How to Grow Strawberries in a Greenhouse? A Complete Guide to Greenhouse Strawberry Cultivation Techniques
Strawberry belongs to the Rosaceae family and is a perennial herbaceous plant. In world small berry production, strawberries rank first. Strawberries are a cash crop with quick fruiting, early maturity, easy propagation, a short cycle and high returns. Below, the editor will briefly introduce how to grow strawberries in a greenhouse!
1. Choose suitable varieties or mix different varieties: Choose varieties such as Fengxiang and Mingbao that produce many flowers under low-temperature conditions, have a large amount of pollen, large and uniform fruit, good colouring, mild acidity and few deformed fruits. Varieties such as Qiuxiang, Baojiaozaosheng and Quanmingxing have less pollen and produce more deformed fruits, so varieties such as Chunxiang and Dana should be planted as pollinizers to facilitate pollination and fertilisation, reduce deformed fruits and increase the proportion of large fruits.
2. Choose disease-free strong seedlings: Disease-free strong seedlings have a well-developed root system and strong disease resistance, and the strawberries they produce are large, high-yielding and of excellent quality.
3. Apply sufficient high-quality base fertiliser: Increasing the application of high-quality decomposed farmyard manure can provide sufficient nutrients for strawberry growth, flower bud differentiation, flowering and fruit setting, and fruit development, enlarge the fruit size, and increase the sugar content and colouring of the fruit. Apply 2000 kg of decomposed chicken manure per mu as base fertiliser, combining furrow application with broadcast application.
4. Practise crop rotation and avoid continuous cropping: Crop rotation can improve the disease resistance of strawberries and reduce the number of deformed fruits and diseased or insect-damaged fruits. The open space between greenhouses can be fully used for cyclic rotation.
5. Increase light exposure: Insufficient light from 2 weeks before flowering to the flowering period will affect pollination and fertilisation and produce deformed fruits. Insufficient light during the fruit colouring period will lead to bland fruit and poor colour. On the premise of ensuring the temperature inside the greenhouse, the straw mats used for covering should be removed as early as possible and put back as late as possible. Hang reflective film on the north side inside the greenhouse to use reflected light to increase illumination. On cloudy or snowy days, incandescent lamps can be used for supplementary lighting.
6. Ridge cultivation and plastic film mulching: Ridge cultivation can reduce contact between the fruit and water dripping from the greenhouse film, enhance sunlight exposure to the fruit, reduce the occurrence of grey mould, and promote fruit colouring. Plastic film mulching can raise ground temperature, lower air humidity, prevent the fruit from directly contacting the soil, and help keep the fruit surface clean.
7. Strictly control temperature: The suitable greenhouse temperature is 22-25°C during the day and 8-10°C at night during the flowering period, and 20-24°C during the day and 6-10°C at night during the fruit enlargement period. Too high a temperature inside the greenhouse will shorten the fruit development period and make the fruit smaller.
8. Water and top-dress fertiliser in appropriate amounts: Water appropriately during the flowering and fruiting period, preferably by drip irrigation. Insufficient water during the flowering period will lead to poor pollination and fertilisation and produce deformed fruits. Insufficient water during the fruit enlargement period will affect fruit enlargement. During the flowering and fruiting period, spray 0.3% potassium dihydrogen phosphate solution 3-4 times in succession.
9. Supplementary pollination: Poor pollination and fertilisation is the fundamental cause of deformed fruits. Using bees for supplementary pollination can effectively reduce the occurrence of deformed fruits. Generally, 1 box of bees is placed in each greenhouse during the flowering period for pollination.
10. Timely prevention and control of pests and diseases: Spraying pesticides during the strawberry flowering period can easily induce deformed fruits. If pests or diseases occur during the flowering period, spraying should be done during a period with fewer flowers. Move the beehive out of the greenhouse before spraying, and move it back 1 week after application.
