Cultivation techniques of okra

Okra likes warmth, originates in India, and is widely cultivated in tropical and subtropical regions. The cultivation area of Hunan, Hubei, Guangdong and other provinces in China is also very wide. Known as the king of vegetables, it has high economic use and edible value.

I. cultivation season

Coffee sunflower likes warmth and is afraid of frost. the whole growth period should be arranged in the frost-free period, and the flowering and fruiting period should be in the warm and humid season. Cultivation in open field, sowing in April-June and harvest in July-October in the north and south of China. The seeds in North China are usually sown from mid-late April to May. Seedlings are raised in solar greenhouses and plastic greenhouses commonly used in cold areas in the north, and then planted in the field after frost in early spring and evening.

II. Land preparation and border formation

Coffee sunflower avoid continuous cropping, can not be mixed with fruits and vegetables, so as to avoid the occurrence of root-knot nematodes. It is best to choose root vegetables, leaf vegetables and so on as the previous stubble. The soil layer is deep, fertile and loose, and it is more suitable to conserve water and fertilizer. After harvest before winter, ploughing deeply in time, 75000 kg of rotten barnyard manure and 300kg of nitrogen, phosphorus and potassium compound fertilizer were applied per hectare. Open-field cultivation is often used in two ways: first, large and small rows of 70 cm, small rows of 45 cm, border width of 200 cm, 4 rows of each row, plant spacing of 40 cm; second, narrow ridge double-row planting, ridge width of 100 cm, two rows of each ridge, row spacing of 70 cm, plant spacing of 40 cm, furrow width of 50 cm. If planted in a single row at the edge of the field, roadside and riverside, the plant spacing is 60 cm, 3 plants per hole, ventilated and transparent, easy to manage.

III. Birth cycle

Germination period: sowing to 2 cotyledons flattening is the germination period, about 10-15 days. After sowing at 25-30 ℃ for 4-5 days, the soil can be germinated. It usually takes about 7 days for direct seeding seedlings to be unearthed in the open field, and plastic film mulching can emerge 2-4 days ahead of time.

Seedling stage: it takes about 40-45 days from 2 cotyledons to the first flower to bloom. After the general cotyledons fully expand, after 15-25 days, the first true leaf unfolds. After that, a true leaf occurs every 2-4 days, in which the first two true leaves are round. The growth is slow in the seedling stage, especially when the ground temperature is too low.

Flowering and fruiting period: from the beginning of flowering to the end of harvest, it takes about 85-120 days. It takes 50-55 days after emergence, and the first flower blossoms. The first and second flowers take a little longer from flowering to harvest. Later, with the increase of temperature, the harvest time shortened. It is usually harvested for the first time about 70 days after sowing. It can be harvested 4 days after flowering under the suitable temperature of 28-32 ℃ in day and 18-20 ℃ at night. Okra grows faster and grows stronger after flowering and fruiting, especially at high temperature. It spreads a true leaf every 3 days in July and 4-5 days in September.

IV. Field management

Between seedlings, when the heart is broken, it is the first time to go between seedlings, and between disabled and weak seedlings. When 2-3 true leaves are interspersed for the second time, strong seedlings are selected. The seedlings were fixed with 3-4 true leaves, and 1 plant was left in each hole.

After weeding and soil cultivation, the temperature is relatively low after the seedlings are unearthed or planted, so they should be ploughed twice in a row to increase the soil temperature and promote the slow seedling. The first flower should be ploughed before blooming in order to squat seedlings moderately to facilitate root development. After flowering and fruiting, the plant growth is accelerated. After each watering and topdressing, the plant should be intertilled, and the soil should be cultivated before closing ridges to prevent the plant from lodging. Summer rainstorm windy areas, it is best to choose about 1 meter bamboo pole, or branches inserted near the plant to prevent lodging.

IV. Watering and fertilization

Watering, coffee anemone requires higher air and soil moisture during growth. Artificial sprinkler irrigation should be done in the morning and evening when there is a shortage of water within 20 days after sowing. After the seedlings are slightly larger, mechanical sprinkler irrigation or furrow irrigation can be used. The summer season is in the peak harvest season of coffee sunflower, with large water demand and high surface temperature, so it should be watered before 9 o'clock in the morning and after sunset in the afternoon to avoid root damage under high temperature. Pay attention to drainage in the rainy season to prevent dead seedlings. The whole growing period is to keep the soil moist.

Topdressing, on the basis of sufficient base fertilizer, should be appropriate topdressing, not partial application of nitrogen fertilizer. The first time was Qi seedling fertilizer, which was carried out after emergence, applying urea 90-120 kg per hectare. The second time is to raise seedling fertilizer, fixed seedlings or planting after opening ditches to withdraw application, per hectare application of compound fertilizer 225-300 kg. Re-application of fertilizer during flowering and fruiting period, human feces dilute 30000-45000 kg, or nitrogen, phosphorus and potassium compound fertilizer 300,450kg. In the middle and later stage of growth, a small amount of topdressing should be applied for many times to prevent plant premature senescence.

5. Plant adjustment

Under normal conditions, coffee sunflower plants grow vigorously, the main and lateral branches are stout, the leaves are hypertrophic, and the flowering and fruiting are often delayed. Twisting branches can be adopted, that is, the petiole is twisted into a curved sag to control vegetative growth. In the middle and later stage of growth, the timely removal of the old leaves below the tender fruit can not only improve the ventilation and light transmission conditions, reduce nutrient consumption, but also prevent the spread of diseases and insect pests. Picking the heart of the young fruit harvester at the right time can promote the lateral branch fruit and increase the early yield. Picking the heart in time can promote the ripening of the fruit, make the grain full and improve the seed quality.