What are the methods of lettuce seedling? Which is more efficient?

Lettuce is an edible vegetable with soft and fleshy stems. The taste is delicious and crispy, and it contains essential nutrients. Eating regularly can increase appetite, improve digestion, strengthen the body, and prevent cancer. In short, the benefits are many.

1.Sowing seeds and raising seedlings.

Autumn lettuce is generally transplanted by seedling transplanting, and germination at low temperature is required before sowing. After sowing, the seedbed should be kept moist. From seedling unwrapping to planting, 75% chlorothalonil wettable powder can be sprayed with 500 times of liquid every 7 10 days to prevent the occurrence of cataplexy and epidemic diseases.

In order to promote the growth of seedlings, seedlings should be applied potassium fertilizer 1 2 times at timely intervals.

2.Soil preparation and fertilization.

It is more appropriate to choose fields with fertile soil, good fertilizer and water retention, and convenient drainage and irrigation. Deep ploughing of the soil, 3500 kg of decomposed organic fertilizer, 50 kg of superphosphate and 50 kg of compound fertilizer per mu.

3.Colonize. When the seedling age is 25 to 30 days, and the true leaves grow to 4 or 5 pieces, they can be planted fixedly.

If the seedling age is too long, the seedling will easily "escape" if it grows too long. The planting row spacing is generally 30 35 cm, the plant spacing is 25 cm, and 6000 7000 plants are planted per mu. Planting times can be cloudy or after 4 p.m.

4.Tian Tuan management.

1) Watering. After planting, the roots should be watered immediately, and the thin manure should be watered once every two days after planting to promote slow growth of seedlings.

2) Fertilization. After slowing the seedlings, apply fast-acting nitrogen fertilizer, and then reduce watering appropriately to keep the soil moist. Before and after the rosette stage, heavy fertilizer 2 3 times, 3000 4000 kg of decomposing human and animal manure per mu, with a concentration of 30% 40%, or 15 kg of urea.

Homogeneous fertilizer and water to prevent stem cracking.

3) Culture. Fertilization, watering and rainfall after planting tend to cause compaction of the boundary soil. After sowing slow seedlings, it should be combined with fertilization and timely cultivation, which is conducive to squatting seedlings, promoting good development of root system, increasing rosette leaves, and healthy growth of young stems.

5.Prevent bolting.

In order to prevent the swelling of autumn lettuce, when the lettuce stem begins to swell, it can be sprayed with mequat 2 3 times on the foliar surface, which can effectively inhibit the stalk and increase the stem weight. In the late growth stage, the flower stems differentiated from the young stems can be removed, and the stems can be further grown.

6.Harvest. Autumn lettuce can be transplanted in batches and harvested one after another. After 45 days of planting, it can be marketed as a semi-mature plant, and the stems and leaves can be used. The harvest period is when the heart leaves are flush with the outer leaves or when the flower buds have just appeared, and they are classified as adults.

In summer and early autumn, when the temperature is high, seed germination is inhibited. Soak the seeds in warm water for 3 hours, then wrap them in a towel or gauze, place them in a well (20-30 cm above the water surface), remove them and drench them with cold water twice a day, or put them in a refrigerator freezer or fruit freezer for cryogenic treatment to promote germination.

Seedling raising methods include hanging well method, refrigeration method, irrigation and covering method, sand mixing method, generally according to the germination time to calculate the germination time of the sand mixing method is fast, more efficient.

Seedling cultivation method for lettuce planting.

1. Soaking seeds to promote germination: high temperature in summer and early autumn, seed germination is inhibited, you can first soak seeds in warm water for 3 hours, then wrap them in a towel or gauze, and place them in a well (20-30 cm from the water surface) Take out the cold water twice a day, and if possible, they can also be put into the refrigerator or fruit cold storage for low temperature treatment to promote germination.

2. Sowing and planting: live broadcast can be based on soil fertility, season, plant size, according to 25-30 cm plant spacing to hit the pond, first water the bottom of the water, put in 4-5 seeds, and then cover with fine fertilizer to keep the soil moist, 5-7 days to emerge. 2-3 leaves time seedlings 1-2 times, 4-5 leaves time seedlings.

Seedlings should be made a good seedbed, apply foot fertilizer, sow 80-100 grams of germinated seeds according to 20 square meters, cover centimeters of fine manure soil after sowing, and then cover a layer of straw or pine hair, and then water thoroughly with a watering can. After emergence, the mulch is gradually removed, and the seedlings can be planted when they are 10-15 cm and have 4-5 leaves.

1. Lettuce is generally planted in March and April in spring and September and October in autumn, that is, the temperature is about 25 degrees when planting is the most suitable, lettuce grows fast, 40 to 45 days can be harvested, before planting to cover a layer of rotted farmhouse fertilizer, and cover with film to promote planting germination.

