Introduction to biological characteristics and efficient planting methods of lettuce

Lettuce is one of the common vegetables in our daily life. It not only has practical value, but also has medicinal value. It can be used for heat-clearing and lipid-lowering. Because it contains a variety of vitamins, so its health effect is also good. Let's take a look at the biological characteristics and efficient planting methods of lettuce.

Biological characteristics of lettuce (planting conditions)

1. Climatic conditions

Lettuce likes the cool climate, and the lowest temperature for seed germination is 4 ℃ for a long time. The optimum temperature for germination was 15-20 ℃. After 3-4 days, the germination was blocked when the germination was over 30 ℃. Therefore, low temperature treatment should be carried out when sowing in summer to promote the activity of enzymes and the transformation of other substances in the seeds. The optimum temperature for stem and leaf growth of heading lettuce was 11-18 ℃, the optimum temperature for heading stage was 17-18 ℃, and the seedlings could tolerate-5 ℃. The low temperature above 21 ℃ is not easy to form the leaf ball or the internal temperature of the leaf ball is too high, which leads to the necrosis and decay of the heart leaf. When the temperature is above 30 ℃, the growth is poor. The temperature adaptation range of non-heading lettuce is wider than that of heading lettuce. For the sensitivity to sunlight, the early-maturing variety was the most sensitive, the middle-late-maturing variety was the second, and the late-maturing variety was slow to respond.

2. Water condition

Lettuce has different moisture requirements in different growth periods. Seedling stage can not be dry can not be too wet, too dry seedlings easy to aging, too wet seedlings easy to grow. In the budding stage, the moisture should be properly controlled, the moisture in the heading period should be sufficient, the water deficiency leaves are small, and the taste is bitter. Do not have too much water in the late stage of heading, so as not to crack the ball and lead to disease.

3. Soil conditions

Lettuce is suitable for slightly acidic soil, which is planted in soil rich in organic matter, with strong water and fertility conservation and high yield. for example, when planted in dry and water-deficient soil, the root system is underdeveloped, the growth is not full, the vegetable taste is slightly bitter and the quality is poor.

Introduction of efficient planting methods of lettuce

1. Variety selection and seasonal arrangement

Lettuce likes cold and cool. It grows best in the temperature range of 15 ℃ ~ 25 ℃ in winter and spring, grows slowly below 15 ℃, grows poorly above 30 ℃, and is easy to bolt and blossom. Hydroponic lettuce is suitable for loose leaf lettuce.

2. Preparation of nutrient solution and selection of cultivation containers.

The formula of nutrient solution is to add 600 grams of calcium nitrate, 600 grams of potassium nitrate, 350 grams of magnesium sulfate and 150 grams of ammonium dihydrogen phosphate per ton of water. In production, cultivation trough or cultivation pond can be used; in family cultivation, pots, bowls, boxes, etc., can be used to ensure that there is no leakage.

3. Seedling planting

(1) Seedling: take the seedling tray and use vermiculite as the seedling substrate, soak the vermiculite with water before sowing, spread the seeds evenly on the vermiculite, then cover a layer of vermiculite equal to twice the seed, pour through water, and the seedlings can emerge in 5-7 days at the temperature of 20 ℃. After emergence, the seedlings were irrigated with nutrient solution with EC value (the main index of water quality standard electrical conductivity) of 1.6-1.8.

(2) planting: take the foam board and punch a hole every 20 cm, with an aperture of 2.5 cm, and cover the mouth of the water culture container tightly. The nutrient solution was placed in the container with an EC value of 1.6 to 1.8. When the lettuce seedlings grew to 2 true leaves, the seedlings were divided and planted. First of all, wash the vermiculite from the root of the seedling, wrap the sponge strip in the stem base, and then stuff the seedling into the foam plate hole. Keeping the stem base dry and ventilated can greatly reduce the occurrence of rhizome base diseases.

4. Management and harvesting

The management process of hydroponic lettuce is very simple. In order to keep the liquid level of nutrient solution stable and consistent after planting, the nutrient solution can be added once every 2 to 3 days, the water temperature is 20 ℃ ~ 22 ℃ and the pH value is 6 ~ 6.5. When the seedling has 3 or 4 true leaves, the EC value is 1.8 / 2, and the nutrient solution is added according to the situation, which can grow into a commercial dish in about 20 ~ 25 days.

When cultivated at home, you can use the way of picking leaves, eat with picking, and keep fresh. Production is generally an one-time harvest. In order to directly show the characteristics of hydroponic vegetables, it is better to take part of the white root system. In order to reduce the content of nitrate in lettuce, there is no need to supplement nutrients, only water is added a week before harvest.