Detailed explanation of key points of high-yield and high-efficiency garlic cultivation techniques
Cangshan garlic is one of Shandong's famous local vegetables. Its bulbs are large, the skin is thin, and the cloves are white and neat, with a pungent and rich flavor. There are mainly 3 cultivars: Puke, Cao garlic, and Gaojiaozi. Among them, Puke has relatively strong growth vigor and adaptability, is relatively cold-tolerant, and has excellent quality, with characteristics such as aroma, pungency, and stickiness, and is relatively commonly planted. The cultivation techniques are introduced as follows:
1. Deep plowing and fine preparation, scientific fertilization. The garlic root system consists of string-like fibrous roots, which are relatively fragile and have poor vitality, with 80%-90% distributed within the 15-20 cm deep plowing layer. It prefers a fertile and loose soil environment, and loam soil is suitable. After the previous crop is harvested, plowing should be done promptly to conserve soil moisture, with a plowing depth of about 20 cm. After plowing, harrow finely and level in both directions, achieving a level surface and fine soil, with loose topsoil and firm subsoil, and no visible or hidden clods.
Garlic has a long growth period and requires a lot of fertilizer. The fertilization principle of "organic fertilizer as the main source, chemical fertilizer as a supplement; base fertilizer as the main source, topdressing as a supplement" should be followed. Generally, per 667 sq m, apply 5000 kg of farmyard manure, 100 kg of cake fertilizer, 75 kg of ammonium bicarbonate, 50 kg each of phosphorus and potassium fertilizers, 15 kg of diammonium phosphate, and 25 kg of garlic multi-element medium and trace element fertilizer. Note that farmyard manure, nitrogen fertilizer, phosphorus and potassium fertilizers, and trace element fertilizers should be broadcast and plowed into the soil layer. Cake fertilizer and diammonium phosphate can be used as seed fertilizer.
2. Timely sowing, improve quality
1. Carefully select seeds and sow by grade. According to the varietal characteristics, select garlic bulbs that are large, have large cloves, and uniform cloves as seeds. Before sowing, separate the cloves and grade them, and remove moldy, insect-damaged, and broken cloves. Generally, they are divided into 3 grades: large, medium, and small. When sowing, sow grade 1 seeds first (about 500 g per 100 cloves), then sow grade 2 seeds (about 400 g per 100 cloves). They should be planted separately, not mixed. Grade 3 cloves are generally not used as seed and can be used to produce garlic sprouts and blanched garlic leaves.
2. Timely sowing. According to many years of trials, the most suitable sowing period for Cangshan garlic is early October, that is, around Cold Dew. During this period, the average daily temperature is 16-17°C, and the soil temperature at a depth of 5 cm is about 18°C. After sowing, seedlings generally emerge in 8-10 days and are fully emerged in 13 days. Before winter, reaching 5 leaves and 1 heart indicates strong seedlings, with a well-developed root system and high resistance to chilling and freezing injury. In the following spring, they green up quickly and grow vigorously.
3. Scientific sowing. Sowing requires opening furrows about 10 cm deep, with a sowing depth of 6-7 cm. The depth, row spacing, and plant spacing should be uniform. At the same time, it should be oriented, planted straight, and planted firmly, that is, the belly and back of the garlic clove should be parallel to the row, so as to make full use of space and improve light energy utilization. After planting, level the soil, immediately water thoroughly, and settle the soil to promote the garlic cloves to take root and sprout. If watering is too little or too late, the seed cloves are easily pushed out of the soil surface by the root mass and are prone to freezing injury in winter.
4. Ensure suitable planting density. Adjust measures to local conditions and determine planting density according to factors such as sowing date, soil fertility, production conditions, and management level. Many years of trials show that the suitable planting density for Cangshan garlic is 35,000-45,000 plants per 667 sq m, with a row spacing of 18-21 cm and a plant spacing of 6-7.5 cm. The width of the bed should be determined according to irrigation conditions. For electric or mechanical irrigation, the bed width is 100-150 cm, with 5-8 rows planted per bed, and the bed ridges should be higher; for manual water lifting irrigation, the bed width is 60-80 cm, with 3-4 rows planted per bed.
