Summer lettuce cultivation techniques
Although lettuce can be grown in all seasons, it can supply high-quality lettuce to the market during the off-season, and the economic benefits of planting will be very different. Farmers' friends can use heat-resistant varieties and corresponding cultivation techniques to plant and cultivate pollution-free lettuce in May-August, planting 4000-5000 plants per acre (using 30-50 grams of seed), with a yield of 2500-4000 kg, which will surely be achieved. Significant economic benefits.
Soil selection
Lettuce adapts widely, and the soil requirements are not strict. Generally, plains and slopes can be planted. However, in order to obtain higher benefits, it is necessary to choose fertile land that can be irrigated. For less fertile soil, a large amount of organic fertilizer should be added, and in a relatively dry field, mulch can be cultivated.
Variety selection
Choose heat-resistant, non-bolting moss, disease-resistant, high-yielding green-skinned green meat varieties, and choose to use sharp-leaved lettuce or round-leaved lettuce according to the consumption habits of local residents. Generally, the lettuce leaves are more heat-resistant and are not prone to illness. The lettuce is more easily accepted by consumers and the yield is higher.
Soaking seeds
Lettuce is a cold crop, which is not resistant to high temperature. The minimum temperature of seed germination is 4 °C, and the suitable temperature is 15-20 °C. If it exceeds 30 °C, germination is blocked, so it must be germinated at low temperature in summer. You can use the refrigerator germination or thermos flask with ice germination method. The specific method is to soak the seeds for 3-4 hours, then pick them up, put them into small cloth bags, dry the seed skin in the small cloth bag, mix them loosely, and put them in the refrigerator. Preservative layer. You can also put 1 or 2 pieces of ice in the thermos bottle, then hang the seeds in the bottle (be careful not to touch the water below), take out the seeds every 24 hours, rinse them with water, and bud them in about 48 hours. Or choose a cool location, such as a well, cellar, cave, etc., the temperature is maintained at about 20 °C, you can sprout in 24 hours.
Seedbed seedling
The seedbed is made 1 meter wide and 20 cm deep, and the length depends on the amount used. The surface of the carcass is fine, the surface of the car is drenched with water, smoothed with sand, and the mud is not dried. It is spread evenly according to 1 gram of seed (dry seed) of 1 square meter. A small arch shed is made on the side of the car, and the rain is covered with a film, and the sun is covered with a sunshade net. When the seedlings are out of the true leaves, they can be sprinkled with a spray pot with a mildew and avermectin aqueous solution. After 10 days of seeding, the seedlings were started, and the excess seedlings and weeds were manually removed, so that the distance between each of the two seedlings was not less than 3 cm. Generally, the seedlings of hot days should not be planted too much, and the seedling age of 15 to 25 days is appropriate.
Daejeon finishing
Fertilize. Fertilization mainly uses one-time application of base fertilizer. The amount of fertilizer per mu is 40 kg of urea, 50 kg of superphosphate, 30 kg of potassium sulfate, and 15 kg of monobasic phosphate. If the soil fertility is poor and the soil viscosity is high, it is also possible to apply 3000 kg of fully decomposed human and animal manure.
Pest and disease treatment. If it is a field where vegetables are grown all year round, it is recommended to use insecticides when plowing the land. Insecticides can be phoxim granules; bactericidal can be carbendazim or quicklime.
The whole car. After the fertilizer and the medicine are evenly applied to the field, the soil is rotated and the soil is required to be fine and flat. After ploughing, the car will be placed immediately, 2 meters open, the ditch is 25 cm deep, and the ditch is 25 cm wide.
Daejeon planting
Seed the seedlings on the seedbed with a loose hoe or a shovel and shovel together (usually shovel 3 cm thick) for transplanting. Choose cloudy or afternoon soil transplanting. When transplanting, use a knife to cut the clods, so that each seedling has more than 50 grams of mud (no mud block). 2 meters open, plant 5 rows, the nest is 35 cm. After planting, the surface of the seedling clods is parallel to the carcass. It cannot be planted too deep, and then the roots are poured.
Daejeon management
Cultivate weeding. Due to the rapid growth of summer lettuce, it is generally only cultivated once. The weeds can be pulled once in 20 days after transplanting.
Topdressing and hydrating. Summer lettuce can look at seedlings and topdressing. If the seedlings are in poor potential, they can use 20 tons of decomposed human and animal manure plus 20 kg of urea in the early stage, and topdressing 1 or 2 times. The remaining time can be poured 1 or 2 times. The lettuce cultivated in summer is small in size, and if there is too much rain, there is no need to water it; if the sun is large, the soil is dry and can be watered. Irrigation is best chosen at night. If the soil is heavy, it should be accompanied by irrigation. Do not let the ground have water.
Foliar topdressing. Due to the rapid growth of lettuce in summer and the short growth time (40 days after planting), the absorption of soil nutrients by roots alone is not enough. It is necessary to pay attention to foliar topdressing. For example, a nutrient solution in which one or more kinds of urea, potassium dihydrogen phosphate, amino acid, humic acid, glucose, and the like are mixed is administered every five days.
Pest control
The main pests and diseases of lettuce are: downy mildew, sclerotinia, soft rot, viral disease, mites, spotted fly and thrips. Downy mildew can be sprayed with 75% chlorothalonil 600 times or 25% metalaxyl WP 600-800 times solution; soft rot with streptomycin 150×10E-6～250×10E-6 or 50% dysen Ammonium 600 ~ 800 times liquid control; virus disease virus K400 ~ 500 times liquid; Sclerotinia sclerotiorum with 40% sclerotium net or 70% methyl thiophanate WP 1000 ~ 1500 times liquid control; aphids, spotted fly and The thrips can be controlled by chlorpyrifos, avermectin or 10% imidacloprid 1000-1500 times.
Timely harvest
Be sure to ban the use of pesticides 10 days before harvest. The harvest period of summer lettuce is also the most rapid period of bolting. If it is not harvested in time, the quality will become hard and even hollow after bolting. When the top of the main stem of lettuce is level with the tip of the highest leaf, it must be sold in about 3 days for the harvest.
Butterfly Pudding Powder,Blue Pigment,Butterfly Pea Flower Powder,Butterfly Pea Pollen
Shaanxi Zhongyi Kangjian Biotechnology Co.,Ltd , https://www.zyplantextract.com