Pollution-Free Model High-Yield Cultivation Techniques for Garlic

Laiwu City, Shandong Province has long enjoyed the reputation of being the "home of the three spices." Its ginger, garlic, and other products are sold to many large and medium-sized cities domestically and to international markets, and garlic holds a pivotal and important position. For a long time, due to the irrational use of pesticides, chemical fertilizers, and other inputs, pesticide residues and heavy metal levels in garlic have exceeded standards, becoming a bottleneck for the sustainable development of the garlic industry. To this end, by summarizing the high-yield research, trials, and demonstrations on garlic in recent years, pollution-free model high-yield cultivation techniques for garlic are proposed.

1. Sowing at the appropriate time. Sow in late September, with a planting density of 20,000-24,000 plants per 667 sq m, a row spacing of 18 cm, and a plant spacing of 16-18 cm.

2. Land preparation and fertilization. Select fertile plots with deep soil layers, good irrigation conditions, flat terrain, loose plow layers, rich organic matter, strong fertilizer and water retention and drought resistance, and a pH value between 6.5 and 7.5, and that are far from cities, industrial and mining areas, and major traffic trunk lines, with no "three wastes" discharging enterprises nearby, a good farmland atmospheric environment, and irrigation water quality and soil environment that both comply with the "Environmental Quality Standard for the Production Area of Pollution-Free Agricultural Products." Deep plow and level, and harrow finely. Achieve a loose top and firm bottom, with a level surface. Mainly use organic decomposed barnyard manure, supplemented with bio-organic fertilizer, and broadcast it in combination with land preparation. Use 5000 kg of organic fertilizer, 100 kg of bio-organic compound fertilizer, and 40 kg of potassium sulfate per 667 sq m. After the fertilizer is applied, mix it thoroughly with the soil to prevent seedling burn. Before sowing, use 1.5-2 kg of 5% phoxim granules per 667 sq m, mix with 60 kg of fine soil, and broadcast along the rows. Or use 200 g of 50% phoxim emulsifiable concentrate, mix with 5-7 kg of water, spray and mix with 50-70 kg of sieved barnyard manure or dry fine soil, and apply it into the sowing furrow.

3. Selection of improved varieties and seed treatment. Mainly use Laiwu white-skin garlic. In garlic areas with continuous cropping, soak seeds with 50% carbendazim or 50% procymidone at 0.3% of the seed for 6 hours, then remove and sow. Or use 100-150 g of 50% procymidone wettable powder per 667 sq m, mix with 2 kg of water, spray and mix with 250 kg of garlic seed, then dry and plant. Or soak seeds in a 80-120 times dilution of Genkang for 30-50 minutes.

4. Management at the emergence stage. About 7 days after sowing, garlic enters the emergence stage. Artificially break the film in time and help seedlings emerge outside the film. The holes made by artificial film breaking should be small to ensure the film's heat and moisture retention. Depending on soil moisture, when seedlings emerge until 2 leaves and 1 heart, water once to promote seedlings. After Minor Snow, water once for overwintering according to weather changes. When garlic seedlings turn green in the following spring, water for turning green before the mother bulb recedes.

5. Management at the garlic bolt elongation stage. Strengthen fertilizer and water management. Spray 40 kg of biological fertilizer per 667 sq m, and water once every 5-6 days depending on weather conditions.

6. Management at the garlic bulb expansion stage. Do a good job of foliar fertilizer spraying and timely watering, fully utilize the functional role of leaves and roots at this stage, promote the transfer of stored nutrients to the bulb, and stop watering 5-7 days before harvest so that the garlic bulbs mature. To facilitate harvesting garlic bulbs, depending on moisture, water thoroughly 1-2 days before harvest to loosen the soil.

7. Integrated control of diseases, insects, and weeds. (1) Chemical weeding. After garlic sowing and before film mulching, select herbicides such as 40% Jiangsuan Caoke emulsifiable concentrate, dilute with water and spray according to the instructions, then cover with film. (2) Disease control. Use the biological pesticide 1% wuyi mycin for spraying before (or at the beginning of) disease occurrence to control gray mold. Use the biological pesticide 2% ningnanmycin for spraying before (or at the beginning of) disease occurrence to control viral disease. At the early stage of disease occurrence, use 50% Shibaogong wettable powder to control viral disease. (3) Insect control. In plots where seed flies occur, in combination with watering, use 0.75-1 kg of 50% phoxim emulsifiable concentrate per 667 sq m, prepare a 10-fold mother liquor, then apply it with water to control seed fly larvae. During the peak occurrence period of overwintering-generation seed fly adults, use 2.5% trichlorfon powder at 1.5 kg per 667 sq m, or use 2.5% deltamethrin emulsifiable concentrate at 30 ml per 667 sq m, diluted with 75 kg of water for spraying.

8. Timely harvest. (1) Garlic bolt harvest. Garlic bolts should be harvested promptly after growing, which can change the direction of nutrient transport in the plant, causing nutrients transported to the garlic bolts to turn toward the underground bulb and accelerating garlic bulb expansion. (2) Garlic bulb harvest. About 20 days after bolt harvesting, when garlic leaves turn grayish green, basal leaves wither and yellow, and the pseudostem becomes soft and fully expanded, it should be harvested in time. During the drying process after harvest, prevent rain exposure, and pay attention to moisture-proofing and heat-proofing to avoid blackening of the garlic skin.

9. Product safety control measures. (1) It is strictly prohibited to use highly toxic and high-residue pesticides in garlic production. Promote the use of biological pesticides and bio-organic compound fertilizers. (2) Strictly implement the pesticide application concentrations specified in national standards and the above techniques, and do not arbitrarily increase the use concentration (or dosage). (3) Strictly implement the pesticide safety interval. No insecticides may be used 10 days before garlic bolt harvest. (4) For seed fly control, apply pesticides as covertly as possible and reduce ground dusting and spraying. (5) Garlic should pass pesticide residue testing.