Detailed Explanation of Standardized Cultivation and Management Techniques for Carrots

The carrot, also known as red radish, clove radish, and hulu fujin, and also called hulufu, red beetroot, yellow radish, etc., is an umbelliferous biennial herbaceous plant, cultivated for its fleshy root, which is eaten as a vegetable. Every 100 grams of fresh carrot contains 1.67-12.1 mg of carotene, which is 5-7 times higher than that of tomatoes. After consumption, it is broken down into vitamin A through digestion in the stomach and intestines, and can prevent and treat night blindness and respiratory diseases. It can be stir-fried, boiled, eaten raw, pickled in sauce, salted, etc., and stores well. It is distributed throughout the world, and is cultivated in both northern and southern China, with output ranking second among root vegetables. It can fight cancer, and is known as the underground “little ginseng.”

Distribution

The carrot originated in western Asia. Afghanistan is the earliest cultivation site of purple carrots, with a cultivation history of more than 2000 years. In the 10th century, it was introduced to the European continent via Iran, where it evolved into a short conical orange-yellow form. By the 15th century, it was already cultivated in Britain, and in the 16th century it was introduced to the United States. In the 12th century, it was introduced to China via Iran, at which time the carrot developed into a long-rooted form in China. Japan introduced it from China in the 16th century, and there are distinctions between carrot and yellow carrot. The carrot is also called yellow radish, and Japanese people call it ginseng. The main production area of red radish “grassland ginseng” in China is Wusutu Township, Chahar Right Middle Banner, Ulanqab City, Inner Mongolia Autonomous Region.

Standardized Cultivation and Management Techniques for Carrots

I. Cultivating Mother Roots

1. Selection of seedling site: Choose sandy loam soil with a soil layer depth of more than 80 cm, high soil porosity, good permeability, convenient drainage and irrigation, and a pH value of 6.5 as the seedling site.

2. Land preparation and bed making, applying sufficient base fertilizer: The seedling land should be deep-plowed in spring, with 4000-5000 kg of decomposed organic fertilizer applied per mu, and 4 kg of borax applied to prevent brown spot disease. 4-5 days before sowing, make beds with a bed surface width of 1.8-2 m, a bed height of 10-15 cm, and a 30 cm small ditch left between beds. The bed surface is required to be fine, loose, flat, and soft.

3. Sowing and seedling raising: (1) Seedling land specifications: For carrot seed production, the male:female ratio is generally 2:6. When raising seedlings, this principle is also followed, with a plot area ratio of 2:6. Males and females are strictly separated, with a ridge added in between, and watering in separate furrows to prevent mixing of males and females. (2) Sowing: In mid-June, level and compact the seedbed, then evenly sow seeds in nutrient squares of 6×6 cm or 7×7 cm on the seedbed, with 2-3 seeds per hole, compact with a small wooden roller, and evenly cover with 0.5-0.8 cm of fine river sand on top.

4. Installing shade netting: After sowing, to maintain soil temperature, immediately cover the seedbed with black shade netting with a shading rate of 60%. The specific method is to plant a sturdy post every 3-4 m around the seedling bed, connect adjacent posts firmly with wire and rope at 80 cm above the ground, then prop up the shade netting and fix it on the wire or rope.

5. Irrigation after sowing: After sowing, because the outside temperature is high, water immediately, soaking the seedbed thoroughly, then water once every 3-4 days, for 3-4 consecutive times, and the seedlings will emerge.

6. Seedling stage management: (1) Thinning and intertillage weeding: When the seedlings grow to 1-2 true leaves, thin for the first time, then thin another 1-2 times, remove inferior seedlings and diseased plants, and remove all weeds in time during the growth period to promote carrot growth. (2) Reasonable irrigation: After sowing and emergence, depending on the dry and wet conditions of the seedbed, water once every 8-10 days. When the seedlings grow to 10 cm tall, water once every 15-20 days. During the peak leaf growth period of carrots, moisture should be properly controlled, with intertillage and seedling hardening carried out. When the mother root enlarges, irrigate promptly and sufficiently to prevent forking and roughness of the mother root.

II. Storage and Overwintering

1. Digging and cutting: From late October to early November, as carrot leaves turn yellow, dig them up promptly. Water 10-15 days before digging to reduce resistance during digging and reduce root damage. During digging, dig manually, dig lightly and shake heavily, and prevent roots from being broken by digging. Stack the dug carrots neatly. Cut off the leaves along the root head, leaving 3 cm of leaf top. Do not tear by hand, so as to avoid damaging the growing point. After cutting, eliminate hollow roots, multi-headed roots, cracked roots, mechanically damaged roots, and diseased roots, and prepare them for storage in the cellar.