How to Grow Strawberries in a Greenhouse? Key Points of Greenhouse Strawberry Cultivation Techniques
In recent years, with the development of protected agriculture, the cultivated area of greenhouse strawberries has continued to expand. In the process of growing greenhouse strawberries, in order to increase strawberry yield and quality and improve economic returns, it is very important to do a good job in fertiliser and water management, preventing deformed fruits, and preventing early buds and early flowers. So, how do you grow strawberries in a greenhouse? Below is an introduction to the key points of greenhouse strawberry cultivation techniques. Let's take a look.
Image: Greenhouse strawberry cultivation
I. Covering the greenhouse and keeping warm at the right time
Generally, when the temperature drops below 5°C, a semicircular small arched frame should be promptly set up over the strawberry cultivation beds and covered with colourless plastic film. In the early stage after covering, attention should be paid to ventilation to prevent the temperature inside from exceeding 30°C, especially around noon on clear, cloudless days with strong sunlight, when high-temperature damage to seedlings should be prevented even more. In addition, when the minimum temperature inside the shelter is around 5°C, paper quilts or straw mats should be placed over the greenhouse film at night for warmth, and removed promptly after sunrise during the day to increase sunlight exposure, raise the temperature inside, and carefully prevent freezing damage or root rot. During the coldest days of winter, if the maximum temperature inside the shelter is below 10°C, the covering insulation materials should not be removed during the day either, so as to help strawberries overwinter safely. After the "fifth nine-day period" and "sixth nine-day period", when the outside temperature stabilises above 0°C, the paper quilts or straw mats can be removed after sunrise during the day, but they must be put back promptly before sunset in the evening to maintain a relatively high temperature inside the arched shelter. When the temperature inside the small arched shelter also remains stable above 5°C at night, the covering can be removed, and attention should be paid to weather changes at all times, with timely ventilation to prevent high-temperature damage.
II. Prevent early buds and early flowers
In the production of greenhouse strawberries, plants are prone to early budding and early flowering. If this phenomenon occurs too often, it will seriously affect the yield and quality of strawberries. The occurrence of early buds and early flowers in greenhouse strawberries is related to the following factors. First, it is related to varietal characteristics. Varieties whose flower buds differentiate easily and whose dormancy is relatively shallow, such as Lihong and Qiuxiang, need only about 50 hours of dormancy; the low-temperature requirement during the dormancy period is relatively small, so early buds are likely to appear. Second, it is related to premature flower bud differentiation caused by fertiliser and temporary planting. On the one hand, from seedling raising to flower bud differentiation, if nitrogen uptake is relatively low, strawberry flower bud differentiation often occurs earlier; on the other hand, if temporary planting is done too late, the temporary planting seedlings are too small, or aged seedlings form, or the soil in the temporary planting bed is too dry or too wet, or fertiliser is insufficient, all of these can cause strawberry flower buds to differentiate prematurely. All of these will cause early buds and early flowers in strawberries after planting. To prevent early buds and early flowers in strawberries, the following should be done in production: First, choose suitable varieties. For greenhouse cultivation, varieties with relatively shallow dormancy should be selected. If varieties with stronger dormancy are chosen, insulation covering should not be done too early. Second, during the seedling raising process, fertilise reasonably, strengthen management, and cultivate strong seedlings. By removing old leaves, removing inflorescences, straightening runners, and spraying gibberellin and other measures, strengthen the management of mother plants and produce high-quality strong seedlings. Third, pay attention to temperature control after covering the greenhouse. Keep the temperature inside below 25°C during the day and above 0°C at night. In severe winter, ensure normal strawberry development through insulation measures such as setting up small shelters inside the greenhouse, thickening the covering, and erecting windbreaks. For plants that have already developed early buds and early flowers, promptly remove the flower buds, strengthen fertiliser and water management, and promote axillary buds to flower and fruit to reduce losses.
