What is the indoor soilless culture technology of watercress?

Watercress is called watercress, also called watercress, watercress and mustard. It is a cruciferous vegetable and watercress is a perennial aquatic herb watercress. 20-40 cm high, stolon, multi-branched, rooting at nodes; The leaves are odd pinnate compound leaves; Leaflets 1-4 pairs, ovoid or broadly ovoid, terminal leaflets entire or with some wavy teeth. Racemes are terminal, with white flowers and usually recurved pedicels. The watercress is light green, and the white one is the best. It is called "White Bone Douban", which originated in Europe or northern Asia and has been introduced to China for a hundred years. The modern giant Chinese medicine dictionary has income.

The origin of the name watercress is said to be that in the late 1930s, a Portuguese sailor suffered from lung disease. People thought he was dead, but he survived because he ate an extra portion of vegetables to satisfy his hunger. Portuguese living in Macau brought a small amount of this vegetable seed from abroad for a China woman to grow. After planting, it is fragrant and refreshing, which is very popular with everyone. It was introduced everywhere, so the planting area continued to expand. In just a few years, it was planted in Guangdong, Guangxi, Shanghai, Fujian, Yunnan, Sichuan and other provinces. In the mid-1980s, with the continuous expansion of foreign exchanges, some star-rated hotels and restaurants requested to launch a number of special dishes, and some large and medium-sized cities such as Beijing, Qingdao and Dalian also launched them one after another.

Watercress is rich in nutrition and has strong health care function. Modern research shows that watercress is rich in vitamin A, vitamin C and vitamin D, and pharmacological research shows that watercress water extract can inhibit the growth of Escherichia coli. According to the Handbook of Chinese Herbal Medicine published in modern times, eating watercress regularly has health-care effects such as clearing away heat and dampness, moistening lung and relieving cough, dredging menstruation and diuresis, and eliminating fatigue. It is one of the main leafy vegetables planted in autumn and harvested in winter and spring in Guangdong Province. Watercress is planted out of season in summer in Guangdong Province, and in Shuikou Town, Yangshan County.

First of all, two kinds of watercress:

(1) Guangzhou species. After years of cultivation, the varieties originally introduced from Macao have performed well, taste delicious and taste good, and are the leading varieties in South China. The plants are creeping upward, with stems 30-40 cm high and 6-8 cm thick, with lateral stems branching from the axils of basal leaves. The leaves are odd-numbered pinnate compound leaves, and the lobules 1 ~ 4 pairs are nearly round, watercress-shaped, dark green, and turn reddish brown when exposed to low temperature, with a slight pungent smell. Every node can produce new roots, the stems are soft and brittle when they are young, and the fibers increase when they are old. This variety has strong adaptability and can be planted in ordinary vegetable fields except paddy fields, but its quality is not as good as paddy fields. The growth period is short, from planting to initial harvest for 20-30 days, and then harvest once every 20 days or so. In winter, the planting and harvesting period is from June 165438+ 10 to April of the following year, and the yield per mu is 4000-5000 kg. Under general cultivation conditions, it is impossible to blossom and bear fruit, and the propagation method of cutting seedlings is often used.

(2) Baise species. Also known as Baise watercress, it is a cultivated variety in Baise, Guangxi, and is widely cultivated in Guangxi and Zhanjiang, Guangdong. Originally introduced from Europe, it has become an excellent variety suitable for local cultivation conditions after long-term planting, and can be planted in paddy fields and ordinary vegetable fields. Its characteristics are similar to those of Guangzhou species, but the difference is that it can blossom and bear fruit every year, and it can be propagated by seed seedling or cutting seedling. This variety has wide adaptability, crisp stems and leaves, less fiber and good taste, but its yield is low, about 3000 kg per mu.

Second, the requirements of douban on environmental conditions:

(1) temperature. Western food likes cold and cool, is afraid of heat, has strong cold resistance and can endure frost for a short time. The optimum temperature for growth and development is 15 ~ 25℃, with 20℃ being the best. When the temperature is lower than 15℃, the growth is slow. When the temperature exceeds 25℃, although the plant grows fast, the plant is thin, the leaves are yellow, and many adventitious roots grow on the nodes, resulting in poor quality.