2. Cellar storage for overwintering: Spread a layer of clean river sand 10 cm thick on the cellar bottom. Place the selected cut carrot roots with the root heads facing outward, 5-10 cm from the cellar wall, and tails leaning close to each other neatly in the cellar, stacking to a height of 60-80 cm. Fill the top with clean wet river sand, covering 10 cm thick, then cover with 10 cm of soil, which can prevent heating and freezing. In winter, regularly check the temperature inside the cellar and the moisture of the river sand to prevent cellar rot and freezing.

III. Planting Mother Roots

Mother roots that have safely overwintered can be taken out and planted directly in early April of the following year. They must not be taken out early, to prevent water loss.

1. Isolation setup: Carrots are cross-pollinated crops, and the pollination media are insects and wind. During production, attention must be paid to isolation between different varieties, and the isolation zone between varieties should be more than 2000 m away.

2. Land selection, deep plowing, land preparation and fertilization: For planting, choose wheat stubble or summer stubble land that is flat, convenient for drainage and irrigation, loose in soil texture, high in organic matter content, with good soil moisture, and good permeability. After deep plowing and ripening, apply 4000-5000 kg of organic fertilizer and 50 kg of diammonium phosphate per mu in combination with autumn deep plowing, then harrow and level.

3. Soil treatment. Ridging and film mulching: In early April of the second year, select 40% methyl isofenphos powder mixed with fine sand and broadcast it on the ground for soil insecticide treatment, then form ridges at a male:female ratio of 2:6 with a ridge height of 10-15 cm, that is, form one male row ridge, level the ridge surface, cover with 70 cm plastic film, with a film surface of 50 cm, at 1 cm intervals (some varieties are relatively short, and when forming ridges, an 80 cm interval from the female ridge is sufficient), then continuously form 3 female rows, with a ridge surface of 40 cm, a ridge ditch of 40 cm, and after the ridge surface is smoothed and leveled, cover with film.

4. Treatment of mother roots at planting: Before planting, take out the mother roots, prepare a medicinal solution with thiophanate-methyl or carbendazim, soak the mother roots in it for 10-15 minutes, then soak with methyl isofenphos solution for 10 minutes, and plant after taking them out.

IV. Field Management After Planting

1. Timely irrigation: After planting the mother roots, irrigate promptly to help seedling recovery. Throughout the growth period, maintain field water-holding capacity above 70%-80% to prevent drought and water shortage and death of mother roots.

2. Intertillage weeding, removing impurities and inferior plants: There are many weeds in carrot fields. After planting, promptly carry out intertillage and weeding in combination with each watering to promote mother root growth and facilitate bolting. For weeds that break through the film and emerge, after manual pulling, press the film holes tightly with wet soil. After bolting, remove plants with obviously inconsistent plant type and leaf color in the field, as well as diseased plants.

3. Pest and disease control: After planting, with each irrigation, flush in 39110.5 kg per mu for pest control. In severe cases, root irrigation can be carried out. If black wilt disease or black spot disease occurs during the growth period, use carbendazim for control, and combine with spraying 0.2% potassium dihydrogen phosphate as foliar topdressing. Never spray insecticides during full bloom, to prevent killing insects and affecting pollination.

4. Earthing up and pressing film in high-temperature season: From mid-June to early July, use 1 cm thick fine soil to press down the entire film surface, reducing direct sunlight and lowering the temperature inside the film.

5. Setting up supports: Carrot plants are relatively tall. In order to strictly prevent males and females from lodging and mixing with each other, set up firm and sturdy supports, prop up the females, and keep each growing independently.

6. Field cleaning: In carrot seed production, males are fertile plants and females are male-sterile plants. During the flowering period, strictly inspect the female flower disks. If there are plants shedding pollen, they should be thoroughly removed to prevent mixing into the seed of hybrid plants.

V. Harvest

After pollination ends, promptly remove the males from July 25 to August 1. In August, every morning with dew, select flower disks that have clearly reached nine-tenths maturity, cut them off, bring them back to the drying yard, rub them off promptly, dry them in the sun, select them clean, and store them in the warehouse after quality inspection. When harvesting, note that the seeds from small flower disks on secondary and tertiary branches that set seed later are mostly small and not plump, and must not be mixed with seeds harvested earlier, so as to avoid reducing quality.