How to grow lettuce seedlings? A detailed guide to the key cultivation techniques
How to grow lettuce seedlings? Here is a detailed method. Lettuce seedling raising can be done by referring to the following methods: 1. Preparing the seedbed soil. Because cultivation seasons differ, there are two forms: open-field seedling raising and protected seedling raising. Seedlings can be raised by sowing directly in beds in the production field, or by using nutrient soil blocks, paper bags or nutrient pots...
How to grow lettuce seedlings? Here is a detailed methodLettuce seedling raising can be done by referring to the following methods:
1. Preparing the seedbed soil
Because cultivation seasons differ, there are two forms: open-field seedling raising and protected seedling raising. Seedlings can be raised by sowing directly in beds in the production field, or by using nutrient soil blocks, paper bags or nutrient pots. The seedling bed soil is 50% decomposed horse manure and 50% garden soil; at the same time, add 20 g of urea and 250 g of superphosphate per cubic meter of bed soil, mix well and sieve, then spread it evenly on the seedbed to a thickness of 5-10 cm.
2. Choosing lettuce seeds
Leaf-type lettuce includes head lettuce and loose-leaf lettuce, as well as semi-heading curly-leaf lettuce. In production, head lettuce is mostly used, such as the American Queen, Emperor and Great Lakes 659, and Japan's Olympia, etc., which are relatively heat-tolerant and have a shorter growth period.
3. Disinfecting and sprouting lettuce seeds
Lettuce seeds are small and germinate quickly, so dry seeds are generally sown directly. Seeds are usually only sun-dried for sterilization. If soaking seeds to sprout, first soak them in cool water for 5-6 hours, then place them under 16°C-18°C conditions with light to sprout; after 2-3 days they will sprout.
4. Lettuce should be sown at the right time
Lettuce can be produced year-round, so multiple batches of seedlings can be raised. Lettuce harvested in April-May can be sown and raised in February-March in spring.
For lettuce harvested in May-June, choose varieties that are heat-tolerant, disease-resistant and slow to bolt, generally sown in April.
For lettuce harvested in September-October, generally sow in June-July. For lettuce harvested in winter, generally sow in October. In winter it can be produced in a solar greenhouse, and can be planted after the previous crop is harvested and the bed is cleared. In the sowing and seedling bed, you can sow at any time, sowing one batch, planting one batch and harvesting one batch each month, so as to sow, plant and harvest simultaneously.
5. Standards for strong lettuce seedlings
Generally, protected seedling raising takes 30-50 days; the seedlings have 6-7 leaves, relatively many fibrous roots, dark green and relatively thick stems, large and wide leaves, a plant height of about 15 cm, and no pests, diseases or mechanical damage. For open-field direct sowing, the seedling age should preferably be 30 days, with 4-6 leaves.
6. Fine sowing method for lettuce
Before sowing, water the seedbed thoroughly; after the water seeps down, scatter a 0.5 cm layer of fine soil, and then sow. Generally, the sowing rate is 5-10 g per square meter. After sowing, cover with 0.5-0.8 cm of fine moist soil, maintain a soil temperature of 15°C-18°C, and cover with plastic film or straw curtains to keep moist; generally seedlings emerge after 3-5 days.
If raising seedlings in the open field, about 10 days after emergence (1-leaf stage), thinning can be carried out, to the extent that it does not affect seedling growth.
7. Lettuce seedling-stage management methods
At the 2-3 leaf stage of lettuce, transplanting can be carried out, with a seedling spacing of 6-8 cm, and 1 strong seedling per nutrient pot or paper bag. Water thoroughly before transplanting, cover with soil after planting, and keep the planting depth at the original level.
During the transplant recovery period, keep moist and warm, with an air temperature of about 20°C. After recovery, cultivate frequently to promote rooting, and prevent excessive humidity and the adverse effects of high temperature and rain in summer.
During the seedling stage, water lightly and frequently to keep the bed soil moist. For summer and autumn seedling raising, prevent rainstorm washing and high-temperature drought; rain-proof seedling raising and shade-net-covered seedling raising can be used. Generally, cover with a shade net from 8 am to 4 pm on sunny days, and uncover the net at night or all day on cloudy days.
In dry weather, water frequently in the morning and evening; fertilizer can be applied together with watering, generally applying dilute human manure 1-2 times, or spraying 0.3% potassium dihydrogen phosphate as a foliar fertilizer. About 30 days after sowing, the requirements for low temperature and short daylight should be met, which can prevent early bolting.
8. Precautions for lettuce seedling raising
Throughout the lettuce seedling period, prevent rodent damage and prevent thin, tall, spindly growth caused by high temperature and high humidity. Under dry and heavily fertilized or low-temperature conditions, the leaves are dark green and development is poor; under low-temperature and dry conditions, the hypocotyl is short and the cotyledons are small, resulting in stunted seedlings. Therefore, under general conditions, seedling hardening is not suitable. Sprouting should be carried out under cool, light conditions.
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