Four-Season Strawberry Cultivation Techniques and Key Points of Growing Management

Four-season strawberries grown in the open field are planted at the end of September, sprout in mid-March of the following year, and begin flowering in late March. From late March they bloom and bear fruit successively, continuing until early November. In late October, as temperatures drop, greenhouse frames are covered. Combined with protected cultivation, they can flower and fruit throughout all four seasons, with essentially no obvious dormant period throughout the year. Now let us take a look at four-season strawberry cultivation techniques together!

Site Selection for a Four-Season Strawberry Orchard

Four-season strawberries like fertilizer, water and light, but fear waterlogging and drought. Therefore, a site with ample sunlight, level ground, fertile and loose soil, and good drainage and irrigation should be chosen for establishing the orchard, with sandy loam or neutral soil and a pH of 5.5-6.5 being most suitable. For clay loam, it is best to apply more organic fertilizer or improve it with added sand before planting. Before planting, apply 3000-5000 kg of well-rotted high-quality organic fertilizer per mu, along with 50 kg of compound fertilizer. After fertilizing, plow about 30 cm deep, allow the fertilizer and soil to mix thoroughly, rake level, let settle, and then form beds or ridges.

Four-Season Strawberry Planting Techniques

1. Flat bed planting: To make watering and management easier, beds should not be too long or too wide. Generally beds are 1.2-1.5 m wide (planting 3-4 rows) and 10-20 m long, with bed ridges 15 cm high. After the beds are prepared, rake them level and wait to plant.

2. Ridge planting: In low-lying land, plots with poor drainage, and protected cultivation in winter, ridge planting can be used. Ridges are 15-20 cm high, with a top width of 40-50 cm (planting 2 rows) and a bottom width of 60-70 cm, with furrows 15-20 cm wide between ridges. After making the beds and ridges, irrigate lightly once or press appropriately so the soil settles.

3. Planting time: Four-season strawberries are generally planted in spring or autumn, and can also be planted in winter using winter-warm greenhouses. Spring planting is generally from mid-to-late March to early April, and autumn planting from mid-to-late August to mid-to-late October.

4. Planting density: Four-season strawberry plots should maintain good ventilation and light conditions and a relatively large soil area, so as to achieve high yield, good quality and large fruit. Planting should not be too dense. Plant spacing should be kept at 30-40 cm × 40-50 cm, using triangular planting, with 8000-11000 plants per mu. The planting depth should follow the principle of "shallow enough not to expose roots, deep enough not to bury the crown."

Post-Planting Management of Four-Season Strawberries

1. Field weeding: Weeds compete with strawberries for water, light and nutrients, causing reduced yield and lower quality. Therefore, weed control is an important guarantee for producing high-quality large-fruit strawberries. Field weeding can use integrated measures such as manual weeding, mulching film to suppress weeds, and crop rotation. To reduce labor, herbicides can also be used for weed control.

2. Fertilizer and water management: During the growing season, four-season strawberries need multiple soil topdressings and foliar sprays. Soil topdressing is generally applied 4-6 times per year, each time with about 50 kg of compound fertilizer or multi-element compound fertilizer per mu. When applying, spread the fertilizer evenly in the strawberry beds, and water promptly after topdressing. Never scatter fertilizer into the crown of the strawberry, to avoid burning young leaves. Foliar spraying is done about once every 20 days, mainly with nitrogen-phosphorus-potassium compound fertilizer at a concentration of 0.2-0.3%. After each topdressing, water promptly. In dry years, water more often during the growing season, keeping soil moisture at 70-80% of field maximum water-holding capacity. Strawberries are not tolerant of waterlogging, so pay attention to drainage during the rainy season.

3. Flower and fruit thinning: Four-season strawberries can bloom and bear fruit about 60 days after planting. To produce high-quality large fruit with high yield and efficiency, plant strong seedlings and grow them large. Especially for seedlings planted in spring, be sure to grow the plants large and strong before letting them bear fruit. In the early stage, promptly thin out flower clusters and runners, and only retain flowers and fruit after the plant canopy reaches 30-40 cm. Alternatively, plant seedlings in spring, strengthen cultivation and management, and let them fruit in late summer and early autumn, achieving both large, high-quality fruit and high yield and efficiency. At each flowering period, retain 4-5 early, large flowers and remove small and late flowers. The earlier the flower thinning, the better. After fruit set, thin out small and deformed fruits, retaining 3-4 large fruits per plant each time. After the previous fruits mature, select and retain another 4-5 large flowers to maintain continuous flowering and fruiting.

