Lettuce is divided into loose leaf lettuce, semi-knotted lettuce and knotted lettuce, the color has green leaves, white leaves, red leaves and purple leaf lettuce, which is an alkaline vegetable, which can be eaten directly without cooking, and the planting area is expanding year by year, often cultivated in courtyards, flower beds, roofs and balconies.
1. Cultivation season. Lettuce likes to grow under cold and cool environmental conditions, the suitable temperature is 15-20 ° C, and it grows well in the environment with a large temperature difference between day and night. In the northern region, most of the spring cultivation is the mainstay, north China and the Yangtze River Basin for spring and autumn cultivation, south China temperature is higher, autumn sowing from September, until February of the following year, before the end of April harvest. If lettuce is cultivated in greenhouses and in shade in summer, it is possible to supply lettuce all year round.
2. Variety selection. According to the basic conditions and cultivation seasons of various places, lettuce varieties with strong stress resistance, resistance to diseases and insect pests, wide adaptability and strong commercial performance are selected.
3. Seed germination. Sowing lettuce in the high temperature season is difficult to germinate and requires low temperature germination. Select the seeds, soak them in clean water for 6-7 hours, gently rub the seeds, wrap the seeds in gauze, place them in the refrigerator refrigerator for 24 hours, and then put them into the sweet potato cellar, cave or deep well 5-10 cm above the water layer to germinate.
4. Nursery land selection. Bulbous lettuce needs to be transplanted, and loose leaf lettuce is generally sown directly. A mixture of sieved pastoral soil and decomposed farmhouse manure is generally selected as the cultivation soil.
5. Sowing method. It is best to sow in strips, ditch at intervals of 15 cm, mix the seeds and fine sand well and spread them, the thickness of the cover soil is 0.5-1 cm, and 25-30 grams of seeds are needed per acre. When the temperature rises to 10 ° C in the spring, the seedlings can be started, and the seedlings can also be raised in advance with a small arch shed.
6. Nursery land management. In the high temperature season, the ground needs to be covered with straw and the air covered with shade nets for shading and cooling, and the low temperature season can be covered with mulch film or agricultural film to increase soil temperature. The use of small arch shed seedlings need to pay attention to windproof and refining seedlings, to prevent the growth of the seedbed, the temperature of the seedbed is controlled at 15-20 ° C is more appropriate. During this period, the soil moisture is controlled at the moisture level of the moisture to prevent the lack of seedlings caused by drought and the rotten seeds caused by stagnant water.
Divide the seedlings at 2-3 true leaves, water before the seedlings, transplant the seedlings to a nutrient bowl or other seedbed, the plant spacing is 5-8 cm, and water after planting to shade.
7. Field colonization. Lettuce seedlings grow to 5-6 true leaves when they are colonized, protect the root system as much as possible during colonization, water after planting, shade, and shorten the seedling period.