(2) lighting. Douban needs strong light, and it is best to have 7-8 hours of light every day. Even in rainy days, when the plants are shaded and the light is insufficient, the main stems are long, the leaves are thin and yellow, and the quality is degraded.

(3) moisture. Watercress likes wet conditions, which can be planted in ditches or hydroponics (nutrient solution soilless culture). But in summer, the temperature is high and the ventilation is not good, which is easy to produce rotten seedlings.

(4) soil. Watercress has wide adaptability to soil, loam, sandy loam and clay can be cultivated, but fertile neutral or slightly alkaline clay loam or loam is the best. Suitable for paddy field planting and dry land planting, but always keep the soil moist.

(5) nutrition. It needs a lot of fertilizer, and nitrogen, phosphorus, potassium and trace elements should be applied together. The absorption rate of nitrogen, phosphorus and potassium is 1:0.4:0.9. Too much nitrogen fertilizer can easily lead to excessive growth, poor quality and easy infection.

Three. Key points of cultivation management

(1) land selection

Cabbage likes cold and cool, is not heat-resistant and suitable for water. In summer, it can be planted out of season or at low altitude, but it must be planted in a place where there is cold running water underground, and the water temperature (field water temperature) should not exceed 25℃ at the highest, or in a shady place at a higher altitude (more than 500 meters), and there should be a cool water source nearby. The traffic conditions at high altitude should be convenient and convenient for transportation. The most suitable soil for planting is sandy loam with good permeability.

(2) Soil preparation, fertilization and border tillage.

In order to cultivate watercress in dry land, we should choose plots with convenient irrigation and drainage, combine with ploughed land and apply sufficient pre-fertilizer, and apply 3000 ~ 4000 kilograms of decomposed fine organic fertilizer per mu to make a flat border with a width of 1.0 ~ 1.5 meters, and level the border surface.

(3) sowing and raising seedlings:

Sowing can be carried out from August to February of the following year, but the suitable period is 9-65438+1October. Early sowing has a hot climate, so it is advisable to raise seedlings by shading. Choose a flat garden in the shade, covered with fertile fine soil, with a thickness of about 6- 10 cm. It is best to dry the broken fertile pond mud, with a diameter larger than that of ordinary sand. Generally, base fertilizer is not applied. Spread out, soak in water, gently flatten with wooden boards until the surface is slightly pulpy, and sow; Or turn it into mud after ploughing and harrowing in the paddy field, and the mud will precipitate and sow the next day. Because the seeds are small, it is best to fully mix the dry fine sand or add a little lime before sowing. Then divide the seeds into several small sections according to the seedbed, and divide the seeds into corresponding parts, so that the seeds can be evenly sown without covering soil or watering, and then build a shade shed with a height of 1-2 m and a width of 1-5 m, slightly inclined to the south. The shading material should be a black shading net with a light transmittance of 70%. If you use branches, use pine leaves instead of broad-leaved branches to avoid falling leaves covering the seeds. There should be scattered light in the shed to prevent leaves from covering the seedlings. The film on the roof of the shed prevents the rain from splashing. About half a month after sowing, uncover the film, gradually remove the shade, and cultivate strong seedlings. 20-25g seeds per mu, about15m2 seedbed.

(4) Transplanting and field management

(1) Cultivate strong seedlings. Breeding with seeds needs to cultivate strong seedlings, and cutting with tender stems only needs stem cutting and transplanting.

(1) seed propagation. Before sowing and seedling raising 1 month cultivation, seedling raising in protected areas in early spring and winter, and seedling raising in the open field in other seasons. Choose fertile land, apply base fertilizer properly, make a seedbed with a width of 1.5m, water the bottom after the bed surface is leveled, and then sow. Generally, 3-4g seeds are sown per square meter, and 1 mu is planted in a seedbed with a width of1.5m2.. Because the seeds are small, in order to sow evenly, 50 grams of seeds should be mixed with the fine sand in half a washbasin and sown together. After sowing, the fine sand should be covered about half a finger thick, and the border soil should be kept moist to facilitate germination and emergence. If the fertility is insufficient after emergence, a small amount of quick-acting chemical fertilizer can be applied appropriately to promote strong seedlings, and can be transplanted when it grows to 12 ~ 15 cm.