3. Strengthen field management to ensure high and stable yield. The focus of field management is water and fertilizer regulation and integrated pest and disease control.
1. Management at sowing stage. At sowing, per 667 sq m, 100-150 g of 50% procymidone or 50% prochloraz can be added to 2 kg of water and evenly mixed with 200-250 kg of seeds. This prevents sclerotinia rot. After sowing, spray 800-fold dilution of 80% dichlorvos or 1500-fold dilution of 40% dimethoate emulsion 1-2 times to control onion maggots. Before emergence, water 2-3 times for emergence; after full emergence, water 2 times for seedling growth, and hoe and loosen the soil as appropriate to promote seedling growth and lay a foundation for overwintering. After "Minor Snow," water once for overwintering, and hoe and loosen the soil to conserve moisture, cover with some weeds to keep warm and protect the seedlings, and overwinter safely.
2. Management at green-up stage. In mid-February of the following year, that is, before "Awakening of Insects," the temperature rises and garlic seedlings resume green growth. Around Spring Equinox, remove the mulch, repair the bed ridges, and per 667 sq m, topdress 3000 kg of farmyard manure and 15 kg of potassium fertilizer or diammonium phosphate, apply them in furrows underground, then water, and hoe and loosen the soil as appropriate to eliminate weeds. To control root maggots, use 700-fold dilution of 40% isofenphos-methyl or 1500-fold dilution of 40% phoxim for root drenching.
3. Management during garlic bolt growth period. If no topdressing was applied earlier or if there is a fertilizer deficiency, per 667 sq m, topdress 15 kg of diammonium phosphate. After that, at each growth stage, water in installments to maintain a moist state in the field, and pay attention to hoeing and loosening the soil and pulling out weeds. From late March to early April, spray 80% dichlorvos or 40% dimethoate emulsion once every 7-10 days, for 2 consecutive sprays, to control onion maggots and aphids. From mid-April, use 1500-2000-fold dilution of 50% procymidone wettable powder for spraying to control garlic gray mold; use 500-fold dilution of 40% carbendazim or 600-fold dilution of 60% fosetyl-aluminum for spraying to control leaf blight, once every 7-10 days, generally for 2-3 consecutive treatments.
4. Management during garlic bulb enlargement period. After garlic bolts are removed, the growth of roots, stems, and leaves tends to decline, and garlic bulb growth enters the peak enlargement stage. After removing the bolts, water once accordingly, and water 2-3 times before harvest to maintain a moist soil surface, so as to meet the garlic's later water requirements, and spray once with a disease-control chemical (such as procymidone) to consolidate the disease-control effect and ensure a good garlic harvest.
4. Timely harvest. There are three standards for harvesting garlic bolts. First, the garlic bolt bends into a large hook shape, and there should be a 4-5 cm horizontal section above and below the bract (called "throwing the bolt"). Second, the bract is obviously swollen, and its color changes from green to yellow, then to white (called "white bract"). Third, 4-6 cm of the garlic bolt near the leaf sheath turns slightly yellow (called "throwing yellow"). Harvesting is generally ideal at noon and in the afternoon on sunny days. When removing the bolts, the main thing is to protect the garlic leaves, especially the flag leaf, and prevent the leaves from being lifted or broken, which would affect the enlargement and growth of the garlic bulb.
Most of the basal leaves of the garlic plant have dried up, and the upper leaves begin to fade, after which they gradually dry from the leaf tip toward the leaf blade. The plant is in a soft state. If the garlic stalk is forcefully pressed to one side down to the ground at a certain part and does not appear crisp but instead shows toughness, it indicates that the garlic bulb is already mature. When harvesting, pull gently and place gently, without knocking or bumping, so as to avoid damaging the garlic bulbs and reducing their commercial value and storability.