The pollution-free and high-yield cultivation technology of lettuce in autumn and winter is introduced. In autumn and winter, lettuce production is relatively high, and the economic benefits are relatively good, and many places have launched large-scale planting, which has become an important source of income for local farmers.
Lettuce is divided into stem with lettuce and leaves with lettuce, we call the stem with lettuce is lettuce, grown in a light environment, belongs to semi-hardy plants, can not survive in a low temperature environment for a long time, at about 17 ~ 21 ° C when the assimilation effect begins, beyond this temperature, the assimilation will weaken, about 30 ° C, all the assimilated substances are used for respiratory consumption. Lettuce is planted in many southern regions of China such as Shanghai, Guangdong, Guangxi, Chongqing, Sichuan and other places. The cultivation of this vegetable has many advantages, such as short growth cycle, high temperature resistance, cold tolerance, strong adaptability, etc., individual places can be planted all year round, not only become one of the indispensable dishes in people's lives, but also increase the income of local people a lot of economic resources.
<h1 class="pgc-h-arrow-right" >1 environmentally sound choice</h1>
Lettuce has a strong viability, the soil requirements are not very harsh, planting pollution-free lettuce first of all, the local environment should meet the pollution-free requirements, soil, water, air should be certified by the Ministry of Agriculture. In order to be able to cultivate pollution-free high-yield and high-quality lettuce, strict requirements should be implemented for the living environment of lettuce. The root system of lettuce is relatively deep, generally 20 to 30 cm, and the lateral roots are relatively shallow and complex. The altitude of planting lettuce is generally more suitable at 400 ~ 600 m, the pH should be kept neutral, about 6 ~ 7, it is advisable to choose various types of soil with organic matter and minerals, the soil is more fertile, and the irrigation is more convenient.
<h1 class="pgc-h-arrow-right" >2 Select a good variety</h1>
At present, the varieties planted in shifang in autumn and winter mainly include black cow skin, bamboo tube green, green bamboo evergreen, green hanging silk, green crown, etc., these varieties have high temperature resistance, high humidity, cold tolerance, not easy to smoke moss, leaves oblong oval, green skin and green meat, meat crisp and tender, clear flavor, fast growth rate, high yield, resistance to storage and transportation, etc., the commodity value is extremely high, the weight of a single plant can reach 0.8 ~ 1.5 kg, the yield is 3 000 ~ 4 500 kg / 667 m2, under high-level cultivation conditions up to 5 000 kg / 667 m2.
<h1 class = "pgc-h-arrow-right" >3 breeding seedlings</h1>
<h1 class="pgc-h-arrow-right" >3.1 Seed treatment</h1>
First soak the seeds in water for about 5 h, then gently rub the seeds with your hands, wash the mucus impurities on the surface of the seeds 2 to 3 times, and then wrap them in a wet towel for germination. The appropriate temperature for the germination of lettuce seeds is 15 ~ 20 ° C, above 28 ° C germination is difficult, in the high temperature season, you can take the suspension of the deep well 10 cm from the water surface, check once a day, generally 2 to 3 d budding; can also be placed in the refrigerator in the preservation layer after 12 ~ 24 h, take out the cool and humid place 2 ~ 3 d powder nozzle can be sown.
< h1 class="pgc-h-arrow-right" >3.2 Sow at the right time</h1>
Autumn and winter lettuce sowing time in August to September is appropriate, according to different listing time can be flexibly adjusted, if the listing time is earlier, it can be appropriately advanced, and vice versa. When raising seedlings, the optimal seedling age should be mastered, generally 20 to 30 days after sowing, and the leaf age is the best at the 5 to 6 leaf stage.