Image: Greenhouse strawberry cultivation
III. Strengthen fertiliser and water management
Greenhouse strawberries have a long fruiting period, so on the basis of heavy base fertiliser application, top-dressing should be done reasonably to meet their nutritional requirements. Top-dressing follows the principle of "small amounts, many times". From covering the greenhouse to bud emergence, fertiliser can be applied about once every 10 days along with shallow watering, applying 10 kg of urea, 5-8 kg of calcium superphosphate and 5-8 kg of potassium chloride per mu each time. In addition, in the middle and late stages, combined with pesticide spraying, multi-element micro-fertiliser or organic nutrient solutions such as Zhibaosu can be sprayed on the leaves to increase strawberry fruit weight and sugar content. If the temperature inside the greenhouse is too high and soil moisture evaporation is large, irrigation should be done in time. In the early stage, when the outside temperature is high, irrigation should be carried out in the evening; in the later stage, when temperatures inside and outside the greenhouse are both relatively low, irrigation should be carried out in the morning. After irrigation, first raise the greenhouse temperature, then increase ventilation to lower humidity. Do not water too frequently, and each watering should soak through. Stop watering 1 week before flowering, and water once 15 days after flowering combined with fertilisation.
IV. Prevent deformed fruits
Mixing some varieties with a large amount of pollen into the main planted varieties is an effective measure to prevent deformed fruits in greenhouse strawberries. The local main variety is Baojiaozaosheng, and the pollinating varieties are Chunxiang, Fengxiang and others, generally planted at 5%-10%. Pesticides must not be sprayed during the strawberry flowering period, to prevent a reduction in pollen germination rate, which affects fertilisation and produces deformed fruits. Pesticides can be used before strawberry flowering to control diseases. After flowering, promptly remove diseased plants, remove diseased leaves and inflorescences, and control the spread of disease. When soil moisture is insufficient, promptly carry out dark irrigation under plastic film between ridges. When fertiliser is lacking, apply 15 kg of 45% ternary compound fertiliser per mu combined with watering; do not apply ammonium bicarbonate. Diluting fertiliser with water and applying it by punching holes gives better results, as this can use water to promote fertiliser uptake and meet the needs of normal strawberry flowering and fruiting. When each batch of flower buds forms in greenhouse strawberries, place bees inside the greenhouse, stocking 5000 bees per standard greenhouse, so that the pollination rate can reach 100%. The bee release times are 8-9 am and 3-4 pm.
Image: Greenhouse strawberry cultivation
V. Prevent and control pests and diseases
When using small arched shelters to cultivate strawberries, because the temperature is high and humidity is high in the small environment inside, diseases such as powdery mildew and grey mould, as well as underground pests, can very easily harm strawberry plants. For insect pests, before planting, 25% phoxim can be mixed with water or fine soil and spread into the soil, or trichlorfon powder can be spread into the soil for control. For diseases, after mulching, promptly spray 40% thiophanate-methyl 300-400 times solution or 240 times Bordeaux mixture.
[Editor's Conclusion]In order to obtain greater economic returns and achieve high quality and high yield, doing a good job in management during greenhouse strawberry cultivation is the key point. The above has introduced the key points of greenhouse strawberry cultivation techniques for everyone, and we hope it will be helpful to you!
How to Grow Greenhouse Strawberries? Greenhouse Strawberry Cultivation Techniques
Strawberry is a plant very suitable for greenhouse cultivation. Under suitable temperature, humidity and light, strawberries can have the best sweetness and flavour, and greenhouse cultivation can easily satisfy these conditions. At the same time, greenhouse-grown strawberries also have the characteristics of a short cycle and good quality. So, how do you grow greenhouse strawberries? Below is an introduction to greenhouse strawberry cultivation techniques. Let's learn about them together.
