1, choose the good seed: after years of planting, lettuce varieties are more and more, for different regions and different climates and planting environment, developed a variety of different resistance varieties, if it is the spring planting then choose early maturity varieties, such as red lettuce and white lettuce.

But if it is summer and fall planting, you need to choose heat-resistant varieties, such as heat-resistant two white skin lettuce, there is also according to the local climate to choose the right varieties, because the variety of good and bad is the basis of the high and low yield.

2, the selection of land rectification: the choice of planting is the basic conditions of growth of lettuce, planting lettuce soil can not choose clay and heavy soil, because lettuce its absorption is relatively poor, if the soil is not able to grow, so it is best to choose the permeability of the soil, such as sandy or loamy soil can be.

The second thing is that the seedbed should be located in a high and well-drained area. The land should be y turned and leveled, the soil is fine, and the field has a good ditch, which is convenient for drainage.

3, timely sowing: different areas of lettuce planting time will have some differences, and the four seasons in various regions of China are relatively large, so the best sowing season is in the spring of March and April and fall of September or so sowing, because these time periods of the temperature is basically stabilized at about 25 degrees, and lettuce's growth cycle is probably about forty to forty-five days, the growth cycle of lettuce is about forty to forty-five days, the growth cycle is about forty to forty-five days. It can be harvested just before the onset of heat and frost, so yield and quality are not compromised.

We spread the seeds evenly on the seedbed, then cover the seeds with soil, cover a layer of livestock manure or rotting fertilizer on top, and finally cover a layer of plastic film, which can promote the germination of the seeds, and then you need to remove the film when the seedlings have grown two leaves, or they will be burned.

4, reasonable dense planting: wait until the lettuce seedlings grow six leaves or so, we can transplant, usually we will choose in the cloudy morning or after the rainfall transplantation, so that the survival rate of transplantation will be guaranteed. We plant according to the distance of thirty centimeters between each plant and forty centimeters between each row, a reasonable density can improve the yield of lettuce, but also in the later management is more convenient.

5, scientific management: field management is the most important is fertilizer, weed control and watering, lettuce growth we are mainly in order to let its stem growth, usually need to carry out three fertilizer. The first time is about ten days after planting, mainly using feces and urine water for watering, at the same time can be in the middle of a little urea. Secondly, we have to wait until the lettuce seedlings grow to about twenty-five centimeters to carry out the second fertilizer, mainly urea-based.

The last time is when the stem of lettuce swells, we are still urea-based, while spraying the right amount of potash, because if you don't fertilize, the lettuce flesh will be harder, affecting the quality of lettuce. There is also the need to combine every fertilization with watering and weeding, so that the lettuce can fully absorb nutrients and promote the growth of lettuce.

Expanded:

Disease Control of Lettuce

In addition to lettuce, the harm cabbage, cauliflower, radish, tomato, onion, carrot, celery, lettuce and so on. Leaves, stems or root crowns have wounds, easy to be invaded by the disease, began to appear translucent water stains, 2-3 days after the disease part of the color becomes darker, the epidermis is slightly sunken, overflowing white bacterial overflow droplets, the internal in addition to the vascular bundles are rotting in the form of sticky slippery soft rot, there is a foul smell.

High temperature, rainy, more insects, more wounds, heavy black rot and low-lying, early sowing, waterlogged plots of the field, the onset of serious.

Prevention methods:

1, agricultural measures to prevent and control: the selection of disease-resistant varieties, such as upright varieties of plants, the stem base of the water is easy to evaporate, the wound is easy to heal, can reduce the invasion of germs; it is advisable to choose the higher terrain, irrigation and drainage conditions, avoid the selection of low-lying and flooded plots: the implementation of crop rotation; the base of the fertilizer is fully rotted; shoveling out the diseased plants, the diseased holes disinfected with lime.

2, seed treatment: hot water and potassium permanganate soak seeds. Put the seeds in 50 degrees hot water for 25 minutes, then immersed in 1% potassium permanganate solution for 15 minutes, and then rinsed with water.

3, pharmaceutical prevention and control: the early stage of the disease with new phytomycin or agricultural streptomycin 1 catty to 4000 pounds of water, spraying or irrigation, can also be used in the biotin, vegetable fungicide 1 catty to 80-100 pounds of water to irrigate the roots. You can also use agricultural streptomycin one packet and green henry six one packet to 30 pounds of water to spray, or two packets of hydromycin and Chunrexin one packet to 200 pounds of water to spray.

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