Main Cultivation Techniques Of Greenhouse Strawberries

By Author: doris zhang
Total Articles: 67
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Strawberry is a perennial evergreen herbaceous plant belonging to the Rosaceae family. In horticulture, it is classified as a berry. Strawberry berries are bright red, fragrant and juicy, sweet and sour, and rich in nutrients. In the global berry fruit production, its cultivation area and output are second only to grapes. It is a global fruit and is deeply loved by consumers at home and abroad.

Strawberries were introduced to our county and have a history of more than ten years. Since planting strawberries has high economic income, and the county's land resources are limited, the development of the strawberry industry is a new way for our county to adjust the structure of the planting industry and develop efficient agriculture. The advantages of greenhouse strawberry cultivation are obvious: First, the strawberry planting time is early, the fruit is early, the production cycle is short, and the results are quick. Planting begins in September, bears fruit in November, and ends in May of the following year. Not only does it enrich the varieties of winter and spring fruit markets, but also during traditional festivals such ...
... as New Year's Day and Spring Festival, the market demand is strong and the product prices are high. Second, strawberry cultivation is easy, management is convenient, production cost is low, yield is high, and profit is good, which is suitable for the county's requirements for adjusting the farmland structure and developing efficient agriculture.

In order to solidly promote our county’s “Quality Training Project for Ten Thousand Rural Fisheries Labor Forces”, effectively improve the overall quality of the labor force in rural fishing areas, and accelerate the transfer of employment from rural fishing areas. Today we are holding this greenhouse strawberry cultivation technology training class here. Based on the biological characteristics of strawberry,hydroponic dutch buckets combined with the actual geographical and climate characteristics of our county, we will introduce it in six aspects.

1. Selection of varieties

In terms of variety layout, Fengxiang is used as the main planting variety, and Qianqian and Libao No. 1 are vigorously demonstrated and promoted, and Zhangji is planted in combination.

1. Fengxiang. Introduced from Japan, this variety has strong growth potential, an open plant shape, round and large leaves, thick and dark green. The plant has fewer leaves and the leaf growth rate is slower. This variety is highly resistant to powdery mildew and gray mold.

2. Millennium. Introduced from Japan and bred by the Provincial Academy of Agricultural Sciences. This variety grows vigorously, with semi-erect plants and thick, dark green leaves. Light dormancy, early maturity. The fruit is large, round and hammer-shaped, with a dark red surface, glossy, moderately sweet and sour, strong flavor, and resistant to storage and transportation. The ability to resist powdery mildew and anthracnose is stronger than that of Fengxiang, but the ability to resist red spider mites is weak.

3. Berry No. 1. Introduced from Japan, this variety has vigorous growth, semi-erect plants, thick green leaves, and shallow dormancy. The fruit is round and hammer-shaped, with a red surface. The fruit is resistant to storage and transportation and has strong disease resistance.

4. Zhang Ji. Introduced from Japan, this variety grows vigorously and has a relatively upright plant shape. The leaves are oblong. The degree of dormancy is shallow. The fruit surface is crimson and shiny. The pulp is soft and juicy, fine in texture, more sweet than sour in flavor, and of excellent quality. The fruit has poor storage and transportation resistance. It has good resistance to powdery mildew and gray mold, but not to anthracnose.

2. Seedling cultivation

The goal of seedling cultivation is to cultivate disease-free and robust strawberry seedlings with a rhizome thickness of more than 10 mm and a weight of more than 20 grams when planted.

1. Preparation of seedling fields

Choose loose soil with easy irrigation and drainage for seedling cultivation. It is best to use raw land or plots that have not been planted with strawberries for more than a year.

The seedling land should be plowed deeply 7-10 days before planting to make a 2-meter-wide border. A planting ditch should be dug in the middle or on the edge, and decomposed fertilizer and compound fertilizer should be applied in the planting ditch. Planting one acre of strawberries requires about 250 mother seedlings, 500 kilograms of field fertilizer and 10 kilograms of compound fertilizer.

2. Selection of mother seedlings

It is best to use special strawberry mother seedlings, which should be planted in the open field in October of the previous year.

If you use plants from the production garden, you should choose disease-free and healthy plants as mother seedlings.