4. Reasonable pruning: To reduce nutrient consumption and ensure high yield and continuous fruiting, runners must be continually removed during the growing season. Removing runners early can increase strawberry yield by about 20%. Four-season strawberries grow new leaves and differentiate new stems throughout all four seasons, so during the entire growing season, lower old leaves must be continually removed to promote the growth of upper new leaves and new stems. Old leaves can generally be removed from the base of the petiole once the petiole begins to yellow and changes from upright to flat.

5. Fruit straw padding: As fruits enlarge, the inflorescences gradually droop and touch the ground, becoming easily contaminated by soil, which affects coloring and quality and easily causes fruit rot. In strawberry orchards without plastic film mulching, 2-3 weeks after flowering, spread straw between the strawberry plants to cushion beneath the fruit, or arrange straw into rings and place the fruit on the straw rings.

6. Winter management: As long as the temperature is suitable, four-season strawberries can bloom and fruit year-round. Therefore, in production, they can be grown in the open field in spring, summer and autumn. In mid-to-late October, when the temperature drops to 5-7°C, cover the greenhouse promptly to ensure continuous flowering and fruiting. Management inside the greenhouse is the same as for ordinary strawberries.

6. Timely renewal: Under ordinary management conditions, growth begins to decline from the 3rd year after planting, with reduced yield, lower quality, frequent pest and disease occurrence, and decreased economic returns. To ensure that four-season strawberries both continue flowering and fruiting and achieve high yield, high quality and high efficiency, renewal is generally required every 2-3 years. For open-field cultivation, replanting once every two years is more suitable.

Disease Control of Four-Season Strawberries

Leaf Spot

[Symptoms] Leaf spot, also called snake-eye spot, mainly damages leaves, petioles, fruit stalks, young stems and seeds. Dark purple small spots form on the leaves and, after expanding, become nearly round or oval lesions with purplish-red-brown edges and grayish-white centers, slightly showing fine rings, making the entire lesion look like a snake eye. No small black grains form on the lesions.

[Control] Promptly remove diseased and old leaves. In the early stage of the disease, spray with 70% chlorothalonil wettable powder at 500-700 times dilution, then spray again after ten days. Or use 70% mancozeb wettable powder, 200 g per mu mixed with 75 kg of water for spraying.

2. Powdery Mildew

[Symptoms] Powdery mildew mainly damages leaves, and also infects flowers, fruits, fruit stalks and petioles. Leaves curl upward into a spoon shape. When flower buds and petals are damaged, they turn purplish-red and cannot bloom or bloom fully; fruits do not enlarge, becoming slender, and young fruits lose their luster and harden. If strawberries are damaged near ripening, they lose commercial value.

[Control] On the central diseased plants and around them, focus on spraying 0.3 degree Baumé lime sulfur mixture. After harvest, cut all leaves in the orchard and spray 70% thiophanate-methyl at 1000 times dilution, or 50% Tuzet at 800 times dilution, or 30% triflumizole at 5000 times dilution, etc.

3. Gray Mold

[Symptoms] Gray mold is the main disease after flowering and can occur on flowers, petals, fruits and leaves. On enlarging fruits, brown spots form and gradually expand, densely covered with gray mold, causing the fruits to soften and rot, seriously affecting yield.

[Control] Apply from the bud stage to the flowering stage by spraying 25% carbendazim wettable powder at 300 times dilution, 50% captan wettable powder at 800 times dilution, or 50% iprodione at 500-700 times dilution, etc.

4. Root Rot

[Symptoms] Starting from the lower leaves, leaf margins turn reddish-brown and gradually wilt upward until death. The stele begins to turn dark brown and rot in the middle, and the central column of the root turns red.

[Control] Before transplanting strawberries, pour 40% asparagus green powder at 600 times dilution onto the bed surface, then cover with soil, level and transplant, so as to effectively kill pathogens in the soil, lower the base number of inoculum in the field, and reduce chances of infection.

5. Verticillium Wilt

[Symptoms] Verticillium wilt is a soilborne disease. The main symptoms are deformed young leaves, yellowing leaves, and extremely rough leaf surfaces. Subsequently, leaf margins turn brown and wilt inward until death.