2. Choose good varieties: There are many varieties of lettuce, and varieties with different resistance can be selected according to local conditions or seasons, such as red lettuce and white lettuce are suitable for planting in spring, and cold-tolerant varieties should be selected for autumn planting. Different varieties have a great impact on yield.

3. Land selection: do not choose clay and heavier soil for planting lettuce, the soil permeability is relatively poor, and it is very unfavorable for lettuce roots to absorb nutrients.

4. Reasonable dense planting: lettuce seedlings can be transplanted when they grow four or five true leaves, and the transplanting spacing is planted every 30 centimeters, and a reasonable density can enhance the photosynthesis of lettuce and improve nutrient accumulation.

5. Scientific management: in the process of lettuce growth, it is necessary to do a good job of fertilization, weeding, watering, etc., in order to ensure the yield, it is usually necessary to carry out three top dressing, the first time is about ten days after planting, mainly using manure and urine water for irrigation, and with nitrogen fertilizer, the second is when the lettuce grows to about 25 cm, mainly urea, and the third is when the lettuce stem is expanded, mainly nitrogen fertilizer, and with potassium fertilizer. Together, water and fertilizer allow lettuce to fully absorb nutrients.

Lettuce is divided into stem lettuce (lettuce) and leaf lettuce, and leaf lettuce has bulb lettuce and loose leaf lettuce. The minimum temperature for lettuce seed germination 4, but it takes a long time, the most suitable temperature is 15 20, only 3 4 days, the temperature reaches more than 30 germination is blocked. The seedling stage has a strong adaptability to temperature, the suitable temperature for growth is 12 20, and can tolerate the low temperature of -5 -6, but the temperature is too high, especially when the surface temperature is as high as 30, the seedling stem is susceptible to burn and fall seedlings, so the autumn lettuce should be shaded and cooled in the high temperature season.

Stem lettuce and bulb lettuce are generally transplanted with seedlings, while loose-leaved lettuce is often seeded or raised with hole trays. The sowing season of lettuce in major areas of China is shown in Table 3.

Table 3 Sowing dates of lettuce in different regions.

1. Choose the variety of lettuce.

When planting lettuce in spring and winter, you should choose lettuce that is cold-resistant, adaptable, and late-pumping, such as white-leaved, cold-tolerant, and cranberry; If you are planting in summer and autumn, choose early-maturing varieties that are heat-tolerant, such as cold-tolerant white-leaved fruit and heat-tolerant large-flowered leaves.

2. The time of lettuce planting.

Lettuce in spring, seedlings are raised in greenhouses from December to March, and in the open air from mid-February to late March; In the summer months (early to mid-May), it is planted in the open field, and from late to July, shade is required; In autumn, it is also necessary to shade the sun and transplant after seedlings; Lettuce is planted in winter, and seedlings are raised in the open field from October to November.

3. Soil fertilization.

Planted in soft, well-drained, rich organic matter, and strong water and fertilizer retention. To plough the sun, the fertilizer should be rotted farmhouse fertilizer, and the appropriate amount of fertilizer should be applied. After 7 to 10 days of drying, the ground is carefully prepared.

It is advisable to use rice for opening moisture, flat moisture for planting in the positive season, and high moisture (moisture of the soil in the field) for the reverse season.

4. Sowing seedlings.

Sowing seeds at the right time, you can sow the seeds directly; You can also use the new high-fat film to dress the seeds in advance, gently rake the surface soil with a tooth rake, let the seeds enter the soil, and then spray the new high-fat film 800 times on the surface of the soil to protect the seedlings. Pay attention to the prevention and control of soil compaction.

5. Seedlings. The seedbed should be watered frequently to maintain soil moisture (which is conducive to emergence). After the seedlings are gathered, attention should be paid to the timely thinning of seedlings, and the seedling growth caused by over-density seedlings should be prevented in time. It is also necessary to spray 800 times the new high lipid film in a timely manner.

6. Transplanting and colonization.

Transplanting should also be done in fertile, water-retaining soil. Before planting, a sufficient amount of bottom fertilizer should be applied and the bottom water should be watered thoroughly; The spacing of the plants should be appropriate, 20 to 26 cm square. After planting, it is necessary to water and fix the roots, and at the same time cooperate with the new high-fat film 800 times the solution.

First, select improved varieties and sow seeds at the right time.

To plant autumn lettuce, medium and late maturing varieties with high temperature resistance, not easy to sprout, high quality and high yield should be selected, such as Sichuan Erbaipi and Shanghai lettuce. Sowing seeds at the beginning of August, low temperature germination treatment must be carried out before sowing, that is, the seeds are packed in gauze bags and soaked in cold water for 5 6 hours, and the gauze bags are hung in the well 30 cm from the water surface or placed in the refrigerator refrigerator for germination, cleaned 1 2 times a day, about 3 5 days, 60% 70% of the seeds can be sown when they are white.