Image: Greenhouse strawberry cultivation
I. Cultivate strong seedlings
Choose a field with convenient irrigation and drainage, fertile soil, and no previous strawberry cultivation. Deep ploughing before overwintering can improve soil properties and reduce the occurrence of pests and diseases. After the seedling propagation field is selected, apply sufficient base fertiliser, prepare irrigation and drainage facilities, and apply insecticide to the soil before planting to prevent underground pests from damaging the roots. Choose plants with robust growth, good productivity, and fruit shape and quality conforming to the varietal characteristics, and use the runner seedlings they produce as mother plants for seedling propagation. In autumn, temporarily plant them in the field at a spacing of about 20 cm between plants and rows. In the following year, when the daily average temperature is above 12°C, plant the mother plants in a dedicated seedling propagation field. If tissue-cultured seedlings or virus-free seedlings are used as mother plants, better results will be obtained. The standards for strong seedlings selected for protected cultivation are generally: well-developed root system, with more than 25 first-order lateral roots; short and thick petioles, about 15 cm long and about 3 cm wide; 5-7 mature leaves; new stem thickness above 1 cm; seedling weight 25-40 g per plant; early flower bud differentiation and good development; no pests or diseases.
II. Land preparation and transplanting
Prepare the land and make beds. Generally apply 75 t/ha of decomposed chicken manure, 300 kg/ha of diammonium phosphate, and 75 kg/ha of biological potassium fertiliser. Combine fertilisation with deep ploughing of the land; then make high beds with a bed surface width of 50-60 cm, a bed ditch top width of 40-50 cm, a bottom width of 20 cm, and a height of 15-20 cm, oriented north-south. Choose loam or sandy loam plots with convenient irrigation and drainage, thoroughly remove weeds, deeply plough the field, and control underground pests. The ploughing depth is 20-30 cm. Combine ploughing with sufficient base fertiliser application; more than 75 t/ha of high-quality pigsty manure and 600-750 kg/ha of three-element compound fertiliser can be applied. Then make high ridges with a ridge top width of 30 cm, ridge bottom width of 60 cm, ridge height of 30 cm, and ditch width of 30 cm. After preparing the beds, spray and disinfect the planting holes and surrounding soil with 70% thiophanate-methyl 1000 times solution. Generally from early August to early September, choose cloudy or light rainy days for transplanting, avoiding the hot noon of clear days as much as possible to prevent seedling scorching. Before transplanting, spray 50% butachlor 3 kg/ha mixed with 900 kg of water to control weeds. Cover the ridge surface with black film, plant 2 rows per ridge, with a plant spacing of 18-20 cm, planting 105,000-120,000 plants/ha.
Image: Greenhouse strawberry cultivation
III. Fertiliser and water management
Protected cultivation of strawberries uses high-ridge planting, so intertillage is generally not needed. The timing of plastic film mulching should be determined according to the climatic environment and cultivation requirements. For overwintering and cold protection, generally water thoroughly with freezing water before the soil freezes, and cover after 3-5 d when the surface is slightly dry (mid-to-late November). If the main purpose is to raise ground temperature, transparent film should be used; if the main purpose is to control weeds, black film should be used. The film thickness is generally 0.008-0.020 mm. Combine intertillage or autumn application of organic fertiliser with soil banking, and the thickness of the soil bank should be such that the seedling heart is exposed. Strawberry growth must have sufficient nutrient supply. Base fertiliser is mainly organic fertiliser and should be applied before planting. Because strawberry planting density is high and supplemental fertilisation during the growing period is relatively inconvenient, it is best to apply enough base fertiliser at one time. Generally apply no less than 30 t/ha of chicken manure or no less than 75 t/ha of high-quality barnyard manure, and an appropriate amount of phosphorus and potassium fertiliser can be added. Organic fertiliser should be decomposed and then evenly broadcast. Top-dressing follows the principle of "small amounts, many times", mainly using quick-acting fertiliser, and adhering to the principle of moderate nitrogen and increased phosphorus and potassium. Generally from covering the greenhouse to visible buds, apply fertiliser once about every 10 d, mainly compound fertiliser (15-15-15), at a rate of 300 kg/ha. Usually in the middle and late stages, combined with pesticide spraying, spray on the leaves 0.3%-0.5% urea, 0.3%-0.5% potassium dihydrogen phosphate, 0.1%-0.3% boric acid, 0.03% manganese sulfate, 0.01% ammonium molybdate, multi-element micro-fertiliser, or organic nutrient solutions such as Zhibaosu, to promote good fruit development in the middle and late stages and increase fruit weight and sugar content. Foliar top-dressing is most needed at the visible bud stage, flowering stage and flower bud differentiation stage. The best spraying time is 16:00-17:00. During seedling raising and after planting, more water is needed, so irrigate in a timely and appropriate amount; in early spring, as long as it is not too dry, irrigation can be appropriately delayed, and irrigation should not be too heavy; in late autumn, water should be appropriately controlled to prevent excessive vegetative growth, which is unfavourable for overwintering; before the soil freezes, irrigate once with freezing water to help strawberries overwinter safely; after covering the greenhouse, the soil easily becomes short of water. About 1 week before flowering, stop watering; after flowering, water combined with fertilisation; during the fruit swelling period, special attention should be paid to irrigation. Strawberries are particularly suitable for drip irrigation, and where conditions permit, drip irrigation is best. During drip irrigation, never let water soak the fruit, to prevent fruit rot and contamination.
