Detailed Explanation of Carrot Planting Methods and Key Technical Points

Biennial herb, 15-120 cm tall. Stem solitary, the whole plant covered with white coarse stiff hairs. Basal leaves thin and membranous, oblong; petiole 3-12 cm long; stem leaves nearly sessile, with leaf sheaths. Compound umbel, peduncle 10-55 cm long, with rough stiff hairs; involucre with numerous bracts, leaf-like, pinnately parted; numerous rays, the outer rays curving inward when in fruit; involucel bracts 5-7, linear; flowers usually white, sometimes tinged with pale red; pedicels unequal in length, 3-10 mm long. Fruit round-ovate, 3-4 mm long, 2 mm wide, with white bristles on the ribs. Flowering period May-July.

Planting Methods:

1. Site Selection and Land Preparation

Suitable land is very important for improving carrot yield. Carrots are suitable for planting in sandy loam soil with deep soil layers, loose texture and good drainage. The previous crop should be a plot that has not grown vegetables such as Chinese cabbage or radish, to reduce the chance of carrot disease infection. Because the carrot root system penetrates deep into the soil, if the soil is not loose enough, it easily leads to bent, short and small fleshy roots, and some may develop forked roots. Therefore, before sowing, the land should be deeply plowed, requiring deep plowing to reach 25 cm. While deep plowing, apply base fertilizer to increase soil fertility and provide sufficient nutrients for the entire growth period of carrots. The base fertilizer should preferably be organic fertilizer, combined with an appropriate amount of chemical fertilizer. The application rate is 3000 kg of organic fertilizer per mu (1 mu is approximately 667 sq m), 40-50 kg of potassium sulfate compound fertilizer, 50 kg of calcium magnesium phosphate fertilizer, and 25 kg of potassium sulfate. Organic fertilizer must be fully decomposed before use, otherwise it easily causes forked roots. After deep plowing and applying base fertilizer, form ridges. The furrow width is required to be 30-40 cm, the ridge surface width 60-70 cm, and the furrow depth 20 cm. The ridge surface requires fine, broken and level topsoil, which is beneficial for seedling emergence.

2. Variety Selection and Sowing

Select suitable varieties. The selected variety should have high yield, be resistant to bolting, have a long top cap, weak carrot top growth, cylindrical roots, be cold-resistant and drought-resistant, and have strong disease resistance. Carrot varieties should also be selected according to local climatic conditions and soil conditions. After selecting the variety, the seeds should be treated to improve the germination and emergence rate. Before sprouting, rub off the bristles on the seeds, then soak the seeds in warm water at 40°C for 2h. After drying, place them indoors at 20-25°C, cover with a wet burlap sack for sprouting. When most seeds are observed to have exposed radicles, they can be sown.

Sow at the right time. Suitable sowing time not only benefits seed germination and emergence, but also has an important effect on their growth and development and the later expansion of the fleshy roots. Carrot sowing is divided into spring sowing and autumn sowing. The best spring sowing time in Heilongjiang region is from late April to early May. For autumn sowing, choose to sow about 60 days before the average temperature reaches 21°C, generally in late July. If autumn sowing is too late, it will cause carrot growth to stop, resulting in low yield and light color, which adversely affects both yield and quality. Sowing methods include drilling and dibbling. Drilling requires a row spacing of 15-20 cm, and dibbling requires a row spacing of 15-20 cm X 14-16 cm. Cover the seeds with fine soil and press it firm with the foot, so that the seeds combine tightly with the soil, helping the seeds absorb water and nutrients from the soil and aiding emergence. Carry out reasonable close planting and determine the optimal sowing rate to ensure suitable density. Generally, the sowing rate is required to be 0. 7-1 kg per mu.

3. Field Management

Scientific and reasonable field management is the key work to ensure high and excellent carrot yield, and it cannot be neglected. Carrots generally emerge slowly, and some weeds will emerge earlier than the seedlings, which will affect carrot emergence. Therefore, on the day of sowing or the next day, spray herbicide to prevent weeds from growing densely. After sowing, water along the furrows to improve the emergence rate, and keep the soil moist while watering to prevent soil crusting, otherwise it will cause difficulty in emergence. During the period from sowing to emergence, about 15 days, keep the soil moist to facilitate seed germination and emergence.

When the seeds germinate and emerge and grow 1-2 true leaves, carry out thinning, pull out weak and small seedlings, and keep strong and large seedlings. After growing 4-5 true leaves, carry out final thinning, requiring the seedling spacing to be maintained at about 10 cm. For large varieties, the spacing can be maintained at 13-15 cm. Carry out reasonable close planting; too dense final thinning will affect yield. When 5-6 true leaves have grown, the soil requirement is relatively dry; such soil conditions are beneficial to root development. About 60-70 days after sowing and germination, carrots enter the rapid fleshy root expansion period. At this time, high-quality moist soil is required to promote root expansion.

4. Fertilization and Watering

After carrot emergence, remove the covering. In high-temperature and drought weather, water shortage easily affects normal seedling growth. It is necessary to sprinkle water (or irrigate in furrows) in the early morning or evening to moisten the soil and preserve moisture, keeping the soil at 70% of the maximum field water-holding capacity; at the 4-leaf stage, apply 15 kg of potassium sulfate compound fertilizer per mu along with watering. After about another 20 days, at the 7-8 leaf stage, apply 10 kg of potassium sulfate compound fertilizer and 5 kg of potassium sulfate per mu along with watering (water dilution ratio 1:100-200, i.e., 0.5-1% concentration); if the aboveground part grows too vigorously, apply only potassium sulfate, and at the same time spray paclobutrazol at a concentration of 100 mg/kg (100ppm) 1-2 times, with an interval of 10 days. In our area, September is a period of frequent typhoons. In case of heavy rain, open ditches in time for drainage to prevent water accumulation.

5. Pest and Disease Control

Strengthening carrot pest and disease control is the key to ensuring yield and quality. Common carrot diseases mainly include black spot, black rot and bacterial soft rot. The main pests include aphids, root maggots and underground pests. When preventing diseases, in addition to selecting suitable varieties, reasonable planting and crop rotation, field management should also be strengthened, with intertillage and weeding, and good preventive work. If disease is found during planting, targeted pesticides can be used for spraying control, but note that medication should be stopped half a month before harvest. For pest control, some pesticides can be selected for spraying control, combined with scientific field management.

6. Timely Harvest

Carry out timely harvest. Harvesting after the fleshy roots are fully expanded can increase yield. The optimal harvest period can be determined according to the growth period of the selected variety and soil and climatic conditions, and harvesting can be done in stages and batches. Harvesting too early or too late will affect the yield and quality of carrots. Well-harvested carrots should be stored under suitable environmental conditions.