2. Shading seedlings and reasonable dense planting.

At the beginning of August, the temperature is high, and the seedlings must be shaded by the method: after sowing, the straw curtain and sunshade net are placed flat on the bed surface, and the curtain and the net frame are about 1 meter high after the seedlings emerge, so as to allow ventilation. Cover all day in the early stage of seedling; Cover at 9 a.m. and unveil at 4 p.m. on a sunny day in the middle of the day; In the later stage, it was gradually covered late and unveiled early to facilitate the refining of seedlings.

Seedlings are transplanted within 25-30 days after emergence. Because autumn lettuce grows under hot conditions, the plant size is generally not large, so the planting density per mu can be increased to 5500 6000 plants. After planting, it is best to use shade nets and other objects for overhead covering, and then gradually remove the cover after about 10 days.

3. Apply sufficient basal fertilizer and top dressing in time.

Choose a field with fertile soil to plant autumn lettuce. Before planting, 2500 3000 kg of human and livestock fertilizer and 35 40 kg of cake fertilizer were applied as base fertilizer. One week after planting, combined with cultivating and weeding, 150 kg of dilute manure water plus 5 kg of urea and potassium dihydrogen phosphate concentration per mu were watered.

Before the sealing of autumn lettuce, it was applied 2 3 times with dilute manure water and phosphorus fertilizer according to the seedling conditions.

4. Spray hormones to control pests and diseases.

In order to prevent the autumn lettuce from sprouting, it can be sprayed with a concentration of chlormequat liquid at the end of the rosette period, and sprayed again every 7 10 days. Topping when small buds are visible to the naked eye. In autumn, there is more rain, lettuce is prone to downy mildew, you can spray 90% ethyl phosphorus aluminum 500 times liquid or 75% chlorothalonil wettable powder 600 times liquid at the beginning of the disease, spray once every other week, a total of 3 4 times.

The main insect pests of autumn lettuce are aphids and red spiders. Aphids can be controlled with 50% Baofa No. 1 emulsifiable concentrate 1500 2000 times; Spider mites can be controlled with 1000 times of 20% dicofol EC.

1. Spring lettuce, greenhouse seedlings from December to March, and open-field seedlings from mid-February to late March.

2. Summer lettuce is cultivated in the open field from April to mid-May, covered with shade nets from late May to July, and planted in direct broadcast or high density.

3. Autumn lettuce, from July to September, use shade net to cover and sow seeds, and transplant seedlings.

4. Overwintering lettuce, seedlings in the open field from October to November.

Breed selection. 1. Overwintering lettuce and spring lettuce should be cold-resistant, adaptable, and late-sprouting, such as cold-resistant white leaf tips.

2. For summer and autumn lettuce, choose heat-resistant early-maturing varieties, such as heat-resistant white leaf tips, bitter wattle leaves, and heat-resistant large flowering leaves.

According to the practical experience and economic benefit analysis in Hanzhong in the past two years, the technology of multiple cropping of vegetables with artichoke, taro and lettuce three harvests a year is promising. In early December of each year, the artichoke is cultivated with mulch, harvested before May 1, taro seedlings are raised in mid-March, taro is planted after harvesting in early May, and lettuce seedlings are transplanted with soil after the taro is harvested in mid-August, and lettuce shoots are marketed in mid-October. 1. Artichoke cultivation technology points Artichoke is generally cultivated from early December to late January with plastic film mulching, and detoxified and high-yield artichoke species are selected, such as Kexin No. 1 or Kexin No. 6.

Deep ploughing and land preparation, generally 3,000 kg of farm fertilizer per mu, with 10 15 kg of ammonium carbonate and 15 kg of superphosphate, planted and fertilized according to a fixed distance, 8,000 plants per mu, harvested and listed before May 1. Second, taro cultivation technology points in mid-March taro seedlings planted, in early May after the harvest of artichoke, fine land preparation, application of foot fertilizer, planting taro, 6,000 plants per mu, harvested in mid-August. 3. Key points of lettuce cultivation technology 1. Seedling.

At the end of July, lettuce seedlings are raised, the variety is selected to be heat-resistant 200 skins, heat-resistant south wind No. 2, the seeds are soaked in warm water for 4 hours before sowing, the temperature of the water is 40, and the amount of seeds per mu is 150 grams, because the end of July is the high temperature weather, and lettuce can only sprout at low temperatures, so put two layers of bricks in a large basin, pour cold water, wait for the bricks to just expose the water surface, wrap the seeds with wet towels and put them on the bricks, so that the temperature drops. After two days, it will be ready to sprout. Make a meter-wide furrow in the nursery field, sprinkle the germinated seeds into the furrow surface, cover it with gray manure, and build a shade shed, and the seedling age is not more than 22 days.

2. Transplanting and post-management. Before planting lettuce in mid-August, 2,000 kg of high-quality soil manure was applied per mu and the land was deeply ploughed. Transplant bamboo shoots with soil, water the roots in time, combine cultivating and weeding, and strengthen watering management in the later stage to ensure sufficient soil moisture, planting 4500 seedlings per mu, and green shoots are listed in mid-October.