What kinds of lettuce are there?
(1) classified by leaf shape.
Lettuce with sharp leaves. Leaf blade is lanceolate, also known as long tip. The higher the stem, the sharper the leaves, and the leaves tend to stand upright. The plant spread is small, the density can be slightly higher when planting, the fleshy stem is long and rod-shaped, and the bottom is thick and the top is thin. The internode (leaf distance) of different varieties is different.
Red-pointed lettuce is the main variety with thin internodes. The leaves are green and purple or even red and purple, such as China Hongyun, China Torch, Hongcui1; Red fairy is popular all over the world, and its base is booming. When it grows in the ground, it will give off fleshy stems. Generally cold-tolerant, suitable for autumn or winter cultivation.
Green pointed leaf is the main variety of lettuce with moderate internode density and smooth leaf surface. For example, Sanqing Jianfeng and Qingcui Jianfeng. Qing Xiang tip, fragrant green tip, etc. These varieties are generally heat-resistant and suitable for planting in late spring to autumn.
Lettuce with dense internodes at the tip is mainly heat-resistant varieties in late spring and early summer, with green leaves and slightly shriveled leaves, such as Xiangjian in summer and autumn, Baojian 1, Jinguan and so on. Shambhala, handsome and sharp leaves, a generation of tianjiao, etc. Suitable for planting in high temperature season.
B.lettuce with round leaves. The leaves are rectangular (inverted oval), and the wider the leaves are from the stem. The top of the leaf is slightly rounded. The surface of the blade is usually bubble-shaped, which is called wave contraction. Leaves tend to be semi-erect, and when they are harvested, the leaves unfold and fall, so the plants unfold more. It can be slightly thinner when planting. Those with strong heat resistance are cultivated in summer and autumn, and those with strong cold resistance are cultivated in late autumn. Or for lettuce cultivation in winter and spring. The internode density of different round leaf varieties is different.
Most high-temperature resistant varieties have moderate internode density, such as summer and autumn bamboo shoots, oriental charm, Shangri-La and so on.
Marshal, Bai Sheng II, Haoxiang Yuanye, etc. A lettuce variety with sparse internodes. Generally, it has strong cold tolerance and high yield. Lettuce stems are thick (thick in the middle and lower part and thin at both ends), such as Qingtianxia, Xiangshan Xue Fei, Zhonghua Baoding, Chun Qing and Wanshan Piaoxue.
The varieties with thin internodes are generally red round leaves, such as Dadihong, Hongcuizhu and Hongcui No.3: red sleeves add fragrance and red pavilions are the best in the world.
The rarest variety in internodes is naturally high-piled cold-resistant lettuce, such as Xiang Shuai Legend and Raymond. Gao Fushuai, Gao Hua and Wan Li are all fragrant. This variety has longer stems, more uniform thickness from top to bottom and thinner leaves. You can see round, slender and green fleshy stems in the field, which is very handsome.
② Classification by stem (leaf) color.
A. green and white lettuce. Leaves are green (shallow), stems are green and white, and meat is light green and white. Rudongbao No.1, Dongbao No.2 and Dongbao No.3; Shambhala, a generation of Tianjiao, Wanshanxiang, etc.
B. green lettuce leaves are green, stem skin is emerald green, and meat is emerald green. Such as Qingtianxia, Dadiqing and Zhonghua Qinglong. : Chun Qing, Qing Xiang, Trinidad, etc.
C. The front end of red lettuce leaves is green or purple, the stem skin is purple or purple, and the pulp is emerald green. Such as red emerald 1: red fairy, red crown world, red tea world, etc.
③ Classification by plant height.
A. high pile of lettuce.
Leading new varieties selected in recent years. Lettuce is more than 70 centimeters high when it is ripe and harvested. If the management is proper and the moderate and low temperature climate is well coordinated, the plant height of 120em is still not hollow, and the succulent stems can still be eaten. Such as the legend of Xiang Shuai and Qingtianzhu; , boutique, Cui, Wan Li incense, etc.
B. Non-heap lettuce. When the lettuce is ripe and harvested, the plant height is basically below 60em.
④ Classification according to temperature suitability (related to sowing date)
A. spring and autumn lettuce. Generally, it is planted in the open field in early spring and early autumn, and the optimum growth temperature is l0-25℃. Such as Jin Jian in China, fragrant flowers and green leaves; Cui Xiang Qingjian, Cui Xiang Yuqing, etc.
B. summer (autumn) lettuce. Generally planted in the open field from late autumn to early autumn, it can tolerate 35 degrees or even short-term high temperature. Rudongbao No.1 and Dongbao No.2; Shambhala, swordsman, Gao Xiang and other varieties.