[Control] Strictly introduce disease-free plants for planting, shorten the renewal period, and use 13.5-20 liters of chloropicrin or solar film covering with irrigation for soil disinfection. Diseased plants must be pulled out and burned.

Passion Fruit Cultivation Techniques and Key Points of Growing Management

Passion fruit, also known as egg fruit, is a tropical and subtropical perennial evergreen vine of the passionflower family, native to southern Brazil. Its leaves are oddly shaped, its flowers brightly colored, and it stays green all year round. Its fruit is an oval berry, with single fruit weight of 60-120 g. The juice is clear yellow and fragrant, with the rich aroma of more than ten kinds of fruit such as pomegranate, pineapple, strawberry, lemon, mango and sour plum, and a distinctive flavor, which is why it is named passion fruit. Passion fruit is rich in protein, fat and niacin, and also contains sugars, vitamins, and various compounds such as phosphorus, calcium, iron and potassium, as well as 17 amino acids, making it highly nutritious. Passion fruit has long been known as the "king of beverages." Its juice can be processed into pure natural high-quality drinks that are not only uniquely flavored and nutritious, but also nourishing and healthful and helpful for digestion, and are in short supply on the market. It can also be processed into fruit syrup, jam, jelly and preserved fruit. The whole passion fruit plant is treasure: the seeds contain 25% oil, and the oil quality is comparable to sunflower oil and suitable for edible oil; the pectin extracted from the peel is a good stabilizer and thickener for food processing; the roots, stems and leaves can all be used medicinally, with effects such as reducing inflammation and pain, promoting blood circulation and strengthening the body, and lowering lipids and blood pressure; the essence extracted from passion fruit is a good additive for pastries and alcoholic drinks.

The passion fruit planting industry and processing industry are in the ascendant and have great development potential. Passion fruit planted in the current year bears fruit in the same year, with about 110 jin of fruit per plant, and an income of about 10,000 yuan per mu, and can yield continuously for ten years. Therefore, growing passion fruit is a path to wealth with low investment and quick returns.

Environmental Requirements

1. Temperature. The most suitable growth temperature for passion fruit is 20°C-30°C. It generally grows well at temperatures not lower than 0°C, and at -2°C the plant will be severely damaged or even die. Areas with an annual average temperature above 18°C are most suitable for planting.

2. Water. Passion fruit grows best under conditions with annual rainfall of 1500-2000 mm that is evenly distributed. For commercial development planting areas, annual rainfall should not be less than 1000 mm.

3. Light. As a tropical fruit, passion fruit likes ample sunlight to promote vine growth and nutrient accumulation. Long-day conditions are favorable for passion fruit flowering. In areas with 2300-2800 annual sunshine hours, passion fruit has good vegetative growth, more nutrient accumulation, fast vine growth, early fruiting and high yield.

4. Soil. Passion fruit has strong adaptability and does not demand much from the soil. However, for large-scale production, the soil layer should be at least 0.5 m deep, and the soil should be fertile, loose and well-drained, with a soil pH of 5.5-6.5 being suitable.

Variety Selection

The passion fruits widely planted at present include purple passion fruit, yellow passion fruit and hybrids, etc., but the fruit set rate under natural pollination is about 10%-29.6%, so artificial pollination is needed. The purplish-red passion fruit introduced from Hawaii, USA, has a natural pollination fruit set rate of 60%, and also has high sugar content (14.4%-21.9%) and vitamin C (49 mg per 100 g of pulp), strong aroma and high yield. It is harvested in the same year it is planted, with a yield of more than 2000 kg per mu.

Orchard Establishment

1. Site selection and land clearing. For passion fruit development orchards, choose areas with relatively convenient transportation, facing the sun and sheltered from the wind, and with a relatively thick soil layer. The land can be gentle sloping land, terraced land or flat land, and requires deep, relatively fertile soil with good drainage, preferably with irrigation conditions. Deep, fertile and loose sandy loam is more suitable. Heavy clay soil, compacted sandy soil, cold sandy soil and places prone to erosion are not suitable for planting, or may be planted after improvement. Full clearing or hole clearing can be used. For concentrated contiguous orchards, convert sloping land into terraced land, with a bed surface width of more than 1.1 m, sloping inward, and build a small ridge 20 cm high and 30 cm wide along the outer edge of the planting belt. Also plan the orchard drainage and irrigation and road systems at the same time.

