beds or flat beds can be used. The row spacing is 20 cm. For cloves with a 100-clove weight over 800 g, the plant spacing is 12 cm; for 500-800 g, the plant spacing is 10-12 cm; for 400-500 g, the plant spacing is 10 cm. The sowing furrow is 5-6 cm deep, covered with 4 cm of fine soil. If the soil moisture is poor, water first to build moisture, sow after the surface is slightly dry, then rake the bed surface level after sowing and spray herbicide. Alternatively, after sowing, first level the bed surface, water thoroughly, rake the bed surface level after the soil surface is slightly dry, and then spray herbicide. Apply 200 mL of 33% pendimethalin emulsifiable concentrate per mu diluted with 75 kg of water and spray evenly to wet the ground, then cover with plastic film.

3. Field management. Seedlings emerge about 10 days after sowing. If the plastic film is tightly attached to the ground, most seedlings will break through the film and grow out, while a small number will need manual assistance to break through the film in the early morning or evening. No topdressing is needed at this stage. After full emergence, water once. In late November, before the soil freezes, water once to help increase soil heat storage and reduce freeze damage.

From late February to early March, as temperatures rise, garlic begins to resume green growth. At this time, the temperature is still low, so do not rush to water. Generally, in early to mid-March, depending on temperature and soil moisture, water once for green-up.

Because the cloves of white garlic are relatively large, cloves generally over 8 g are prone to splitting, forming two or more seedlings, which consumes nutrients. Weak seedlings should be removed as early as possible, and at the latest around March 20 when the garlic mother clove recedes. Generally, around May 10, pinch off the garlic scapes about 13 cm above the ground. After that, check frequently and promptly pinch off any enlarged flower buds found in the pseudostem to reduce nutrient consumption.

Garlic growth requires sufficient water and fertilizer, so timely watering and topdressing are necessary. The first topdressing is in late March, applying 15 kg of ternary compound fertilizer per mu combined with watering. After that, the second and third topdressings are carried out in mid-April and early May respectively, each time applying 10 kg of urea per mu with irrigation. No more topdressing is done about 1 month before harvest. After entering May, temperatures are higher, garlic growth is greater, and water demand is high, so water generally every 7-10 days, and stop watering 1 week before harvest.

4. Pest and disease control. The main pests and diseases include downy mildew, leaf blight, garlic maggot, and onion thrips. In early April, control garlic maggot by drenching the roots with 1000-fold 50% phoxim solution. After mid-April, strengthen control of diseases such as downy mildew and leaf blight. In the early stage of disease occurrence, promptly spray 600-fold 75% chlorothalonil wettable powder or 1500-fold 50% iprodione wettable powder, once every 7-10 days, for 3-4 consecutive sprays. At the same time, pay attention to damage by onion thrips; in the early stage of occurrence, spray 1500-fold 10% imidacloprid for control, for 2-3 consecutive sprays. During the growth period, if plants with deformed, shrunken, mosaic, or poorly developed leaves are found, they may be infected by viral disease and should be pulled out promptly.

5. Harvest. In the Jiaodong region, harvest is generally in early June. Harvest promptly when the tips of the lower 1-3 leaves turn yellow and dry, the upper leaves are grayish green with yellowing tips, and the pseudostem is slightly soft. Ensure that the garlic bulbs are wrapped by at least 3 layers of outer skin, so that cracked garlic or separated cloves are less likely to form. This gives better marketability and is beneficial for processing. Storage and transportation.