Efficient cultivation techniques for Chinese toon (Toona sinensis): How to do open-air, greenhouse and soilless cultivation separately?
Because the tender leaves of Chinese toon are eaten as a vegetable, and their taste and nutritional value are excellent, in recent years demand has exceeded supply in the market while the planting range has also expanded. So what are the efficient cultivation techniques for Chinese toon? How are open-air, greenhouse and soilless cultivation each carried out?
1. Efficient open-air cultivation techniques for Chinese toon
Chinese toon is a fast-growing broadleaf tree species, so a nursery site should be chosen that is sheltered from the wind and faces the sun, has good drainage and irrigation, flat terrain, convenient transport, deep and moist soil layers, and fertile sandy loam or loam soil; places with many underground pests are not suitable as nursery sites.
1. Seed collection
(1) Select superior trees aged 15-30 years with straight and full trunk form, a large crown, glossy leaves, a rich fragrance, vigorous growth and no pests or diseases for seed collection.
(2) After the fruits are collected, put them in the sun to dry until the valves split open, then turn them over to take out the seeds, but they must not be exposed to strong sun, otherwise the seed germination capacity will be reduced.
(3) After the seeds are dried in the shade, put them in bags and store them indoors in a ventilated and dry place; generally they can be stored for 5-6 months.
2. Germination promotion
(1) First rub off the membranous wings of the seeds by hand, then soak the seeds in warm water at 40-50°C for 4-5 hours, then rinse once with warm water, and then wrap the seeds in cotton and place them in an environment of about 25°C to promote germination.
(2) During germination promotion, rinse the seeds once a day with warm water at 25-30°C to remove harmful substances secreted by the seeds; when 30-40% of the seeds have sprouted, they can be sown.
3. Sowing
Sow from March to April each year. For field seedling raising, build raised beds with a bed surface width of 1.0-1.5 m and a height of 15-30 cm, and a path width of 40-60 cm. After forming the beds, cover the bed surface with yellow subsoil or burned soil about 3 cm thick.
4. Land preparation
(1) Chinese toon is relatively tolerant of moisture, so sandy loam woodland with deep, moist and fertile soil layers can be selected, with a soil pH of 5.5-8.0.
(2) Clear weeds, shrubs and logging residues and burn them. On gentle slopes, the land can be fully cleared and prepared to a depth of 15-20 cm.
(3) Planting density depends on the purpose of growing the trees; for those grown mainly for terminal buds and tender leaves, proper close planting should be used, with a row spacing of 2 m × 2 m and hole specifications of 60 cm × 60 cm × 30 cm. Apply base fertilizer in the holes, mainly phosphate fertilizer, organic fertilizer and compound fertilizer, and backfill part of the topsoil and subsoil before planting.
5. Planting
(1) Lift the seedlings during the dormant period before sprouting in early spring; 2-3 days before lifting, water thoroughly to keep the soil moist.
(2) Use lifting tools when lifting seedlings and take care to keep the root system intact. Grade the seedlings and plant them as soon as they are lifted.
(3) Bare-root seedlings should be dipped in yellow mud slurry before planting; when planting, hold the seedlings upright and carefully press the soil firm with both hands.
6. Fertilization
(1) During the seedling growth period, apply fertilizer lightly and frequently, mainly organic fertilizer.
(2) During the fast-growing period, appropriately increase the application of chemical fertilizers, such as ammonium sulfate and urea.
(3) After September, water and fertilizer supply should be controlled; phosphorus and potassium fertilizers can be applied to enhance the lignification degree of the seedlings, improve their stress resistance, and do a good job of cold protection for overwintering. With proper management, one-year-old field seedlings can reach a height of 70 cm and a ground diameter of 0.8 cm.
2. Efficient greenhouse cultivation techniques for Chinese toon
1. Regulate temperature, humidity and light
(1) Temperature regulation
According to observation, when the shed temperature is about 25°C, the tender buds can grow 3—4 cm in 24 hours; at 15°C, they grow only 1 cm; when the shed temperature exceeds 35°C, it affects the coloring and quality of the toon buds. The 10—15 days after covering with film is the seedling recovery period, when efforts should be made to raise the air temperature, and the daytime shed temperature can be about 30°C. After more than 1 month of natural light and temperature accumulation, after the buds sprout, the daytime temperature should be controlled at 25—30°C and the nighttime temperature at 13—17°C; during the bud harvesting period, the air temperature should preferably be 18—25°C. Depending on conditions, cover with straw mats or paper quilts to increase or maintain temperature.
(2) Temperature regulation
Seedlings planted in the warm shed have poor root water absorption capacity, so relatively high soil moisture and air humidity should be maintained at the initial stage; after planting, water thoroughly, and afterward water lightly as conditions require. Keep the relative air humidity above 85%, and on sunny days also spray water on the seedlings to prevent water loss and drying out. After sprouting, the relative air humidity should preferably be 70%; if humidity is too high, not only will sprouting be delayed, but the fragrance will also be greatly reduced, so ventilation should be provided in time to remove moisture.
(3) Light regulation
Chinese toon likes light, so drip-free film should be used as much as possible; during the day, uncover the straw mats and paper quilts in time, and also often clean off debris on the film to increase light; if the light is too strong, cover appropriately with straw for shading.
