The method of accelerating germination of lettuce seed

Lettuce likes to be cold and cool, and the optimum temperature for seed germination is 15-20 ℃. If the temperature is above 30 ℃, it cannot be germinated. Autumn lettuce is sown in early autumn, when the temperature is high and it is difficult to germinate, so it is generally necessary to accelerate germination before sowing. Let's take a look at it.

Seed collection method of lettuce seed

For seed collection of lettuce, it is better to keep seeds of overwintering spring lettuce, and the isolation between varieties is about 1000 meters. The plants with strong growth and characteristics of this variety are selected. after intercropping, keep the row spacing of more than 33 cm square, remove the old leaves, increase fertilizer and water, cultivate soil, and promote the growth of lateral branches.

Properly remove some branches during flowering, insert pillars to prevent lodging, do not lack water during flowering, reduce irrigation after flowering, 20-25 days after flowering, the leaves of the seeds are normally yellowed, the seeds are brown or silver gray, and when they produce white crown hairs, they are harvested in time.

Treatment methods of lettuce seeds

Autumn lettuce is usually sown in July or early August, when it is hot and hot season, and the seeds are not easy to germinate. In production, low temperature treatment, hormone soaking and red light irradiation are often used to promote germination.

1. Low temperature treatment is the most commonly used method, that is, soaking the seeds for 24 hours, then placing the seeds in a bag in a cool place such as caves and wells, or directly in the refrigerator to keep the seeds below 25 ℃ and under moist conditions. After 3-4 days, the seeds can be sown when 80% of the seeds germinate.

2. Soaking the seeds with hormone can dry the seeds with 100 mg / L hormone for 3 minutes, and then sowing after washing, the germination rate of lettuce seeds under high temperature can be greatly improved. Treatment with 0.1% thiourea can also promote germination.

3. Irradiating lettuce seeds with red light can also promote germination at high temperature, but infrared light can inhibit germination.

Sowing time of lettuce seeds

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

2. Summer lettuce: cultivated in open field from April to the first and middle of May, covered with sunshade net from late May to July, direct seeded or planted with high density.

3. Autumn lettuce: sowing with sunshade net from July to September, raising seedlings and transplanting.

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