How Are Solo Garlic Bulbs Formed? A Comprehensive Analysis of the Causes

Garlic is the collective term for plants of the genus Allium in the lily family (Liliaceae). It is flattened-spherical or short-conical in shape, with a grayish-white or light brown membranous skin on the outside. After peeling off the scale leaves, there are 6 to 10 cloves arranged in a ring around the flower stalk. However, sometimes after peeling it open there is only a single clove inside, and this is called single-clove garlic or solo garlic. Let us take a look below at how solo garlic is formed!

Cause One: Planting garlic too late is the main reason for producing solo garlic. If it is planted when spring is relatively warm, the garlic sprouts will soon encounter high temperatures and long daylight hours shortly after emerging. Under these conditions, many young buds will degenerate, leaving only a single clove.

Cause Two: Garlic produces a flower stalk that does not bloom but instead produces many aerial bulbils (formed by the enlargement of the flowers at the tip of the garlic scape). When these aerial bulbils are planted in the ground, the garlic that forms is often also single-clove garlic.

Cause Three: Early-maturing varieties, smaller cloves, poor soil, insufficient base fertilizer, drought and lack of water, severe weed competition, excessive density, too few leaves, and failure to meet the temperature and light conditions required for clove bud differentiation can all lead to the production of solo garlic.

Cause Four: Due to variety degeneration, garlic plants grow weakly, have a small leaf area, accumulate little assimilated nutrients, and the plant is unable to differentiate flower buds; these conditions can also produce single-clove garlic.

Solo Garlic Cultivation Techniques

1. Site selection and land preparation: For solo garlic cultivation, sandy soil or sandy loam should be chosen. After the previous crop is harvested, clean the field early, plow deeply and sun-dry, and mature the soil. Apply 2000 kg of decomposed high-quality organic fertilizer, 50 kg of superphosphate, and 10 kg of potassium sulfate per mu, then open beds at 1 to 1.2 m.

2. Clove treatment: Place the selected seed cloves in a low-temperature cold storage at 2 to 5 degrees C for 50 to 60 days. After cultivation, the proportion of solo garlic can reach 50%. Low-temperature-treated garlic seeds have already broken dormancy and begun to sprout, and their life activities are gradually strengthening, so they should be graded and sown as soon as possible.

3. Sowing time: Low-temperature-treated garlic seeds should be sown between the Autumn Equinox and Cold Dew. The solo garlic rate is 40 to 50%, and the solo garlic bulbs are large and of high quality with relatively high overall value, so the best sowing period for solo garlic cultivation should be during this period.

4. Pre-sowing treatment: Before sowing, first divide the low-temperature-treated garlic seeds into cloves and remove the bottom caps, then grade them into large, medium, and small for later use. Before sowing, soak them in cool clean water for 6 to 12 hours, drain off the moisture, treat the seeds with 50% carbendazim powder, and then sow.

5. Sowing methods

1) Dibbling: At a spacing of 4 × 5 cm between plants and rows, make holes in the bed surface with a wooden peg and place one garlic clove in each, with the root end facing down. After dibbling, cover the bed surface with 1 cm of fine soil. About 80,000 to 90,000 plants per mu.

2) Drilling: Use a hoe to make sowing furrows 4 to 6 cm deep and 15 cm wide, then sow the seeds in the furrows at a spacing of 4 × 7 cm between plants and rows. Be careful that the garlic cloves are not upside down. About 60,000 to 70,000 plants per mu.

6. Sowing depth: The sowing depth for solo garlic should be kept at 4 to 6 cm. On the one hand, seedling emergence consumes a certain amount of energy, which helps weaken plant growth and increase the solo garlic rate. On the other hand, the resulting solo garlic bulbs have a round and regular shape and good commercial appearance.

7. Intercropping: After sowing solo garlic, intercrop short-growing small leafy vegetables such as spinach, cilantro, and cherry radish. This can appropriately shade, compete for space, and compete for nutrients to inhibit seedling growth, thereby increasing the solo garlic rate.

8. Fertilizer and water management: Solo garlic requires different types of fertilizer sources at different growth stages. Overall, the early growth stage focuses on nitrogen fertilizer, while the later stage leans toward phosphorus and potassium fertilizers. On the basis of applying sufficient base fertilizer, timely topdressing is also required.

1) Seedling-promoting fertilizer: When solo garlic has grown 4 to 5 leaves, the nutrients in the seed cloves are nearly exhausted and the plant shifts to taking up nutrients from the soil. It should be promptly diluted and sprinkled with 1500 kg per mu of human and animal manure and urine, or topdressed with 5 to 10 kg per mu of urea along with watering and irrigation.

2) Bulb-expanding fertilizer: When solo garlic has grown 7 to 9 leaves, solo garlic bulbs that do not differentiate flower buds begin to expand, while clove garlic capable of bolting completes flower bud differentiation and elongates. Apply 12 to 20 kg per mu of potassium sulfate as topdressing and increase the amount of irrigation to promote rapid bulb expansion.

3) Foliar fertilizer: For solo garlic cultivation, appropriate concentrations of monopotassium phosphate, garlic-specific multi-element micro-fertilizer, and garlic bulb expansion agent should be sprayed on the leaves according to plant growth. These measures all help increase yield and quality.