3. Mother seedling planting and management

Planting should be done from the end of March to early April. After planting, water should be fully irrigated to promote survival. Cold temperatures and dryness can inhibit grape stem growth. The use of small sheds for heat preservation in the early stage can promote early and frequent growth of grape stems. After the mother plant survives, spray 50-1000PPM gibberellin, 5ML per plant, and spray again after a week to facilitate the growth of grape stems.

In early June, based on the growth of the seedlings, spread a small amount of compound fertilizer throughout the garden on rainy days, about 5 kilograms per acre. Combined with pest control, 0.2% urea and 0.2% potassium dihydrogen phosphate can be used as top dressing outside the roots.

Seedling cultivation takes place during the hot and humid season, when pests and diseases are common, so prevention and control must be strengthened. In addition, yellow leaves, diseased leaves and diseased plants should be cleaned up in time to cultivate strong strawberry seedlings.

3. Management of strawberry fields

Strawberry garden selection and land preparation

The strawberry garden should have sufficient sunlight, slightly higher terrain, flat ground, easy irrigation and drainage, fertile and loose soil, and the previous crops should be beans or onions and garlic vegetables. Weeds and underground pests should be eliminated in the garden first. 50% phoxim emulsifiable concentrate 1000 times can be sprayed (5-6 cm of moist soil) to control grubs, mole crickets and cutworms.

After one week, apply 5,000 kilograms of high-quality decomposed farm manure, 100 kilograms of superphosphate, and 50 kilograms of potassium chloride per mu. Combined with deep plowing of the garden and careful soil preparation, a border surface of 20 cm high and 50 cm wide is made, with a furrow width of 30 cm. The length of the greenhouse is limited to 20 meters, and there are 4 rows inside.

Requirements for environmental conditions for strawberry cultivation

1. Temperature requirements: The suitable temperature for photosynthesis of leaves is 20-25°C. During the vegetative growth period, stolons require high temperature and long sunshine for the development of stolons, with sunshine lasting more than 12 hours. The suitable temperature is night temperature 10°C and day temperature 23°C. During the flower bud formation period, flower bud differentiation requires short sunshine and low temperature, with sunshine less than 12.5 hours. Flower buds can differentiate when the temperature is 5-24℃; during the flowering and fruiting period, the optimum temperature during the flowering period is 25-28℃, and the night temperature must be above 5℃; during the fruit development and hypertrophy stage, the day temperature is 17℃, the night temperature is 9℃, and the fruit is mature. It takes about 60 days to fully enlarge. High temperature will promote ripening. If the temperature is too high, the fruit will become smaller.

2. Moisture requirements: During the rainy season from June to July, the nursery land should not accumulate water; during autumn planting, water should be sufficient, and the soil should always be kept moist to improve the survival rate of planted seedlings; the flowering period requires air humidity of 40-60% and soil humidity of 40-60%. 80%; during the fruit development and hypertrophy stage, water should be irrigated in time, when the water demand is the largest; when the fruit is close to maturity, water should be controlled appropriately.

3. Soil requirements: Suitable soil is loose, fertile, well-permeable loam or sandy loam,bato bucket and the suitable soil pH value is between 5.7-6.5; strawberries are very sensitive to soil salt concentration and harmful gases, so base fertilizer should be applied to the soil. When applying fertilizer and top dressing, the appropriate dosage should be mastered.

4. Light requirements: The light requirements of strawberries are mainly reflected in two aspects, light intensity and day length. The required light intensity is 20,000-50,000 li; the suitable day length during the flowering, fruiting and seedling stages is 12-15 hours, and the flower bud differentiation stage requires low temperature and short days.

(1) Transplanting:

In order to strive for strawberry to be on the market from the end of January to the beginning of February, the time for transplanting strawberry seedlings in the breeding nursery to the greenhouse border should be in early September. The seedlings should be planted and transplanted as needed, with 2 rows planted per row, row spacing 27 cm, hole spacing 20 cm, and 12,000 plants per mu. When planting, the inflorescences of plants in the same row face the same direction, so that the strawberry seedlings are arched towards the intended growth direction of the inflorescence, the center of the seedlings is exposed on the edge of the border, and the roots are flat and buried in the loose soil. Water the planting water in time and bury the exposed roots into the soil. .