<h1 class= "pgc-h-arrow-right" >3.3 Seedbed treatment and sowing</h1>
The seedbed land should be selected from fertile, sandy, not muddy, and organic matter-rich soil, so that the deep ditch is high, the width of the box is about 1.2 m, and the ground preparation is thin and thick. Combined with fertilization, fertilizer varieties are mainly organic fertilizers, supplemented by chemical fertilizers, generally every 66.7 m2 seedbed application of decomposed fine pig manure 150 ~ 200 kg, ammonium phosphate 2 ~ 3 kg spread in the box surface 10 cm deep seedbed topsoil layer, and combined with the application of "carbendazim", "ground insect clearing" to sterilize the soil sterilization, disinfection, insecticide. Mix the sprouted seeds with a certain amount of fine sand, sow them in separate compartments, and water through the bottom water. After sowing, the arch covers the shade net to prevent heavy rain and strong light exposure, reduce direct sunlight, which is conducive to budding, and pay attention to uncovering the cover in the morning and evening. When the seedlings grow to 3 to 4 leaves, set the seedlings, go to the small to stay large, to the weak to stay strong, to leave the disease to stay healthy plants, while appropriately applying seedling fertilizer, mainly to clear pig manure, with an appropriate amount of ammonium phosphate and urea, when the seedlings grow to about 6 leaves, with soil transplanting. The standards for strong seedlings are thick and short stem bases, tight and thick leaves, thick green leaves, developed roots, and no diseases and insect diseases and mechanical damage.
<h1 class= "pgc-h-arrow-right" >4 fertilization and colonization of fields</h1>
After the harvest of the former stubble crop, the weeds and dead branches and leaves in the field should be removed. Ploughing and drying soil, combined with the application of foot fertilizer, lettuce growth of nitrogen, phosphorus, potassium demand ratio of 1:0.5:1.5, generally every 667 m2 with decomposed organic fertilizer 2 000 kg, ternary compound fertilizer 30 ~ 50 kg, potassium sulfate 15 kg as the bottom fertilizer, nitrogen fertilizer accounted for 30% to 40% of the total fertilizer, while paying attention to the increase of phosphorus and potassium fertilizer, base fertilizer sprinkled on the field surface. After ploughing and rake flat, ditch the box, the width of the box is 3.3 to 4 m, so that the deep ditch is high, the transplanting and colonization specifications are 0.33 m×0.40 m, the planting should be shallow planting, and the root water is watered after planting.
<h1 class="pgc-h-arrow-right" >5 field management</h1>
<h1 class="pgc-h-arrow-right" > 5.1 fertilization</h1>
When the lettuce colonization is alive, the seedling fertilizer is applied in time, and the decomposed pig manure is added to the appropriate amount of urea or "flushing fertilization" to promote the development of the tree; "violent application of open fertilizer" promotes the opening of the lettuce on the plate; when the fleshy stem begins to expand, the moss fertilizer is applied, combined with the watering of the seedlings with urea 10 kg, potassium sulfate 15 to 20 kg, to promote the rapid growth of lettuce; suitable for the application of strong and sharp fertilizer, keeping the top and bottom consistent, and improving the yield quality. Eliminate the use of chlorine fertilizer 30 days before harvest to ensure the quality of the product.
<h1 class="pgc-h-arrow-right" > 5.2 irrigation</h1>
Autumn and winter lettuce in the water management to watering, irrigation as a supplement, in the continuous sunny and arid climatic conditions, can be appropriately flooded with horse water, with irrigation and drainage, keep the field soil moist, to avoid excessive humidity in the field, resulting in aggravated diseases.
<h1 class = "pgc-h-arrow-right" > 6 pest control</h1>
Autumn and winter lettuce diseases and insect pests mainly include downy mildew, seedling nuclear disease, gray mold disease, viral disease, aphids, spotted flies, beet nocturnal moths and so on. It mainly adopts the combination of agricultural prevention and chemical control, and in principle carries out prevention and control in accordance with the plant protection policy of "prevention first, comprehensive prevention". Downy mildew can be controlled by 70% ethylphosphate aluminum manganese zinc 800 to 1 000 times liquid, 40% dover 1 000 times liquid or 50% enoyl morpholine 1 000 to 1 500 times liquid control; sclerotia and gray mold can be controlled by 50% carbendazim 800 to 1 000 times liquid, 50% soxkrin 2 000 times liquid, viral diseases are mainly prevention, you can choose "viral spirit", "virus quick net" prevention, aphids, canetida flies can choose imidacloprid, 1.8% avermectin 2 000 times liquid control, Strictly abide by the safe use of drugs during the interval between applications, and advocate the use of yellow plates and frequent vibration insecticidal lamps to trap insecticides.
<h1 class="pgc-h-arrow-right" >7 summary</h1>
The promotion and use of pollution-free lettuce can promote the high yield of lettuce, and if there is a supporting research technology, lettuce can have a higher yield, which can drive the income level of local farmers. It is necessary to achieve timely sowing, accurate prevention and control, scientific management of water, etc., to maximize the yield level of lettuce.