Cultivation techniques of carrot in early spring. Variety selection
Carrots must be cultivated in greenhouse in early spring, and cultivated in the open field in spring out of season, with high yield, high quality, early maturity, strong cold resistance and bolting resistance. Generally, our city chooses five-inch varieties from Newton in Japan and Kuroda in South Korea.
Second, soil selection, soil preparation and fertilization
1. Soil selection. Choose loam or sandy loam with rich and deep soil, loose texture, high organic matter content and good drainage. If it is planted on clay, it is necessary to increase the amount of farm organic fertilizer, or apply a certain amount of plant ash when ploughing.
2. Soil preparation and fertilization. The ploughing depth should be controlled at 25 ~ 30 cm, preferably before winter; Before sowing, combine applying base fertilizer and ploughing again. Carrot fertilization should be based on base fertilizer, supplemented by topdressing. The amount of base fertilizer is 3000 ~ 4000 kg of fully decomposed farmyard manure per mu, and 50 kg of ternary compound fertilizer is applied. It is required to evenly apply the soil layer below 6 cm from the topsoil, and treat the soil with chemicals along with the soil preparation to prevent and control underground pests. Before sowing, the plowed soil should be carefully raked for 2 ~ 3 times, and then raked flat and dried. It is best to plant in a flat greenhouse in early spring, with the width of the border 1 ~ 1.5m, 5-8 rows per border and about 30,000 plants per mu.
Third, sowing date and sowing.
1. sowing date. At the end of February and the beginning of March, carrots can be planted in greenhouses in our city in early spring. Under the premise of selecting suitable varieties, early sowing can be listed as soon as possible.
Cultivation techniques of carrot in greenhouse in early spring
2. Sowing method and sowing amount. In qianzi, the sowing method of carrots in our city generally adopts direct seeding and drill seeding, the sowing amount per mu is 300-350g, and the precision machine sowing is about 200g. Press 18-20cm, ditch depth 1-2cm, cover the soil after sowing 1cm, and then compact the soil.
Fourth, on-site management
1. Management before and after first aid. The suitable germination temperature of carrot is 18 ~ 22℃, and the seedlings can grow completely about 15 ~ 20 days after sowing. When the seedlings grow completely, the film should be properly uncovered and ventilated during the day to prevent the seedlings from overgrowth or high temperature burning.
2. Intercropping weeding. Interplanting 3-4 seedlings for the first time at the true leaf stage, and removing weak seedlings, over-dense seedlings and deformed seedlings; Interplanting 5 ~ 6 pieces for the second time in the true leaf stage, and then fixing the seedlings. At the same time, weeds should be pulled out in combination with thinning seedlings.
3. Insulation and ventilation. In early spring, in March, when the outdoor temperature of greenhouse is low, intertillage should be used to keep moisture and keep warm. The surrounding plastic film should be uncovered later, and then gradually uncovered in the morning and evening, so as to extend the illumination time as much as possible and increase the daytime temperature. After entering April, the temperature rises rapidly, so it is necessary to strengthen ventilation to ensure that the temperature in the shed does not exceed 30℃. In late April and early spring, when the temperature outside the greenhouse rises steadily, it is necessary to remove the greenhouse film and let it grow in the open field in order to get enough light, accumulate more assimilated substances and promote the rapid expansion of fleshy roots.
4. intertillage and ridging. In the process of carrot growth, intertillage should be used to conserve soil moisture, which can be done at the right time after every thinning, seedling fixing and watering and fertilization. Because carrot fibrous roots are mainly distributed in 6 ~ 10 cm soil layer, intertillage should not be too deep. After intertillage, soil should be cultivated properly, and the fine soil should be cultivated to the roots for the last time to prevent the fleshy roots from turning green after being pushed out of the ground, forming green shoulders and reducing the quality.
Cultivation techniques of carrot in greenhouse in early spring
5. Fertilizer and water management. Carrot seedlings do not need much water and should not be watered too much. It is necessary to deeply hoe and squat seedlings, promote the extension of main roots and the development of fibrous roots, and inhibit the virtual length of leaves. When 3 ~ 4 seedlings have real leaves, cooperate with watering and apply potassium sulfate compound fertilizer15 kg per mu; When planting 5 ~ 6 real leaves, combined with watering, apply diammonium phosphate 15 kg and potassium sulfate compound fertilizer 3 ~ 4 kg per mu; At the 8-leaf stage, when the fleshy roots of carrots are obviously swollen, they should be fully watered to keep the soil moist. Combined with topdressing and watering, topdressing/kloc-0.5 kg diammonium phosphate and 5 kg potassium sulfate compound fertilizer per mu. Pay attention to uniform fertilizer and water to prevent root cracking. If the overground part grows excessively, spray paclobutrazol 1 ~ 2 times with a concentration of 20mg/kg, with an interval of 10 day.
