Detailed Explanation of High-Quality and High-Yield Cultivation Techniques for Jinshan Smoked Garlic

Jinshan Smoked Garlic is a local specialty of Kaiping City, Guangdong, and is a representative variety of garlic in central Guangdong. It is one of the main winter crops in the region and is sold in Southeast Asian countries, Hong Kong, China, Macao, China and the Pearl River Delta region. According to records, Jinshan Smoked Garlic has a history of more than 200 years, and is mainly cultivated in the areas of Shagang, Jinshan, Longtang, Changjiang, Shuikou, Siqian and Xinwu. Because the garlic heads are smoked after being dried in the field at harvest, the skin of the garlic heads turns brown-black, hence the name "smoked garlic." And because its production area is in the Jinshan area and it was exported in large quantities from Jinshan Wharf in the early days, it is called "Jinshan Smoked Garlic." Its main characteristics are: a short growth period, harvested about one month earlier than similar garlic heads; a thin stalk and large head, with thin scale leaves tinged with purplish red, and the base of the garlic head in a double-saddle shape; distinct cloves, plump flesh, and flesh that is pale yellow with white, with low moisture content after smoking, resistant to storage, and convenient for packaging and transport. The high-quality, high-yield cultivation techniques are summarized below.

1 Characteristics and Traits

The root system is shallow with few root hairs, but the roots are well developed and the plants are robust. Plant height is 50 cm, plant spread is 9 cm, pseudostem height is 28 cm with a thickness of 0.9 cm, and the whole plant has 15-16 leaves. The garlic skin exposes the cloves, and the garlic head is oblong-oval, with an average single-head weight of about 10 g. Each garlic head has 7-10 cloves, and the cloves are plump, with an average single-clove weight of about 1.5 g. The yield per 667 sq m is 750-1000 kg. The growth period is 140-150 days. It prefers cool conditions and fears warmth, is tolerant of fertilizer and resistant to disease, fears drought, fears waterlogging, and requires ventilation and light.

2 Cultivation Techniques

2.1 Sowing

In South China, it is suitable for open-field and plastic-film mulched cultivation in winter. Appropriate early planting is the key to high yield, around Frost's Descent, and no later than Minor Snow. In the Jinshan area, sowing is generally carried out in early October. On the one hand, bolting does not occur locally; on the other hand, the harvest period can avoid the rainy days of March. If sown early in hot weather (such as June-September), the garlic cloves must undergo seed soaking and low-temperature treatment to promote sprouting and rooting.

2.2 Raising Strong Seedlings

Select hard, round, plump, uniform, neat garlic heads free of pests and diseases as seed. Carry out graded sowing for ease of management. Mainly use dibbling, with a plant spacing of 8.5-10 cm and a row spacing of 16.5-20 cm. When sowing, point the garlic tip upward and insert the garlic base downward into the soil, with the depth such that the garlic tip is slightly exposed, and press appropriately so that the garlic cloves are in close contact with the soil, preventing the phenomenon of "jumping garlic" (cloves being pushed up and exposed above the ground). Use 60-70 kg of seed per 667 sq m. After sowing, cover with grass, using 7-8 loads of straw per 667 sq m (50 kg/load), densely cover the bed surface, then use bamboo poles to flatten and compact the grass surface to prevent sun exposure and heavy rain washing. At the same time, water thoroughly to settle the roots, which helps the seed garlic absorb water and swell, promoting germination and rooting.

2.3 Land Preparation and Fertilization

Choose sandy loam with good drainage and irrigation, deep soil layers, and rich organic matter. The previous crop is best if it is not an allium crop. Plow and sun-bleach, prepare the land, and make beds with furrows, with a bed surface width of 1.5-1.7 m, height of 25 cm, and furrow width of 30 cm. Level the bed surface and break up the soil. Apply sufficient base fertilizer before plowing, applying 2000 kg of decomposed barnyard manure or 75 kg of peanut cake or 40 kg of imported compound fertilizer per 667 sq m. If raw manure is used, it will burn the roots during fermentation and cause underground pests, especially severe occurrence of garlic maggots.

