Growth habits and cultivation techniques of lettuce

Lettuce is also called goose lettuce, shipping mark lettuce, lettuce. For annual or biennial herbaceous crops can be eaten raw, crisp, tender and refreshing, slightly sweet. So let's take a look at the planting techniques of lettuce.

Growth habits of lettuce

Lettuce likes cold environment and is neither cold-resistant nor heat-tolerant. The suitable temperature for growth is 15 ℃-20 ℃ and the growth period is 90-100d. The seeds are tolerant to low temperature and can germinate at 4 ℃. The optimum temperature for germination was 18-22 ℃, and there was almost no germination when it was higher than 30 ℃.

During the period of plant growth, it likes cool climate, and 15-20 ℃ is the most suitable for growth, with high yield and good quality, and continuously higher than 25 ℃, with poor growth, thick and old leaves and slightly bitter taste. However, the cold tolerance is also quite strong, and 0 ℃ or even short-term subzero low temperature does not hinder the growth.

Lettuce has developed root system, waxy leaves and strong drought tolerance, but it has high yield and good quality when cultivated on fertile and humid soil.

The suitable pH value of soil is 5.8-6.6.

Cultivation techniques of lettuce

Selective sowing improved varieties

Choose suitable varieties according to your needs, such as glass lettuce, emperor, Caesar, heading lettuce, mosaic lettuce, Dahu 659 and so on.

Prepare the seedbed

The sandy loam with good water and fertilizer conservation and fertile soil should be selected for lettuce seedling raising. Bed and soil preparation: 10 square meters of seedling bed with rotten organic fertilizer 10 kg, ammonium sulfate 0.3 kg, calcium superphosphate 0.5 kg, potassium sulfate 0.2 kg, fully mixed evenly to lay Harrow fine, pour enough bottom water, sow seeds after water infiltration.

Sowing and raising seedlings

In order to sow evenly, the seeds can be mixed with a small amount of fine sandy soil, covered with 0.3-0.5 cm thick fluvo-aquic soil and covered with plastic film to moisturize. The sowing rate is 30-50 grams per mu. When the seedlings begin to be unearthed, the plastic film on the border should be opened in time to prevent overgrowth. The suitable temperature of seedling bed is 18 ℃-20 ℃ in daytime and 12 ℃-14 ℃ at night. Pay attention to ventilation and shade in case of strong light exposure. When the seedlings grow to 2-3 true leaves, divide the seedlings according to the row spacing of 6-8 cm, grow to 4-5 true leaves can be planted, the seedling stage is generally not lack of water. In order to prevent seedling diseases, spray 1-2 times 600 times 75% chlorothalonil.

Scientific fertilization

Lettuce requires clayey loam rich in organic matter and strong water and fertility conservation. Lettuce likes slight acidity and the soil pH value is 5-7. For every 1000 kg of lettuce, it is necessary to absorb 2.5kg of nitrogen, 1.2kg of phosphorus and 4.5kg of potassium. Among them, heading lettuce needs more potassium. Nitrogen, phosphorus and potassium fertilizers should be used together during the growing period. The land where lettuce is planted should be ploughed deeply and carefully, with sufficient basic fertilizer before planting, 3000-3500 kg per mu of rotten farm manure, turn deeply after application, pour enough bottom water, and make the bed after it is dry.

Careful planting

One day before planting, the seedling bed was irrigated to make the seedling moist, and the seedlings were raised with as much soil as possible the next day to reduce root damage. When planting, first open the ditch on the border surface, the ditch depth is 4-6 cm, plant 3 rows on the border surface of 70 cm, apply three-yuan compound fertilizer according to 25 kg per mu and then irrigate, after water infiltration, put the seedlings to cultivate the soil and seal the ditch according to the plant distance of 24 cm, rake the border surface, cover the plastic film, and introduce the seedling out of the film.

Post-planting management

Lettuce likes to be wet, and adequate water supply is required during the whole growth period. Slow seedling water was irrigated once after planting for 5-7 days. After watering the seedlings, the plots without plastic film were ploughed and loosened for two times to weed. After watering 3-4 times, combined with watering, nitrogen and phosphorus fertilizer was applied by stages, 15-20 kg per mu. Stop watering before harvest to facilitate storage and transportation.

Scientific harvesting

Non-heading lettuce can be harvested by camera according to market price. It is better for lettuce to be harvested after the bulb is tight, and the yield will be affected prematurely. If it is too late, the stem in the bulb will elongate and the quality of the bulb will decline.