Lettuce summer shade cover cultivation

First, choose a good variety

To cultivate lettuce in summer, we must choose heat-resistant, easy-to-fetch Caesar, Emperor, Xia Lu, Green Lake and other species. We must sow the seedlings between 3 and 4 in May and June.

Second, nurture strong seedlings

1. Soak germination. The seeds of lettuce are small, and it is difficult to grasp the live broadcast technology, and the uniformity of emergence is poor. Generally, seedlings are transferred. The nursery bed should be flattened, 25 grams per acre, and a seedbed area of 10 square meters. Soak germination before sowing. First soaked in fresh water at about 20°C for 4 to 6 hours. After the water is controlled, the seeds are wrapped in gauze and germinated at 15°C to 20°C. Can also be hung on the water surface of the well to germinate at low temperature, or placed in a refrigerator at 5 °C ~ 10 °C for 24 hours, and then put the seeds in the indoor cool place moisturizing and germination, until the seeds exposed white sowing.

2. Sowing seedlings. Before seeding, the seedbed is poured into the bottom water. After the water is infiltrated, the seed is mixed with the fine sand and sowed, covering 0.3 to 0.5 cm of sifting fines and covering the Shade Net or curtain. The general seedling age is about 25 days. During the seedling stage, the soil should be kept moist. The shade net should be removed when the young seedlings spit out their hearts, and the small water should be poured once to prevent the rushing out of the young roots of the seedlings. After watering, it is covered with a thin layer of fines. earth. When the two true leaves are set, the weeds are removed and the water is poured once. When the seedlings grow to 4 to 5 true leaves, they are planted in time.

Third, sorghum planting

Before the planting, combined with soil preparation and application of basal fertilizer, 2500 kg of organic manure per acre and 25 kg of superphosphate were used. In summer, small sorghum planting is generally used. The sorghum width is 70 cm. Two rows are planted in each row, and the plant spacing is 25 to 30 cm. Planting on sunny afternoons or cloudy days with planting of soil. The depth of colonization is best when the soil rake is flush with the surface of the mulberry. It cannot cover the heart and leaves. After planting, the seedlings should be poured in a timely manner and cover the shade net to reduce the ground temperature. The cover shade net must grasp the principles of daytime cover, night exposing, rainy cover, and cloudy exposing to create suitable growth temperature of lettuce and prevent rainwater from flushing.

Fourth, field management

1. Cultivator. 3 to 5 days after planting, timely tillage and protection, 1 to 2 times of shallow cultivating before mulching, in order to promote root premature.

2. Watering. During the growth period, the watering should be uniform, the small water should be poured, and the wet surface should be kept wet.

3. top dressing. Because raw lettuce is mainly eaten raw, top dressing is not applied to human waste or chicken manure, mainly chemical fertilizers, generally 3 to 4 times topdressing, 15 days after easing seedlings, head of the group regimen once, and the core period of time each time, each mu Application of urea 5 ~ 8 kg, with water flushing, but can not be used too much to prevent lettuce heartburn. During the growing season, potassium dihydrogen phosphate may be sprayed on the leaves to increase disease resistance and food quality.

4. Pest Control. Lettuce has very few pests and diseases, and only a few ticks can be used to prevent and cure pests with high efficiency and low toxicity.

V. Batch recovery

Due to the relatively high density of lettuce colonization, the staple foods are crisp and tender. Therefore, 30 days after planting, loose leaf ball can be harvested and listed.