2.4 Field Management

After sowing, generally apply topdressing 3-4 times. The first topdressing is the seedling-promoting fertilizer at the 3-leaf stage, applying 15 kg of ammonium bicarbonate and 15 kg of phosphate fertilizer per 667 sq m to promote garlic seedling growth; subsequent topdressing depends on growth conditions and soil fertility. The second topdressing is the vigorous-growth fertilizer, to promote growth and make stems and leaves thick and strong, applying 5-6 kg of urea, 5 kg of potash fertilizer, or 7.5-10 kg of imported compound fertilizer, or decomposed livestock manure, manure ash, and farmyard manure, etc. per 667 sq m; the third is the bolting fertilizer, applying quick-acting nitrogen and potassium fertilizer, with 6-7.5 kg of urea, 7.5 kg of potash fertilizer, or 5-10 kg of nitrogen-potassium compound fertilizer; the fourth is the garlic head swelling fertilizer, mainly phosphorus and potassium fertilizer, and 400-500 kg of decomposed farmyard manure can be applied, while plots with poor growth can be supplemented with 7.5-10 kg of compound fertilizer to promote garlic head formation and growth. Fertilization should be carried out on sunny afternoons, and after each topdressing, water should be sprinkled, with sufficient water, to prevent leaf burn and root burn. Generally, no chemical nitrogen fertilizer is applied after Winter Solstice. In the middle and late growth stages, spray about 40 kg per 667 sq m on the leaves of one or more of 0.5% potassium dihydrogen phosphate, 0.5% borax, and 0.15% copper sulfate solution, and the yield-increasing effect is very significant.

Water requirements mainly depend on weather conditions and growth status. Field irrigation should not be too much. Generally, water is sprinkled once every 7-10 days to keep the field dry and the soil moist, avoiding water accumulation and waterlogging, and promoting growth. Stop watering 5 days before harvesting the garlic heads to control growth and promote the accelerated transport of assimilates from the leaves to the garlic heads.

Pay attention to removing field weeds, and promptly remove old leaves and yellow leaves. Herbicides can be sprayed from sowing to before emergence. During the seedling growth period of garlic, carry out intertillage and weeding as soon as weeds germinate, and pull out weeds between plants as early as possible to avoid competing with garlic seedlings for fertilizer.

2.5 Pest and Disease Control

The main problems are "one pest and two diseases," namely garlic maggot, leaf blight, and yellow spot disease. Prevention should be primary, with integrated control. In production, there are sometimes physiological abnormalities caused by cultivation techniques, such as secondary growth, bulb cracking and clove scattering, poor bolting, onion-like garlic, and collapsed seedlings. The most susceptible is "sitting-head disease." This disease starts with rotting leaves, the garlic seedlings do not grow, gradually shrink, and eventually the roots rot and the plant dies. Fertilizer and water management should be strengthened, such as increasing the application of farmyard manure and watering after fertilizing.

3 Harvesting and Seed Reservation

① Garlic head harvest period: 140-150 days after planting, or when only 2 true leaves remain, with leaf tips withered and drooping, or the leaf color still green but the leaf ends already withered and yellow and drooping, and the garlic heads have already broken roots, or when observing the underground part, the garlic heads are relatively large, with red skin, thin skin, distinct cloves, and plump flesh, then they can be harvested.

Generally harvest 1 batch every 3-5 days, harvesting in stages and batches. Harvest at noon and in the afternoon on sunny days when the plants are somewhat wilted and not easily broken. When pulling the plants, use appropriate force to avoid damaging the garlic heads. When trimming the roots, do not cut and damage the garlic cloves. After peeling the skin, grade them, tie them with straw, and cut the seedlings. The length of the garlic stalk (including the garlic head) should not exceed 26 cm.

② For seed reservation, the mixed selection method can be used. First carry out block selection in the field, and after harvest carry out individual selection, so as to reserve good high-yield and high-quality seed for garlic head production the following year. After harvesting garlic for seed use, it is best not to wash it with water or peel it. First dry it lightly in weak light or air-dry it in a dry, ventilated shade shed, then smoke it until the skin is brown-black to prevent insect damage. For stored smoked garlic, pay attention to checking for pests in June-July, and some insect-prevention chemicals can be sprayed, such as 50% phoxim emulsion or 80% trichlorfon crystal, etc. For seed reservation, generally choose garlic heads that are old-bodied, large-headed, thin-stemmed, with plump cloves, thin skin, small garlic heart, solid and round, and with bright and glossy skin and flesh.