② Cutting propagation. Taking advantage of the strong ability of stem nodes of watercress to regenerate adventitious roots, it is easy to survive by cutting its tender stems, which is very convenient for the propagation of non-flowering and fruiting varieties. The mother stem can overwinter in the greenhouse in winter. Before planting, you only need to cut and transplant thick and tender stems with about 5 ~ 6 nodes and a length of 12 ~ 15 cm. When there are not enough seedlings, you can even plant them in 2-3 knots. Generally, 4-5 mu of land can be planted for each mu of reserved seedlings. For example, in warm seasons, stems can be directly cut from the production site and then transplanted to expand the production area.

(2) Colonization. According to different cultivation methods, after the planting time is determined, select strong seedlings with the height of 12 ~ 15 cm or cut off tender and strong stems, plant them in the soil for 3 ~ 5 cm, and plant 1 ~ 3 plants in each hole, preferably semi-horizontally, with the row spacing of10 cm×/kloc.

For off-season cultivation in summer, transplanting seedlings and cutting, transplanting old seedlings and stout seedlings are generally started in early May. Apply human organic fertilizer in the field, and spread the decomposed farmyard manure evenly in the field, combined with soil preparation. To trim the rake, the water depth should be slightly higher than the mud surface. Leave homework rows every 3.3 meters, and open deep ditches around the field to facilitate irrigation. Planting row spacing 10- 13cm, plant spacing is about 7cm. When planting, put the tender stems on the field surface, and let several bases stick in the soil, then the roots can grow. There must be cold running water in the field at ordinary times, and the flow rate of water depends on the water temperature. If the temperature is high, the flow speed should be fast. If the water temperature in the field is not high, you can slow down. In order to make watercress grow well, the water temperature should be controlled in the range of 18-22℃. If the temperature is too high and the growth is not good, the leaves of watercress will turn yellow Choose to apply quick-acting fertilizer on cloudy days or in the afternoon, block the surrounding water inlets without releasing water, or leave a small amount of running water, and apply about 5 kilograms of compound fertilizer per mu. Don't run water before douban absorbs fertilizer. In summer, watercress is most afraid of white rain. If possible, it can be covered with sunshade net, and the coverage height is about 1 m. It has a great effect on preventing the influence of rainstorm, and can also improve the quality and yield of watercress.

(3) On-site management. Dry land cultivation should always keep the soil moist after self-planting, and avoid water exposure in the sun at noon and in the morning and evening when it is hot. In case of heavy rain, drain water in time to prevent plants from being flooded, so as to avoid rotten stems; Protected cultivation is mainly to control the temperature suitable for growth and increase the light as much as possible to prevent injury. No matter in dry land cultivation or paddy field cultivation, available nitrogen fertilizer should be used as the main topdressing immediately after transplanting, and topdressing should be 65,438+0 times each time after cutting, with 5.0 ~ 7.5 kilograms of ternary fertilizer per mu as the standard, and water should be applied immediately after topdressing in dry land. Top dressing in cold season can also use decomposed fine organic fertilizer, each time per mu 1000 ~ 1500 kg. If there are many weeds in the growing period, they should be pulled out in time.

(5) Pest control

1, control of common diseases of watercress.

The main diseases of watercress are gray mold, Sclerotinia sclerotiorum and brown spot.

The pathogen of botrytis cinerea is botrytis cinerea, which mainly occurs in the adult stage, mostly infects from the aged petiole at the base or from the injured petiole, causing light brown necrosis and rot at the diseased part, and producing botrytis cinerea on its surface, that is, conidiophore and conidia of the pathogen. With the development of the disease, the disease spread rapidly up and down and around, causing many peripheral leaves to be infected and necrotic, and finally dried up and rotted.