2. Trellising. Passion fruit is a climbing plant and depends on trellis support for normal growth. Trellis types include flat-top trellis, upright fence type, ""-shaped and ""-shaped fence type, etc. Generally the trellis height should be 1.8-2 m, and trellis materials can be cement posts, stone posts, wooden posts, bamboo poles, wooden poles, iron wire, etc.

3. Digging holes. Planting holes are spaced 4×5 m, with 25 plants per mu. Holes are 60×60×60 (cm) deep. Apply 25 kg of farmyard manure and 0.5 kg of phosphate fertilizer per hole as base fertilizer.

4. Planting. Passion fruit can be planted throughout all four seasons, but spring and autumn are most suitable. Planting should be done on cloudy days or sunny days after rain. When planting seedlings, properly prune old leaves, and take the seedlings out of the nursery bags by breaking the bags; do not bury the bags in the soil. When setting the seedlings, mix an appropriate amount of rotted organic fertilizer with sandy loam evenly to use as planting soil or covering soil. When planting, straighten the root system, fill soil in layers, and press firmly. Water the roots promptly after planting. For newly dug planting holes, when planting, the seedling root crown should be slightly 8-10 cm above ground level. After planting, form a tree basin and cover with grass or film to keep warm and retain moisture.

Orchard Management

1. Fertilization. For newly planted passion fruit, nitrogen fertilizer is mainly used in the early stage to promote plant growth. The root system begins to grow 10-15 days after planting, and 0.5% dilute urea or dilute human manure and urine can be applied, then once every 20 days thereafter, with 5 kg of rotted human manure and urine or 0.1 kg of compound fertilizer per plant each time. Apply 20-30 kg of farmyard manure, 0.6-0.7 kg of urea, 0.6-0.9 kg of phosphate fertilizer and 1.2-1.3 kg of potassium fertilizer per plant each year. Farmyard manure and phosphate fertilizer should be composted and rotted, then applied in furrows around the Beginning of Spring. Urea and potassium fertilizer should be applied once a month during the flowering and fruiting period, with 0.3-0.4 kg of mixed fertilizer per plant.

2. Irrigation. Passion fruit is a shallow-rooted plant and likes moisture, but is both averse to waterlogging and afraid of drought. Therefore, first open drainage ditches well to prevent water accumulation in the orchard; at the same time, spread weeds to retain water, and consider irrigating once if there is no soaking rain for 15 days.

3. Soil management. After winter orchard clearing, plow the whole orchard, incorporating the cleared weeds and fallen leaves and twigs into the soil while plowing. Then broadcast 25-30 kg of lime per mu.

Tree Training

1. Training and trellising. After young seedlings resume growth, remove buds once every 5 days to promote rapid and thick growth of the main vine. When the main vine grows to 40-50 cm, insert supports promptly to guide the main vine onto the trellis. After the main vine is on the trellis, frequently guide the side vines to grow in a spiral around the wire trellis. After the side vines fill the trellis, top them and tie them. The side vines should run one branch per side, which helps fruiting branches fill the trellis sooner.

2. Training young trees. Use the single main vine, double-layer, four-main-branch training method. When the main vine grows to 70-80 cm, retain 2 side vines and guide them separately onto the trellis as the first layer of main vines. When the plant grows to 150-160 cm, retain another strong side branch, which together with the extended main vine serves as the second layer of main branches, guiding them in opposite directions onto the trellis, forming a double-layer, four-branch training structure. During this period, all side branches and sprouting branches below 80 cm on the main vine and between 80-160 cm should be pruned off or removed.

3. Training old trees. For shoots sprouting after fruit harvest in the previous year, fruit vines are almost always produced at the nodes above the middle. As many fruiting mother branches as possible should be retained in the previous year, but to prevent the trellis surface from becoming too dense, prune as early as possible after harvest. Keep vines according to 2 main branches. Branches near the trunk bear full fruit first, and immediately after the mature fruit is harvested, prune back to 2-3 nodes. Buds sprouting again from the base of the main branches can form new fruiting branches. After the last batch of fruit is harvested in winter, all fruiting branches are pruned from the base.