IV. Plant management
After greenhouse strawberries are kept warm, plant growth accelerates. Promptly remove tillers and runners; generally keep at most 1-2 relatively robust tillers per plant; promptly remove old, declining and diseased leaves. Gibberellin treatment is generally carried out about 7 d after the greenhouse is covered with film (under sunny weather conditions). For the Fengxiang variety, the concentration is generally kept at about 7 mg/kg, and the amount used is 10-12 kg of solution per standard greenhouse. Choose sunny weather for spraying. If the plant growth condition has not yet improved significantly after spraying, spray once more at the visible bud stage. Strawberry has a corymbose inflorescence with many flowers, so bud thinning and flower thinning should be done as early as possible. This is generally carried out after flowering, mainly retaining grade 1, grade 2 and grade 3 flowers, and first removing grade 4 and grade 5 flower buds, black flowers (frost-damaged flowers) and severely deformed fruits. Generally, 6-7 fruits are retained on the terminal inflorescence of each strawberry plant, and the number of fruits retained on subsequent inflorescences depends on growth and harvesting conditions. No more than 15 fruits of different sizes should be borne at the same time. Combined with bud thinning and flower thinning, promptly remove old leaves and inflorescence stalks after harvesting.
Image: Greenhouse strawberry cultivation
V. Prevention and control of diseases, insects and rodents
Promptly remove diseased leaves, diseased fruits and dead old leaves, pull out diseased plants, burn them in a centralised manner, clean up the field, and keep the small arched shelter clean and ventilated. Strawberry diseases mainly include grey mould and powdery mildew. For grey mould, spray 50% procymidone wettable powder 2000 times solution, or 50% iprodione 2000 times solution. For powdery mildew, spray 10% difenoconazole water-soluble granules 1500-2000 times solution. Insect pests mainly include aphids, red spiders, cutworms, white grubs, mole crickets and ants. For underground pests, soil chemical treatment can be carried out during land preparation. For white grubs and cutworms, use 90% trichlorfon 450 g/ha mixed with 8250 kg of water for root drenching. For aphids, red spiders and others, spray 10% imidacloprid 1500 times solution. For field mice, use 7.5% coumatetralyl rodenticide prepared as poisoned bait.
VI. Harvest at the right time
When the fruit turns from green to milky white, the entire fruit shoulder and fruit base have all turned red, the appearance is bright and colourful, and the fruit is richly aromatic, this is the suitable harvest period, and the fruit quality is at its best. If long-distance transport and sale are needed, the strawberries can be picked and shipped when 80% ripe. Varieties with fine, dense flesh can be harvested when nearly fully ripe. When picking the fruit, remove it together with the fruit stalk. The best picking time each day is after the dew has dried and before the heat arrives.
[Editor's Conclusion]Strawberries have high nutritional value and health benefits, and are deeply welcomed by the market. Using greenhouse techniques to grow strawberries can meet market demand while also effectively improving strawberry quality and bringing better economic returns. The above has introduced greenhouse strawberry cultivation techniques for everyone, and we hope it will be helpful to you!