Lettuce(wo sun )

Lettuce method:

Raw materials for making lettuce:

Cooked winter bamboo shoots 400 grams, celery 100 grams.

Ingredients for making lettuce:

Refined salt, soy sauce, monosodium glutamate, clear soup, sesame oil, ginger powder.

Processing steps of lettuce:

(1) Cut the tip of the bamboo shoots into pieces, heat the celery in the boiling water until it is green. Drain the water, cut it into pieces, and put it into the basin. Then add monosodium glutamate and sesame oil and mix well.

Lettuce

Lettuce (scientific name: < ilactuca sativa L.var. angustana iris. < / I), also known as lettuce, is a variety of lettuce in the genus Lactuca of Compositae, which can form fleshy tender stems and is a biennial herb. Also known as stem lettuce, lettuce, asparagus, lettuce. Delivery period: January to April. Lettuce originated along the Mediterranean coast and was introduced to China in the 5th century.

The aboveground stems are edible. The skin of the stems is white green, the flesh of the stems is crisp and tender. It can be eaten raw, cold, fried, dried or pickled, and the tender leaves can also be eaten. The stem and leaf contained lactucacin (< ic11h14o4 < / I or < ic22h36o7 < / I). It tastes bitter and has analgesic effect. The adaptability of lettuce is strong, it can be cultivated in spring and autumn or overwintering, mainly in spring and harvested in summer.

(overview picture reference source:

）

morphological character

Lettuce is an annual or biennial herb, 25-100 cm high. The root extends vertically. Stem erect, solitary, upper panicle branched, all stem branches white. Basal leaf and lower stem leaf are large, undivided, oblanceolate, elliptic or elliptic oblanceolate, 6-15 cm long, 1.5-6.5 cm wide, apex acute, short acuminate or round, sessile, base heart-shaped or arrowhead shaped, half embracing stem, margin undulate or serrate, upward gradually smaller, isomorphic or lanceolate with basal leaf and lower stem leaf, panicle branches, lower leaves and panicle flowers The leaves on the branches are very small, ovate cordate, sessile, base cordate or arrowhead, margin entire, both sides of all leaves glabrous. The head shape inflorescence majority or extremely many, arranges the Panicle in the stem branch tip.

Involucre fruiting stage ovoid, 1.1 cm long, 6 mm wide; involucre 5-layered, outermost layer wide triangular, about 1 mm long, about 2 mm wide, outer layer triangular or lanceolate, 5-7 mm long, about 2 mm wide, middle layer lanceolate to ovate lanceolate, about 9 mm long, 2-3 mm wide, inner layer linear long elliptic, 1 cm long, about 2 mm wide, all involucre apex acute, without outer surface Hair. About 15 ligulate florets. Achene oblanceolate, 4 mm long, 1.3 mm wide, compressed, light brown, with 6-7 veinlets on each side, sharp tip, slender beak, slender filiform beak, about 4 mm long, as long as achene. Corolla 2-layered, slender, hispid. The flowering and fruiting period is from February to September.

Asparagus lettuce is a kind of taproot, and most lateral roots occur after transplantation, which are shallow and dense, mainly distributed in 20-30 cm soil layer. Stem shortened. Leaves alternate, lanceolate or oblong, pale green, green, dark green or purplish red, flat or wrinkled, entire or notched. The shortened stem gradually elongated and thickened with the growth of the plant. After the flower buds were differentiated at the end of the stem, the flower stem elongated and the stem thickened to form a rod-shaped fleshy tender stem. The flesh color is light green, emerald green or yellow green. There are about 20 flowers in each inflorescence. They are self pollinated and sometimes cross pollinated. Achene, dark brown or silvery white, with corolla.

Growth environment

Lettuce is sensitive to the acid-base reaction of soil and suitable for planting in slightly acidic soil.

The root system of lettuce is shallow, the absorption capacity is weak, and the requirement of oxygen is high. The best soil for planting lettuce is sandy loam and loam.

geographical distribution

It is cultivated and wild all over China. Lettuce is native to the Mediterranean coast.

Main varieties

According to the shape of lettuce leaves, it can be divided into two types: sharp leaves and round leaves. According to the color of stem, there are white shoots (green white skin), green shoots (light green skin) and purple shoots (purple green skin).

Lettuce with sharp leaves

Leaf blade is lanceolate, apex is sharp, leaf cluster is small, internode is sparse, leaf surface is smooth or slightly shrunk, color is green or purple. Fleshy stem rod-shaped, thick at the bottom and thin at the top. It can be cultivated in autumn or over winter. The main varieties are: LiuYe lettuce, Beijing ziye lettuce, Shaanxi Jianye Baishu, Chengdu Jianye, Chongqing wannianzhuang, Shanghai Jianye, Nanjing Baipi xiangzaozhong, etc.

