Leaf-free lettuce high-yielding cultivation techniques
Leaf lettuce is mainly eaten as a part of lettuce, and it is also known as lettuce because it is mainly eaten raw. Leaves with deep cracks, leaf shrinkage, adaptability, easy to cultivate. Excellent varieties include Guangzhou Dongshan lettuce (soft-tailed lettuce), glass lettuce, lettuce king, and the United States. First, nursery Lettuce (lettuce) is a semi-cold-resistant vegetable. It enjoys cool and humid climatic conditions. It is not resistant to heat. If it is to be used for annual sales, it can be produced by combining open field and protected land, which can basically meet the needs of the whole year. Normal seedlings use 25-30 grams per acre, and the ratio of seedbed area to colonization area is about 1:20. Lettuce seeds are small and germinate quickly, and dry seeds are generally used more often. Seeds are generally treated only with air. Such as soaking germination, first soaked with cold water for 5-6 hours, then placed under the condition of 16-18 °C see light germination. After 2-3 days sprouting. Seedlings can be sown on the field in the production field, and nutritious soil blocks, paper bags or nursery supplies can also be used. Lettuce is very adaptable to the soil. The nursery bed soil is preferably rich in organic matter, loose air permeability loam or clay loam, 50% fermented horse manure and 50% garden soil, and urea added per cubic meter of bed soil. Grams and superphosphate 200 grams, after sieving, mix well and spread 5 cm thick on the seedbed (10 cm thick for seedbeds). Before sowing, the seedbed is poured into the bottom water, and 0.5 cm thick fine soil is spread after the water is soaked. Generally, the seeding rate per square meter is 5-10 grams. After sowing, cover 0.5 centimeters of fine fluvo-aquic soil, keep the soil temperature at 15-18 DEG C., and cover the plastic film or straw to keep it warm. Generally, it can be excavated in 3-5 days. If the seedlings are planted in open field, about 10 days after emergence (1 leaf stage), the seedlings can be carried out so as not to affect the growth of seedlings. In the 2-3 leaf stage, it can be transplanted. The seedling spacing should be 6-8 cm. Seedlings and strains for each seedling. Bottom water before transplanting, soiling after planting, and planting seedlings should not be too deep. In the period of transplanting, seedlings should be kept warm and moist, and the temperature should be around 20°C. After easing the seedlings, it is necessary to reduce the humidity and cool the temperature, and the temperature drops to around 16°C. The key to this period is to promote the seedlings to be strong and not overwhelming. Winter and spring nursery seedlings should pay attention to maintain suitable temperature, use good lighting, easy to ventilate the greenhouse as a seedbed, proper control of watering, non-humidity is too large; summer and autumn open nursery, high temperatures unfavorable growth, need to be shade, rain, cooling Measures. Second, planting Seedling age 30-35 days, seedlings with 5-6 true leaves when planting. Before planting per acre, the quality of farmyard manure was 4,000 kg, compound fertilizer was 20 kg, and Pu Shi shallowly ploughed 15-20 centimeters, then made 1 meter wide rafts, and radon was 10-15 centimeters high. In autumn and winter seasons, in order to increase the ground temperature, the ground can be covered with film for 1 week in advance, and when the local temperature is stable above 8°C, planting can be achieved. Plant spacing 1720 cm, planting should be with soil mulch, planting depth to ignore the heart and leaves is appropriate, timely planting water. The temperature of facility cultivation is controlled at 12-22°C. In the hot season, colonization should be done in the morning on the day of planting, covering the shade net and transplanting in the evening. Third, field management Watering After the seedlings are transplanted, they can be topdressed with water. Leaf lettuce is extremely sensitive to soil moisture during growth, weak root absorption capacity, and large leaf area, so it consumes large amounts of water. The soil should be kept moist during cultivation, and it is usually watered for 5-7 days. When the temperature is low in spring, the amount of water should be small. Watering should not only ensure the plant's need for water, but also can not be excessive, and the humidity in the field should not be too large to prevent the occurrence of disease. 2. Weeding After planting and regenerating seedlings, we should carry out cultivating and weeding to increase soil permeability and promote root development. 3. Fertilization Need more nitrogen fertilizer and a certain amount of potash fertilizer, each mus can be topdressed with water 10 kg urea, 30 days before harvest to stop the application of available nitrogen fertilizer to prevent excessive accumulation of nitrate in the leaves. In addition, 0.2% potassium dihydrogen phosphate solution should also be sprayed on the leaves. 4. Temperature control Lettuce is not tolerant to high humidity. When the temperature exceeds 25°C, it should be ventilated, cooled or shaded. At the same time, lettuce is afraid of leeches, so there is no water in the urns and it must be drained in time after the rain. After the hot summer rains, it is necessary to use well water to feed the garden. The stems and leaves of lettuce are tender and juicy. When working in the field, care must be taken not to damage the stems and leaves or the roots, otherwise susceptible to disease. When the temperature is high and the soil moisture is high, when the dew is to be picked up, remove the yellow, old, and residual leaves near the ground to prevent infection. Fourth, harvest Leaf lettuce, its stems and leaves can be picked at any time before aging. However, the harvest period with the highest yield and the best value for the commodity is better when the leaves are fully grown and the green leaves are thick and tender. If the leaf ball is gently pressed by hand, there is a certain bearing force, and when the leaf ball is moderately tight, the harvest is best. Harvested late in the summer and autumn seasons, the buds within the ball are rapidly elongating and the leaf balls lose their value. For loose-leafed lettuces, leaflets can be picked and leaves can be picked, and the picked leaves can be placed on the market, and the whole plant can also be cut off. When the cabbage lettuce is harvested, it is cut off from the surface and the old leaves are removed. The outer leaves of the leaves are preserved in 3 to 4 outer leaves and can be packed and listed. Dried Wakame Stalks,Dried Wakame,Wakame Stem,Alga Wakame Shandong Haizhibao Ocean Science and Technology Co.,Ltd. , https://www.haizhibaoseafood.com