Sclerotinia sclerotiorum is the pathogen of Sclerotinia sclerotiorum, which can occur in all growth stages, especially in adult stage. Most pathogens began to infect the stem base or lower petiole, which made the diseased part rot like water stains, and developed rapidly in all directions, causing many outer leaves to rot and die. With the development of the disease, dense flocculent white mold is produced on the surface of the affected area, which gradually turns into black rat dung sclerotia.

Brown spot mainly harms leaves. The lesion is round or oval, brown, with obvious or inconspicuous wheel marks. In severe cases, the leaves will dry up. In hot and humid weather or too much nitrogen fertilizer, there are many diseases.

The prevention and treatment methods of these three diseases are as follows:

(1) Clean the countryside; After the previous harvest, the remaining plants, rotten leaves, weeds, etc. will be cleaned up and transported out of the ground for harmless treatment such as high-temperature composting and deep burial to prevent the bacteria from spreading underground.

(2) Cultivate disease-free seedlings, pay attention to ventilation, dehumidification and properly adjust the temperature during the growth process, and remove diseased plants and leaves in time, take them outside the shed and burn them to prevent germs from falling into the soil.

(3) 40% chlorpyrifos with 800 ~ 1000 times or 45% Tektronix suspension with 800 times was used in the early stage of the disease. If conditions permit, room temperature spraying or dust spraying is better. More than 40% is used to prevent brown spot disease? Spraying 500 times of sulfur suspending agent, 500 times of 50% thiophanate-methyl wettable powder or 600 times of 60% mildew-proof superfine powder.

2. Control of watercress pests.

The main pests are Plutella xylostella and aphids.

Plutella xylostella is also called Plutella xylostella, Lepidoptera, Plutella xylostella and so on. , the most important pest of cruciferous vegetables, is widely distributed all over the country, especially in southern China and areas where leafy vegetables are planted all the year round. It can harm broccoli, kale, watercress and other crops, mainly damaging leaves and forming "skylight" transparent spots. Large larvae can eat the leaves into holes or nicks, and in severe cases, they will eat the leaves into a sieve. The adult diamondback moth is a small gray-brown moth with long and narrow wings. There are Huang San zigzag ripples on the front and rear wings, which are roof-shaped when the wings are closed. The mature larva is about 65438±0cm long, with tapering ends, spindle shape, yellow-brown head, obvious body joints, and buttocks and feet extending backward beyond the ventral end. The pupa is spindle-shaped, covered with a thin gray transparent cocoon, through which the pupa body can be seen.

In the hot summer season, affected by high temperature, rainy weather, natural enemies and other factors, the number of Plutella xylostella decreased significantly. If cruciferous vegetables are continuously planted or interplanted every year, the diamondback moth will be rampant and suffer serious losses.

(1) Control methods of Plutella xylostella;

Because of its small size, fast reproduction and strong resistance to various pesticides, comprehensive control measures must be taken according to the biological characteristics of Plutella xylostella to achieve ideal results.

Since Plutella xylostella only harms cruciferous vegetables, it is necessary to avoid continuous cropping and interplanting of cruciferous vegetables and cut off the insect source within a certain range. At the same time, pay attention to strengthen the prevention and control of pests and diseases at seedling stage to avoid vegetable seedlings carrying pests. After harvesting, clean and concentrate the residual plants and leaves to eliminate the residual insect source.

Using the phototaxis of adults, a black light or a high-voltage insect trap lamp is set to trap and kill adults. Using the mating and reproductive habits of Plutella xylostella, we can choose special sex attractant cores and matching traps to trap and kill adults.

Scientific pesticide control, because Plutella xylostella has many generations and uses pesticides frequently, it is easy to produce drug resistance. Therefore, we should pay attention to the alternate use of pesticides with different characteristics and give priority to the use of non-chemical pesticides in pesticide control.

First, choose microbial pesticides, such as BT powder of Bacillus thuringiensis, compound BT emulsion and 500 ~ 1500 times powder, and pay attention to spraying when the temperature is above 20℃.