(2) Colonization and management

1. Soil disinfection.

The continuous cropping of strawberries or the previous cropping of tomatoes, eggplants, melons, etc. must be preceded by soil disinfection or rice rotation. There are two simple and easy ways to use the solar potential energy in the high temperature season of July and August to disinfect the soil: First, remove weeds in the field, spray pesticides and fungicides, and then use non-abrasive pesticides on the soil surface after plowing. The hole is tightly covered with old agricultural film, and the temperature under the film can be increased up to 65 degrees Celsius to achieve disinfection. The second is to spread pesticides and fungicides after plowing the garden, and soak it in water for a week to disinfect the soil.

2. Plow the land and apply sufficient base fertilizer

After the soil is disinfected, plow, harrow, and apply base fertilizer. Then dig ditches, make borders, and prepare the land. This work should be completed 15 days before planting. Pay attention to the following points when applying base fertilizer:

(1) The amount of base fertilizer should be sufficient, mainly organic fertilizer. Apply 3000-4000KG of fence fertilizer, 100KG of cake fertilizer, and 80KG of compound fertilizer per mu. The amount of base fertilizer accounts for more than half of the total fertilizer amount.

(2) The fertilizer must be fully decomposed. It is best to use EM original fermentation compost. Fresh fertilizer can easily cause fertilizer damage such as "seedling burning" and bud blight.

(3) The base fertilizer should be fully mixed with the soil. The strawberry root system is shallow, and most of it is distributed in the 26 cm soil layer. Therefore, the base fertilizer cannot be applied deeply and should be applied in the 15-20 cm soil layer.

Land preparation requires the use of deep trenches and narrow borders. Each trench is about one meter wide, the trench width is 40 cm, the trench depth is 30 cm, and the border surface is maintained at 55 cm. The border surface is made into a turtle-back shape to prevent water accumulation in the border.

3. Colonization

The planting period of greenhouse strawberries is determined based on the degree of differentiation of terminal flower buds. Generally, the optimum period for colonization is when 50% of the plant top flower buds differentiate. In our county, the planting period is generally around mid-September.

Single frogs are planted in double rows in a triangle, with a row spacing of 25-28 cm and a plant-to-plant spacing of 18-20 cm. About 7,000 strawberry plants are planted per acre. When planting, attention should be paid to directional planting, so that the arched back of the strawberry seedling roots faces the ditch. Try to transplant with soil as much as possible. The planting should not be too deep or too shallow. It is better not to bury the heart at the top and not expose the roots at the bottom.

4. Field management before shed shed

After planting, water should be watered immediately. The first watering amount should be large and it should be watered thoroughly. Afterwards, watering should be done 1-2 times a day. After the seedlings survive, there is no need to water as long as the soil is not dry to encourage the roots to grow downward. After survival, the new leaves unfold and the grape stems and dead leaves are removed. Pay attention to preventing and controlling pests and diseases, including anthracnose, powdery mildew, spider mites, aphids, etc.

5. Temperature and humidity after the shed is closed

Generally from late October to early November, when the average temperature drops to 16 degrees Celsius, it is the best period for heat preservation. After the shed is buckled, the mulch film should be laid immediately. It is advisable to fully cover the mulch film.

After heat preservation begins, it is easy to grow too vigorously. Temperature and moisture management must be carried out according to plant growth and temperature conditions. The temperature of the shed is maintained at 25 degrees Celsius during the day, with a minimum of no less than 20 degrees Celsius, and the night temperature is kept above 5 degrees Celsius. When the low temperature in the shed at night is below 5 degrees Celsius, double insulation is used at night to keep the temperature in the small shed at night above 5 degrees Celsius.

The suitable humidity in the greenhouse is 40-60%. Therefore, when laying the mulch film, the ditch walkway should be fully covered without leaving bare ground to prevent the evaporation of ground water. Combined with temperature management, ventilation should be paid attention to when the temperature is high. Even in the cold winter, ventilation and cooling should be used when the temperature is high at noon to reduce diseases and promote strawberry pollination and fertilization.