C. overwintering lettuce Usually planted in the open field in autumn and winter. The optimum growth temperature is 0.20℃, and the varieties with strong cold tolerance can withstand short-term low temperature of about 3℃ in the open field. Such as green 1, green 2, green 3; One hundred million mu of evergreen, four incense counting, covered with snow.
Lettuce variety selection
At present, there are more and more large growers, vegetable professional cooperatives, planting companies, bases and other business entities. With the scale and intensification of production, the market risk of vegetable planting and management is also increasing simultaneously, so choosing the right variety has become the top priority for every grower. How to choose lettuce varieties, "Second Brother" thinks that the following personnel should be employed.
(1) To investigate the market, growing vegetables means selling vegetables, and selling vegetables is because people buy vegetables. At the beginning of the plan to plant lettuce, you should go to the local vegetable wholesale market to find out what kind of lettuce the market needs. Communicate with local vegetable buyers to find out where vegetables are trafficked and what varieties are trafficked; Search all kinds of supply and marketing information online. At least eight aspects need to be clarified.
1. Does the market need pointed leaf lettuce or round leaf lettuce?
The second is. Determine which places prefer green and white lettuce, which places prefer green lettuce and which places prefer red lettuce?
Third, red lettuce is becoming more and more popular on 20 16. Is it a red pointed leaf? Or red round leaves? Or it tastes different. Who are the buyers of these popular new products?
Fourth, do you need high-piled lettuce with long fleshy stems? Or do you need a shorter one?
Five is. Need varieties with thin internodes? Or a leafy variety with dense internodes?
Sixth, when will the listing price be high? Generally, the summer output is low or the listing price is high before and after major festivals, but it is not absolute.
Seventh, when will it be sold in large quantities? A boss once told Brother Long that he wanted to grow 66.7hm lettuce. What did he want to grow? Brother Long suggested to know the market first. It is best to divide 66.7hm into three batches and plant them at intervals of more than half a month to avoid selling vegetables.
Eighth, is lettuce digested in the nearest market or trafficked to other places over a long distance? Digest the varieties with thin seed coat nearby, and transport the varieties with thick seed coat long distance, because the thick skin is resistant to storage and transportation.
It is best to photograph the popular varieties and then go back to the lettuce seed supplier to buy them, so as to avoid the serious situation that lettuce is beautifully planted but no buyer can be found.
② planting time
Find out what varieties the market needs, then plan when to sell them, how long each variety will last in the local area, and then choose what varieties to plant.
There are four seasons in a year, and the seedling age of lettuce is different in different seasons, and the whole growth period is even different, and there are some differences among different varieties.
A. spring lettuce. Sow in June and March, the seedling age is 30-45 days, and harvest is 70- 100 days after transplanting.
B. lettuce in summer and autumn. Sow in April-August, the seedling age is 25-30 days, and harvest is 45-65 days after transplanting.
C. winter lettuce. Sow from mid-late August to early October of the following year (1), the seedling age is 30-45 days, and harvest is 70- 100 days after transplanting.
This is just a rough division. The temperature difference at different altitudes in the Yangtze River basin in the same season is obvious. For the specific whole growth period of lettuce in a certain area, it is suggested to know from lettuce seed suppliers or consult local experienced growers and agricultural technology departments.
③ Temperature and culture method
A. temperature environment. In the same season, different regions, different altitudes and different temperatures, we should choose varieties suitable for the temperature at that time. Plains, hills, mountains, light, warm water and soil are different, and the varieties used may be different. For example, during the high temperature period in summer, high-temperature resistant varieties must be planted in the plain areas of the middle and lower reaches of the Yangtze River. However, some alpine areas (800-l200m above sea level) can plant varieties with higher yield and high temperature resistance.
B. Training mode. Different cultivation methods, such as planting 4 rows, 6 rows or 8 rows per box, have fewer rows per box, the row spacing between plants can be slightly smaller, and the varieties with insufficient erect degree have little problem; The more rows, the larger the spacing between plants. Or choose a variety with a prominent erection. The purpose is to ventilate and reduce the occurrence of diseases.
It is said that "lettuce is as spring as gold", and lettuce is a "golden dish" recommended by nutrition doctors. Has the effects of diuresis, promoting lactation, strengthening body constitution, relaxing bowels, preventing cancer, resisting allergy, nourishing liver, protecting heart, resisting gout, activating insulin and promoting metabolism. Especially for children, eating more lettuce is very beneficial to their growth and development.
A year's plan starts with spring. Starting from spring, we should plant all kinds of lettuce, which is a good cause to enhance our health and improve our quality of life.