Secondly, choose special pesticides for insects, such as 2.5% Caixi SC1500 times, 25% Deberon No.3 SC1000 times, or 20% Deberon SC/3000-5000 times. Note that the application time is about 3 days earlier than that of ordinary pesticides.

Thirdly, choose antibiotic insecticides, such as 40% Qingyuanbao EC 1000 ~ 1500 times liquid spray.

Fourthly, plant pesticides are selected, such as 0% azadirachtin aqueous solution 800 ~ 1000 times or 0.5% resveratrol solution 800 ~ 1000 times.

Fifth, use chemical pesticides with low toxicity, low residue and high activity, such as 3% Meuron EC1000 ~ 2,000 times or 10% herbicide suspension 1200 ~ 1500 times.

(2) Harmful symptoms and prevention of aphids:

There are two forms of aphids, wingless aphids when conditions are suitable and winged aphids when conditions are not suitable. It is harmful to the young leaves and heart leaves of vegetable plants, causing the heart leaves and young leaves to atrophy and deform, and the vegetable plants grow poorly and cannot bear balls normally. In severe cases, it will induce coal pollution and affect product quality. Vegetable aphids are mostly light green, light yellow and greenish yellow. More than 10 generations can occur in North China, and 30 ~ 40 generations can occur in South China. Generally, it will not cause harm in winter in northern areas, but it can occur sporadically on greenhouse vegetables. Vegetables in the open field often have two peaks in spring and autumn. In the south of China, Myzus persicae can do harm all year round. Myzus persicae likes yellow and orange, but is afraid of silver gray. It can be used to prevent and control color preference.

According to the fear of winged aphids to silver gray, silver gray films can be laid or hung at intervals in vegetable fields to drive away aphids.

According to the preference of winged aphids for yellow, winged aphids can be trapped by hanging the yellow board of armyworm in the field, or by placing a yellow basin about 20 cm from the ground, in which 0. 1% soapy water or washing powder water is filled to trap and kill winged aphids.

Chemical control should be carried out in time, because aphids have a short generation cycle, rapid reproduction and rapid spread, and most of them gather in dry and hidden places on the leaves of Chinese cabbage or the back of leaves, and the spraying requirements are meticulous and thoughtful. It is best to use aerosol or normal temperature smoke spray technology to control aphids in protected areas. Spray control can be carried out by using 3000 ~ 4000 times of 20% Kangfuduo concentrated soluble solution, 800 ~ 1000 times of1000 times of/kloc-0 ~ 2000 times of 3% Mopulan EC 1000 ~ 2000 times, and 20% aphid killing aerosol is used in the nature reserve, with 0.4 capsules per mu.

(6), harvesting

The growth process of new stems and leaves of watercress is the process of product formation. It takes about 20 ~ 30 days from planting to first harvest. The tender stem is about 25 cm long and can be harvested 1 time. Cut off the tender stems with scissors or sharp knives, bundle them into small bundles, and cut off their heads for listing. The yield per mu is about 1 1,000 kg per crop, and it can be cut again every 10 ~ 20 days. In early spring or winter, due to the low temperature, the growth is slow, and the harvest can be about 1 month/time. For example, when the plant blooms in June, the upper part of the plot without seeds can be cut off, leaving the middle and lower stolons to promote the germination of new stems and continue production and harvest.

Harvest watercress should be carried out in the evening or cloudy morning to avoid sunlight. The recovery standard should be determined according to the requirements of domestic sales or export. Stack bamboo baskets layer by layer, leaving ice cubes in the middle and ice cubes on top. Try to sell early in the evening. If possible, it can be transported by refrigerated truck. Except crushed ice, the temperature of the refrigerator should be adjusted to 0-5℃ ... Fertilization should be applied after each harvest to promote its re-growth. Generally, a large number of harvests begin in mid-June and end on 10 in late June. The yield per mu is 2500-3500 kg, and the high yield can reach 5000 kg if the harvest time is long.