6. Fertilizer and water management after planting

In terms of fertilizing greenhouse strawberries, in addition to applying sufficient base fertilizer, top dressing should also be carried out in an appropriate amount at a timely manner. The time and frequency of top dressing are roughly as follows: for the first top dressing, about 20 days after planting, apply 20 kilograms of nitrogen, phosphorus and potassium three-element compound fertilizer per acre; the second top dressing is about 20-25 days apart from the first top dressing, every acre. Apply 10-15 kilograms of nitrogen, phosphorus and potassium ternary compound fertilizer per mu; this second application of fertilizer can be spread directly between the rows of the border, and the soil should be loosened and watered after application; for the third top dressing, when the top fruit reaches the size of a thumb ( About early November), be careful not to apply top dressing when the top flowers are blooming; the fourth top dressing, when the top fruits begin to be harvested, is about late November; the fifth top dressing, when the top inflorescences are harvested, is about Mid-December. In the future, when each inflorescence fruit starts to be harvested, it should be carried out as appropriate, and it is usually applied every 20 days or so. After the third time, top dressing is usually done after mulch covering, fertilization and irrigation. The concentration of liquid fertilizer is controlled within 0.35%. It should not be too concentrated to prevent fertilizer damage. Apply 3,000 kilograms of liquid fertilizer per acre, and use nitrogen, phosphorus, and potassium in combination. In production, foliar fertilizers are also used for top dressing outside the roots, and Greenway 18 is the most effective foliar fertilizer for strawberries.

4. Plant production management

1. Cultivating and fertilizing. Cultivating and loosening the soil facilitates the decomposition of organic matter. From November to December, shallow cultivating should be carried out three times. Topdress once each during the initial flowering period and early fruit setting period. Apply 10 kg of urea, 20 kg of phosphate fertilizer, 10 kg of potassium chloride, or 35 kg of ternary compound fertilizer per mu.

2. Management of flower buds in the early stages of differentiation. Strawberry seedlings transplanted in early September should be covered with a sunshade net for shade in addition to timely replenishing of water. The net is 1.2 meters above the ground, making it easy for personnel to operate. Dead leaves, old leaves, axillary buds and stolons should be removed in time to keep 5-6 leaves.

The differentiation of strawberry flower buds requires lower temperatures and short days, so a straw thatch (straw curtain) can be added to the sunshade net. Through the process of uncovering and covering the grass thatch, short-day conditions and lower temperatures are artificially created to promote the differentiation of terminal inflorescences and axillary inflorescences.

3. Irrigation and drainage methods. During the early stages of flowering and berry growth, water once each. It is advisable to use furrow irrigation, so that the water reaches 2/3 of the height of the furrow, so that the water gradually penetrates into the soil and the remaining water in the furrow is discharged. If there is a drought, watering should be done once every 5-7 days. Use a section of metal pipe on the front end of a rubber pipe for hole irrigation, which not only saves water, but also keeps the border soil loose. When it rains in autumn, water should be drained in time. Drainage channels should be built around the strawberry garden early so that the water in the shed can be drained away.

4. Cover with plastic film. From October to early November, it is the end of the differentiation period of strawberry inflorescences, and the sunshade net can be removed. Cover the greenhouse with plastic film after the "beginning of winter" and cover it with film before the "heavy snow" to keep the temperature in the greenhouse at 28-30°C. In "warm winter" years, the middle shed is covered with plastic film during the "winter solstice" season. In "cold winter" years, the large and middle sheds should be covered with plastic films at the same time. In short, during the "little cold" to "big cold" seasons, the temperature in the shed should be kept above 25°C, at least above 23°C. Only when the above temperature is met, strawberries can grow normally.

5. Ventilation operation. The soil humidity for strawberry seedlings to grow should be 70%-80%. The air humidity in the shed is preferably 60%--70%. Therefore, when the temperature in the shed exceeds 30°C, ventilation should be provided. From November to December, the plastic films at both ends of the greenhouse and middle shed should be uncovered for ventilation from 10 a.m. to 3 p.m.

When the humidity in the shed exceeds 70%, ventilation should also be provided to reduce the air humidity in the shed.

When bees are kept in the shed during the flowering period, nylon wire mesh can be made at both ends of the large and middle sheds to facilitate smooth ventilation.

Another function of greenhouse ventilation is to prevent strawberry powdery mildew.

