The Latest Technical Method Tutorial for Growing Winter Lettuce in Greenhouses
Lettuce is a relatively common vegetable in our daily lives, and it has a fairly wide planting area in our country. Now, as cultivation technology becomes more and more mature, growing lettuce in greenhouses can basically be done all year round. And now, as the temperature gradually drops, how should greenhouse lettuce be grown in winter? Below, the editor brings you the cultivation techniques for greenhouse winter lettuce. Let's take a look!
1. Site Selection
The root system of lettuce is relatively weak, so its nutrient absorption capacity is not very strong either. Lettuce is not suitable for growing in a high-humidity environment. If it stays in a high-humidity environment for a long time, it is prone to downy mildew, sclerotinia and other diseases, which will have a great impact on the growth of lettuce. In addition, lettuce has relatively high oxygen requirements during growth. Therefore, the site for winter lettuce should be established on soil with high terrain, normal drainage and irrigation, and rich humus content. It is best to use sandy loam as the main soil type, and it must also be ensured that the soil has strong water and fertilizer retention.
2. Variety Selection
The selection of winter lettuce varieties is very important. Mid-to-late maturing varieties should be the main choice. If early maturing varieties are used, they are very prone to early bolting. Therefore, varieties such as Sanqingpi and Jinming No. 1 should be selected. Among them, the time from sowing to harvest for the Sanqingpi variety is generally about three months. Jinming No. 1 is a new variety in recent years, with strong resistance to sclerotinia, and its maturity period is generally about three months as well. A suitable variety directly determines whether lettuce can safely overwinter, and it is also the key to whether cultivation can succeed.
3. Timely Sowing
The planting time for winter lettuce is generally around September, and the average daily temperature must not be higher than 23 degrees. Before sowing, we should properly treat the seeds. First wrap the seeds in gauze, then soak them in clean water for about 5 hours. Then take the seeds out and place them in a refrigerated room to promote germination for about two days. After sowing, the temperature should be controlled at about 18 degrees. Pay attention to controlling the sowing density, with about 15 kg of seed used per mu. The sowing seedbed should mainly be vegetable garden land with sufficient fertility. Apply sufficient base fertilizer, then deep plow the soil, water it, cover it with soil, and then sow.
4. Seedling Stage Management
After sowing, there is no need to cover with soil; just gently scratch the surface soil. Then cover with a shade net for about three days, do a good job of shading, and keep the seedbed temperature at about 22 degrees. When the cotyledons of the seedlings are relatively plump, the shade net can be removed. After emergence, the daytime temperature should be controlled at about 20 degrees, and the day-night temperature difference should be maintained at 10 degrees. In addition, pesticides such as chlorothalonil should be sprayed appropriately to do a good job in preventing and controlling diseases and insect pests of the seedlings. Seedlings generally do not need topdressing. Keeping the leaf color of the seedlings on the lighter side is beneficial for slowing the seedlings after transplanting. However, attention should be paid to weeding to avoid weeds affecting the growth of the seedlings.
The above is a brief introduction to the cultivation techniques for greenhouse winter lettuce. That is all for today's introduction. This article is for reference only, and we hope it can help everyone!