Five, pest control
1. Underground pests: soil treatment is carried out in combination with soil preparation and fertilization, and 5-6 kg/mu of 3% phoxim granules are evenly spread; You can choose 5% trichlorfon powder or 5% carbaryl powder, 2 kg per mu, and infiltrate into the soil with tillage or water; Or use 80% dichlorvos emulsifiable concentrate 100g to prepare 15-20kg slag particles, sprinkle them on the ground, and immediately plough and harrow them. It is forbidden to use tert-butyl phosphate for soil treatment.
2, black rot: leaves are infected, forming dark brown spots, which seriously leads to leaf death. The lesion on the petiole is very long. The stems are mostly spindle-shaped to strip-shaped spots, and the edges of the lesions are not obvious. When the humidity is high, the surface is densely covered with black mold. Infected fleshy roots often form irregular or round slightly concave black spots at the root cap. In severe cases, the diseased spots spread to internal expansion, which turned the fleshy roots black and rotten. Prevention and control methods:
① Before sowing, seed is dressed with 50% thiram or 70% mancozeb which accounts for 0.3% of the seed weight.
② Spraying 600-fold solution of 75% chlorothalonil and 600-fold solution of 70% mancozeb at the initial stage of the disease, and controlling 1 time every 7 7- 10 days, 2-3 times in total.
3. Soft rot: it mainly damages underground fleshy roots, which can occur in the field or during storage. The stems and leaves in the field turn yellow and wilt, and the roots are wet first and then swollen. The shape of the lesion is uncertain and the edge is obvious or not. The fleshy roots are soft and grayish brown, and the rotten juice overflows and smells bad. Prevention and control methods:
(1) Strengthen inspection, drain water in time after the rain, and remove diseased plants at any time when found, and sprinkle lime or lime water for gonorrhea.
② Spraying 14% copper complex solution 300 times or 50% copper succinate (DT)500 times at the initial stage of the disease.
(3) Minimize the wound during harvesting, sun for half a day after harvesting, and strictly control the cellar temperature below IO℃ and relative humidity below 80% after entering the cellar, which can reduce the incidence.
Carrot cultivation techniques The growth cycle of carrot from sowing to seed maturity is two years, and 1 year is the vegetative growth period, and it grows into fleshy straight roots.
You can overwinter in the open air in the south and in the north.
Spend the vernalization stage at low temperature in winter. Sowing in the spring of the next year, bolting, flowering and fruiting, and completing the reproductive growth period.
The stage development of carrot belongs to the type of green vernalization, and the seedlings only accept the qualitative change of low temperature after reaching a certain size.
Therefore, it can be cultivated in summer, autumn and late spring, and spring sowing is too early. After the seedlings grow to a certain size, they will be pulled out in advance because of the long time of low temperature.
Carrots are usually sown in summer and autumn and harvested in autumn and winter.
According to the characteristics of high temperature in seedling stage and cool in root hypertrophy stage, and the climate of different regions and varieties, the sowing date is arranged so that the seedling stage is in the high temperature season and the root hypertrophy stage is in the cool season.
In order to supply fresh carrots in summer, early-maturing varieties can be sown in spring, and too long low temperature period should be avoided at seedling stage to prevent bolting in advance through vernalization period.
When the seedlings grow to 7-8 leaves, hoe and squat the seedlings when the soil is wet to promote the elongation of main roots and the development of fibrous roots and inhibit the excessive growth of leaves.
After 10 ~ 20 days, when the fleshy roots swell obviously, it is necessary to fully water and keep the soil moist frequently.
When planting 3 ~ 4 real leaves, 2 ~ 3kg of ammonium sulfate, 3 ~ 4kg of calcium superphosphate and 2 ~ 3kg of potassium fertilizer should be applied per mu.
When seedlings are fixed, each mu should be watered with diammonium phosphate 10 kg and potassium chloride 3 ~ 4 kg to promote the robust and rapid growth of seedlings.
When fleshy roots begin to grow, topdressing quick-acting organic liquid fertilizer or diammonium phosphate, potassium chloride, etc.
Harvesting spring carrots 90 ~ 100 days after sowing; Carrots in autumn are harvested and stored before the arrival of severe winter.