6. Management of leaf picking, fruit thinning

Senescent leaves produce less photosynthetic products and consume more respiration, which is detrimental to strawberry growth and berry development. The unnecessary occurrence of stolons also consumes maternal nutrients. Therefore, during the fruiting period, the lower senescent leaves should be removed in time, and the stolons should be removed as soon as possible. In addition, thinning out certain high-level flowers and fruits before and after flowering can not only reduce the rate of deformed fruits, but also facilitate the concentrated supply of nutrients for the development of low-level flowers and fruits, increase the size of the fruit, and improve the uniformity.

7. Gibberellin treatment

Spraying gibberellins in greenhouse strawberry cultivation can prevent plants from entering body sleep, promote the elongation of pedicels and petioles, increase leaf area, and promote flower bud differentiation.

The time and frequency of gibberellin treatment are related to the variety. Generally, for varieties with shallow dormancy and vigorous growth, such as Fengxiang, Qianqian, Zhangji, Beibao, etc., spray once with a concentration of 5-10PPM. The dosage for each plant is 5ML, focusing on the center of the seedlings. Gibberellins are used when 50-70% of the plants have buds. Note: Do not use too much gibberellin, otherwise it will appear leggy and the fruit cluster rate will decrease.

8. Keep bees free

Keeping bees on strawberries in greenhouses can promote strawberry pollination and fertilization, reduce deformed fruits, increase fruit setting rate, and significantly increase yields.

Three boxes of bees can be placed in one acre of greenhouse, and the stocking time should be carried out 5-6 days before the strawberries bloom, so that the bees can fully adapt to the environment in the greenhouse before flowering until March of the following year. If serious pests and diseases occur in the shed and require spraying or fumigation, the beehives must be moved outside the shed. Bees need to be artificially fed when there are few flowers in the greenhouse.

9. CO2 gas fertilizer

CO2 gas fertilizer is an important raw material for the synthesis of carbohydrates through photosynthesis. The concentration of CO2 in the greenhouse is often lower than that in the atmosphere. Adding CO2 can promote growth, advance the maturity period by 1-2 weeks, increase yield, and improve fruit quality.

At present, most of the production uses reaction method to provide CO2, using ammonium bicarbonate and sulfuric acid, and passing the CO2 generator to generate CO2 directly into the greenhouse.

5. Comprehensive prevention and control of pests and diseases

The prevention and control of strawberry pests and diseases in greenhouses should be based on "agricultural control as the mainstay and pesticide control as a supplement." That is to say, we can prevent the occurrence of diseased and rotten fruits by adopting measures such as virus-free strong seedlings, high ridge planting, mulching with plastic film, crop rotation between floods and droughts, and avoiding drought and high humidity. When diseased leaves and fruits are found in the field, they must be removed promptly to prevent their spread.

Common diseases and insect pests on strawberries include: gray mold, powdery mildew, anthracnose, root rot, bacterial wilt, spider mites, aphids, Spodoptera litura, etc. Strawberry diseases and insect pests seriously affect strawberry yield and quality, and affect food safety. Therefore, strawberry pests and diseases should adopt a comprehensive prevention and control policy: first, select disease-resistant varieties and establish a dedicated mother plant garden; second, strictly disinfect seedlings and soil; third, strengthen field management and promote healthy cultivation; fourth, spray pesticides Prevention and treatment. Especially for strawberry diseases, prevention should be the focus, focusing on targeted chemical control in the early and onset stages.

Pay attention to heat preservation, ventilation, and dehumidification, issue pest and disease forecasts in a timely manner, fully implement the plant protection policy of “prevention first, comprehensive prevention and control”, carry out timely classified guidance, effectively control hazards, and ensure safe strawberry production.

Based on strengthening cultivation management, fully apply agricultural, physical and other prevention and control measures to effectively control the occurrence and harm of pests and diseases. Promote the use of hose drip irrigation and full mulching film coverage (furrow covering) or rice straw padding in the ditch to control the air humidity in the greenhouse and prevent flooding in strawberry production areas. Timely clean up diseased leaves, fruits and other diseased remains in strawberry production fields, and destroy them in a centralized manner to reduce the source of infectious diseases. It is recommended to use three-element compound fertilizer for top dressing in strawberry orchards, and avoid excessive application of nitrogen fertilizer. Manage shed membrane opening and closing management should be done well to improve ventilation and light transmission conditions. Especially when it is cloudy after fertilizing water, the shed should be opened in time to avoid harmful gases such as ammonia and nitrogen.