Lettuce with round leaves

The leaves are long obovate, the top is slightly round, the leaf surface shrinks more, the leaf cluster is larger, the internodes are dense, the stem is thick (the middle and lower parts are thick, the two ends are gradually thin), the mature stage is early, the cold resistance is strong, the heat resistance is not strong, and it is often cultivated as winter spring lettuce. The main varieties are: Beijing crucian carp and melon, Chengdu guasihong, erbaipi and erqingpi, Jinan white lettuce, Shaanxi round leaf white lettuce, Shanghai small round leaf and big round leaf, Nanjing zipixiang, Hubei Xiaogan lettuce, Hunan luohammer lettuce, etc.

cultivation techniques

1. Variety selection

Winter asparagus lettuce and spring asparagus lettuce are cold resistant, adaptable and late bolting varieties, such as cold resistant white leaf tip, cold resistant two white skin, Ixeris sonchifolia, etc. For summer and autumn lettuce, early maturing varieties with heat resistance should be selected, such as heat-resistant white leaf tip, Ixeris sonchifolia, heat-resistant Dahua leaf, super heat-resistant erbaipi, youmaicai, etc.

2. Determination of sowing date

Spring lettuce was raised in plastic shed from December to March, and in open field from mid February to late March. Summer lettuce is cultivated in the open from April to the middle of May, and covered by shading net from the last ten days of May to July. Autumn lettuce was sown with shading net from July to September. Overwintering asparagus lettuce, October to November open field seedling.

3. Cultivate strong seedlings

3.1 soil preparation:

The plots with high and dry terrain and good drainage were selected as seedbeds, and 4000-5000 kg of decomposed organic fertilizer or 500 kg of compound fertilizer per mu were applied as base fertilizer 5-7 days before sowing. Before soil preparation, apply it, then turn it deeply, level it, cover it with plastic film and wait for sowing.

3.2 seed treatment:

The seeds sown in May to September are difficult to germinate due to hot and high temperature, so low temperature is needed to promote germination before sowing. Soak the seeds in cold water for 6-7 hours, then wrap them with wet cloth, and accelerate the germination at 20-25 ℃ until 80% of the seeds are white. Or soak the seeds in cold water for 1-2 hours, wrap them in wet cloth, place them in the well 30 cm above the water surface, drench them 1-2 times a day, and germinate in 3-4 days. Or soak the seeds for 24 hours, wrap them in wet cloth, put them in the refrigerator or freezer, freeze them in - 3 ~ - 5 ℃ for 24 hours, and then put them in a cool place, and germinate in 2-3 days.

3.3 sowing:

When spring lettuce is planted in the greenhouse, the film on the seedling bed should be uncovered first, and the bottom water should be poured. After the water seeps down, the seeds should be mixed in a small amount of fine sand or soil, and then spread. 10 square meters seedbed sowing seeds 25-30 grams. After sowing, cover soil 0.30-0.50cm, cover film tightly, and cover with sunshade net or straw at night for heat preservation. The seedlings were raised in open field and covered with small arch shed. Before the seedling is unearthed, the cover should be uncovered late and covered early, so as to improve the bed temperature without ventilation. After the seedlings were unearthed, the bed temperature should be maintained at 12-20 ℃ in the daytime and 5-8 ℃ at night with proper ventilation. The net should be uncovered early and covered late, 2-3 true leaves should be planted once, and the distance between seedlings should be 4-5cm. 5-6 days before transplanting, increase ventilation to refine seedlings.

Summer lettuce is sown on cloudy day. From April to the middle of May, the wet seeds were sown and covered with film, and removed after emergence. From the last ten days of May to the first ten days of July, the small arch shed or flat shed was used to cover the shading net until emergence or two true leaves. Cover with sunshade net to prevent rain water erosion in heavy rain days. 5-10 grams per 10 square meters. The distance between seedlings is 10 cm. Robust seedlings can also be planted in high density with a row spacing of about 10 cm. After thinning seedlings, setting seedlings and transplanting slow seedlings, combined with watering, apply rotten thin fecal water. In rainy days, the ditch should be cleaned and the water of 0.50% urea should be poured 15 days before planting. Young plants can be harvested and put on the market about 25 days after transplanting.

Before sowing autumn lettuce, the bed should be watered thoroughly. After sowing, the bed should be covered with a layer of 30-40% decomposed pig manure and a layer of thin straw, or covered with black shading net, and the germinated seeds or wet seeds should be sown. Before emergence, the double floating surface was covered on the seedbed soil, and the silver gray shading net was used for the back cover. Water and fertilize in the morning and evening, keep the bed soil moist, and weed and plant in time.

4. Planting and management

When planting, choose the loam with good drainage conditions, and apply 4000-5000 kg of decomposed organic fertilizer per mu. Deep turning and leveling, making 1.20-1.50 meters wide high border. Water the seedbed before lifting.

Spring lettuce, 25-30 days of seedling age, 5-6 leaves when planting, plant row spacing 20 cm × 27 cm, the depth of the first petiole buried in the base is appropriate, after planting, pouring water. It is listed on the market with leaves, and the row spacing is 15 cm × 20 cm. If the cultivation is covered with plastic film, the base fertilizer should be applied enough at one time, and the plastic film should be covered to drain and prevent waterlogging in rainy days. Greenhouse and open cultivation, choose sunny and warm weather tillage 1-2 times, timely watering and topdressing, early light manure frequently watering, keep the border moist, when the plant is basically closed ridge, can tender plant on the market. If the stem is used as the product, 15 kg urea per mu should be applied once or twice.

Autumn lettuce, 25 days of seedling age, planting, row

Chinese PinYin : Wo Sun