Technical Points of Lettuce Seedling Raising

The following are the specific precautions for lettuce seedlings that I will share with you today!

1. Choose a variety
Choose different lettuce varieties according to different crops. Greenhouse cultivation is generally dominated by head lettuce, and mid-to-late-maturing varieties with strong cold resistance can be selected.

2. Seed treatment
The seeds can be soaked in warm water at about 30°C for 2-3 hours first, and then put the seeds in a petri dish or gauze bag lined with wet filter paper, and put them in a refrigerator at 4-6°C for a day and night, and then they can be sown .

Dry seeds can also be used for sowing, and the seeds should be dressed with 75% chlorothalonil wettable powder equivalent to 0.5% of the seed weight before sowing, but it should not be left for too long.

3. Seedbed preparation
When the average air temperature is below 10°C, appropriate protective measures are required. Seedbed soil strives to be finely crushed and leveled. Apply 10-20 kg of decomposed farmyard manure, 0.05 kg of potassium dihydrogen phosphate, and 0.03 kg of superphosphate per square meter. Bottom water, after the water infiltrates, sprinkle a thin layer of sieved fine soil on the furrow surface, and then sprinkle the seeds.

For seedling transplanting, 25g of seeds are used per 666.7㎡. If peat and vermiculite can be used as substrates to raise seedlings in soilless plugs in greenhouses, it can reduce the occurrence of diseases and promote high-quality and high-yield.

4. Fine seeding
In order to sow evenly, mix the treated seeds with a small amount of fine-moist soil when sowing, mix well, and then spread evenly, and cover with a layer of 3-5 mm thick fine soil after sowing.

In winter, after sowing, cover the film to increase temperature and keep moisture; in summer, after sowing, cover with sunshade net or straw to keep moisture and cool down, so as to ensure that the seedlings are full and strong.

5. Seedling management
(1) The temperature of seedling age varies greatly in different seasons. Generally, seedlings are raised from April to September, and the age of seedlings is 25 to 30 days. Seedlings are raised from October to March of the next year, and the age of seedlings is 30 to 40 days.

(2) Temperature The temperature at the seedling stage is controlled at 16-20°C during the day and around 10°C at night.

(3) Separation of seedlings When there are 2 to 3 true leaves, the seedlings can be divided in two ways: nutrient pots and seedbeds. The nutrient pots can better protect the root system, and the seedlings can be slowed down after planting. Before the seedlings are divided, the seedbed is watered once, and the seedlings should be prepared, fertilized, and leveled as finely as the sowing beds, and transplanted to the seedlings to be planted in a 6-8 cm square; Cover the seedlings with mulch.

6. Colonization
After the seedlings are planted, the soil should be kept moist during the seedling slowing stage. Generally, the seedling slowing water is poured twice, and the amount of water each time will gradually increase with the growth of the seedlings. After slowing down the seedlings, properly control the fertilizer and water, which is conducive to rooting and strong seedlings.

7. Pest control
The disease that harms lettuce is mainly soft rot. In the early stage of the disease, 500 times liquid of 77% can kill wettable powder, or 5000 times liquid of 72% agricultural streptomycin soluble powder, or 500 times liquid of 70% mancozeb wettable powder Double liquid spray control, spray once every 7 to 10 days, and spray 2 to 3 times in a row.

Pests are mainly aphids, which can be controlled by spraying 20% methethrin or 50% pirimicarb (avoiding aphid mist) 2000-3000 times, or 10% imidacloprid 2000 times.

Edited by china microgreens growing tray supplier, propagation tray manufacturers.