1. Verticillium wilt. When the disease occurs, 1-2 leaves turn yellow, bend and become deformed, and gradually die. Prevention and control methods: In spring, you can apply more chopped straw and sawdust in the garden, add farm manure, plow it, plow it into the soil, make a border, fully irrigate it, cover it with mulch, and let it ferment completely through solar energy. It not only increases the organic matter, but also completely disinfects it. This method can also prevent and cure root rot and wilt disease.

When verticillium wilt plants are found, remove them promptly and replant them. After replanting, use 10% Duokangling aqueous solution 80 times, or 8% Bacteriocin (Ningnanmycin) aqueous solution 1000 times for irrigation and control.

2. Botrytis gray mold is a flowering disease of strawberry and can occur on petals, fruits and leaves. If the fruit becomes infected, gray mold will grow densely, which will seriously reduce the yield. Prevention and control methods: Mainly for prevention, you can use "Yixunling" fumigant for fumigation control, 3 pieces per standard shed, fumigation at night, 3-4 times in a row, 7 days apart each time: 40 can also be used % Xicara (pyrimimethylamine) suspension 800 times liquid, 50% Nongliling (vinyl coreli) dry suspension 1000 times liquid, or 80% Dasheng M-45 (mancozeb) wettable powder 800 times liquid , or 50% promethaden (iprodione) wettable powder 800 times liquid, or 50% procymidone wettable powder 800 times liquid, or 75% chlorothalonil wettable powder 800 times liquid, etc. Spray control, every 7 —Once every 10 days, prevent and treat 2-3 times in a row. Pay attention to alternate medication.

3. Anthracnose: When diseased plants are found, remove them promptly and replant them. After replanting, use 25% Prochloraz EC 1000 times liquid, or 80% Dasheng M-45 wettable powder 700 times liquid, or Control by watering with 400 times of 20% Ronkebacterium (thiabendin) suspoemulsion, and control for 3-5 times in a row.

4. Powdery mildew: In the early stage of the disease, use 99.1% Luying (mineral oil) emulsifiable concentrate 300 times liquid, or 50% Tribeta (acetostrobin) dry; suspension agent 3000 times liquid, or 62.25% Xiansheng (nitrile) For prevention and control, use 600 times liquid of myclobutanil·manganese zinc) wettable powder, 1500 times liquid of 5% hypertonic myclobutanil, or 4000 times liquid of 40% Fuxing (flusilazole) emulsifiable concentrate. You can also use fumigation fumigants for prevention and control, 3 pieces per standard shed (6 meters x 30 meters) each time, fumigation at night, 3-4 times in a row, with an interval of 7 days between each time.

5. Aphids: During the period of spotting, choose 0.3% Aihe (Indonin) EC 1000 times liquid, or 70% Aimela (Imidacloprid) water dispersible granules 10000 times liquid, or 5% Adak (pyridinic acid). Insect beetle) wettable powder 1500 times liquid and other spray control.

6. Mites: Carry out key monitoring after the insulation work begins, and remove mites in time during the period when mites occur to reduce the source of mites. Before the strawberries bloom, when the number of spider mites per spider reaches 2-3, use 9.5% mite-killing (quinfenacet) EC 2000-3000 times, or 15% mite-sweeping (Pyridafen) EC 1500 times. spray control, or 1,200 times the solution of 5% thifenacet emulsifiable concentrate, or 2,000 times the solution of 57% acetate emulsifiable concentrate. Mix 99.1% Green Ying Cream 300 times into each of the above agents for better results.

6. Harvest at the right time

harvest. It takes about 30 days from strawberry seedlings to bloom and fruit set to when the berries color, soften and release their unique fragrance. After the strawberry berries are ripe, they should be harvested in batches and put on the market. The average strawberry yield per mu is 1,500 kilograms.

Greenhouse strawberry fruits are mainly eaten fresh and can only be harvested when more than 70% of the fruit surface is red. The temperature is low in winter and early spring, so the fruits should be harvested when they are 8-9 years old. As the temperature rises after early spring, the harvest period can be advanced appropriately. Picking should be carried out between 8-10 am or 4-6 pm. Do not pick or dry fruits to prevent them from rotting or deteriorating. When picking, you should handle, pick, and place it gently, and do not damage the calyx. At the same time, it should be stored and packaged in grades.