Pest and Disease Control

1. Main diseases and control. The main diseases include damping-off at the seedling stage, mosaic disease, phytophthora blight and stem base rot. The control methods are as follows:

① Choose clean soil for raising seedlings, maintain field moisture, especially prevent the soil from becoming too wet, keep away from bananas, various cucurbits and solanaceous vegetables, and promptly remove and burn diseased plants and diseased leaves.

② Chemical control: Use 0.5% Bordeaux mixture, or phosphethyll aluminum, ridomil, 1000 times dilution of kangkuling, 800 times dilution of 75% chlorothalonil, or 1000 times dilution of 50% carbendazim wettable powder for control.

2. Main insect pests and control. The main insect pests include fruit flies, mites and scale insects. Use 800 times dilution of 90% trichlorfon, 1000 times dilution of Nongdile, 800 times dilution of Lorsban, or 2000 times dilution of Miejisi, etc. for control.

Timely Harvest

Generally harvest 10 days before fruit drop, when the fruit color turns purple (purple varieties), yellow (yellow varieties) or red (red varieties) and has a slight fragrance, but fresh fallen fruit can also be picked up from the ground.

Strawberry Pot Cultivation Techniques and Key Points of Growing Management

Strawberries need to be grown in a sunny, warm environment. In addition, the soil must have good water permeability. If planting in the ground, be careful not to use land that previously grew potatoes, because strawberries are easily infected by a pathogen from potatoes. When strawberries bear fruit, the fruit needs to be separated from the soil, so growing strawberries in flower pots is a relatively good choice. You can choose a multi-purpose flower pot and spread a layer of stones on the surface of the soil in the pot, so that when watering, mud is less likely to splash onto the strawberries. If planting in soil, you can use some dry grass or a mat to protect the strawberries.

Selection of Pots, Soil and Varieties

For pot cultivation, it is advisable to choose ceramic pots with a diameter of 20-30 cm. Use soil with relatively high humus content for the pot soil. For varieties, it is better to use excellent four-season strawberry varieties such as European Four-Season Red, Changhong No. 2 and 83-38 for pot cultivation. They can bloom and fruit multiple times throughout the year.

Cultivation Techniques

Pot cultivation can be done throughout all four seasons. However, when taking seedlings from the field and potting them, it is best to do so in autumn. Choose robust seedlings, take them with more soil when lifting, remove old and damaged leaves, and cut the seedling roots to about 10 cm. Let the root system spread out and plant into the pot soil. The planting depth should follow the principle of not exposing roots and not burying the crown. Press the soil firmly, fix the seedling position, and keep the soil surface 3-4 cm below the pot rim. After planting, water thoroughly, place in a shaded place for 3-5 days, then move to a place with ample light.

Fertilizer and Water Management

Four-season strawberries bloom and fruit multiple times a year and consume much nutrition, so nutrient supplementation should be strengthened. You can use animal hooves, fish bones, poultry offal, soybean cake, etc., add water, let them rot and ferment, and compost them into liquid fertilizer water, or topdress with compound fertilizer. Generally topdress once a week. For outdoor pot cultivation, water once each morning and evening. When watering, the water should be warmed in the sun first; never directly irrigate with well water or tap water.

Seedling Management

Pot-grown strawberries should have strengthened plant management. First, thin buds, remove leaves and remove runners at the right time. That is, appropriately thin out ineffective high-level flowers during the bud dispersal stage. Remove old leaves, residual leaves, diseased leaves and excess runners to reduce nutrient consumption and improve fruit quality. Second, shape the fruit with supports. That is, use iron wire or bamboo sticks to make fruit supports of different shapes, place them in the flower pot to prop up the fruit clusters, promote ventilation and light penetration for the fruit clusters, make fruit color evenly, prevent soil from contaminating the fruit, and reduce pest and disease damage. At the same time, runners can also be used for artistic shaping to increase ornamental value. Third, corresponding integrated control measures should be used to prevent and control pests and diseases.

Repotting

After pot-grown strawberries have fruited for 2 years, they should be repotted or the pot soil changed after fruiting. When repotting, first take the plant out of the pot, cut off aged roots, dead roots and lower aged rhizomes, then plant into new pot soil.

Temperature and Humidity

Generally, pot-grown strawberries require a temperature of 20-25°C, and in winter the room temperature should be kept above 15°C. The flower pot should be placed in a ventilated, sunny place, and the pot soil should be kept moist regularly.