2. Pinching to promote branching
When harvesting the 2nd crop of Chinese toon, remove the top at the same time to determine the trunk (pinch at 40 cm above the ground). After determining the trunk, spray 15% paclobutrazol solution at a concentration of 200—500 ppm to control apical dominance, promote rapid branch growth, and achieve dwarfed cultivation. After that, according to the development of the tree shape, pinch and prune in time to ensure many branches in the crown and more toon bud production, achieving high yield and quality.
3. Water and fertilizer management
Chinese toon is a fast-growing woody vegetable, with a modest water requirement, and has a relatively high demand for potassium fertilizer; for every 300 sq m of warm shed, the base fertilizer requires about 2500 kg of fully decomposed high-quality farmyard manure, 75—150 kg of plant ash or 3—6 kg of potassium dihydrogen phosphate, and 3—6 kg of diammonium carbonate. After each harvest, according to soil fertility, the growth of Chinese toon and leaf color, apply additional fertilizer and water in appropriate amounts.
4. Put on light-blocking film bags
After Grain Rain, when the ground temperature is above 18°C, the shed film can be removed to let the saplings grow naturally. After that, although the saplings develop quickly, they tend to age easily, so black-red 2-layer 2-color polyethylene film bags should be prepared early; when the Chinese toon buds grow to 5 cm, the light-blocking film bags can be put on. This can both increase yield and ensure that the toon buds do not age. When the toon buds grow to 15 cm, harvest them together with the bags, then remove the bags for sale; this kind of film bag can be used multiple times.
5. Bud harvesting and packaging
40—60 days after covering with film, when the toon buds grow to 15 cm and are well colored, harvesting can begin. Harvesting should preferably be done in the morning and evening. The first-crop buds (that is, the buds borne at the top of the branches) have good quality and color and are top-grade, and should preferably be harvested at 12—15 cm. When the second-crop buds grow to 20 cm, harvest in time and pinch the tops to encourage the emergence of side buds and latent buds and increase yield. Generally, harvesting can be done once every 10 days; after harvesting, apply fertilizer and water as appropriate to promote the growth of toon buds.
Chinese toon buds marketed around the Spring Festival should be sorted and tied into bundles after harvesting, generally 50—100 g per bundle, put into plastic bags and sealed to prevent water loss.
3. Efficient soilless cultivation techniques for Chinese toon
Chinese toon is an early-spring delicacy, and it gives off a special fragrance of its own; many people like to eat it because of this advantage. In the past, Chinese toon eaten was wild and people picked it themselves; now large-scale planting bases have appeared, and there are certain cultivation models; soilless cultivation is a relatively novel cultivation technique in recent years, and Chinese toon can also be cultivated using this technique.
1. Site selection
Sites with protective facilities such as greenhouses, large sheds, idle workshops or single-story houses can be selected for cultivation. The indoor area can be determined according to the production scale.
2. Spraying equipment
During the production process of Chinese toon sprout vegetables, watering is not needed; atomized water supply is required, that is, the water supply must neither impact the seedlings nor allow water to accumulate in the trays. Generally, an agricultural backpack sprayer can be used, and an automated micro-spray device and timer can also be installed for automatic timed spraying.
3. Seed storage
In Chinese toon sprout vegetable cultivation, new seeds of the current year with relatively high germination rate, purity and cleanliness and plump grains should be selected; if year-round sprout vegetable production is carried out, the seeds should preferably be stored at 1-5°C to maintain a relatively high germination rate.
4. Seed treatment before sowing
High-temperature seed scalding: scald the seeds with hot water at 55-70°C. Germination-promoted sowing can be harvested 5-7 days earlier than direct sowing, and the sprouts grow vigorously, are easy to manage, and have noticeably fewer diseases.
5. Sowing
When the seed sprouts grow to 0.2-0.5 cm, they can be sown. If the sprouts are too long, they are easily damaged during sowing; if the sprouts are too short, seeds that cannot sprout are likely to be mixed in and sown together, causing seed and sprout rot after sowing, affecting the growth of the entire tray of sprouts, and at the same time prolonging the growth period of the sprout vegetables and increasing production costs.
6. Tray stacking.
The cultivation trays are stacked together, about 15-20 trays per stack; when stacking, they should be staggered with a certain gap between trays to facilitate ventilation and ensure normal respiration of the sprouts.
7. Water and fertilizer management
Chinese toon is a fast-growing woody vegetable, with a modest water requirement, and has a relatively high demand for potassium fertilizer; for every 300 sq m of warm shed, the base fertilizer requires about 2500 kg of fully decomposed high-quality farmyard manure, 75—150 kg of plant ash or 3—6 kg of potassium dihydrogen phosphate, and 3—6 kg of diammonium carbonate. After each harvest, according to soil fertility, the growth of Chinese toon and leaf color, apply additional fertilizer and water in appropriate amounts.
8. Pest control
(1) Chinese toon powdery mildew
Control method: promptly remove diseased branches and leaves and burn them. Strengthen tending management, apply fertilizer reasonably, and enhance the growth vigor and disease resistance of the tree body. Before Chinese toon sprouts, spray 1 time with 5 degrees Baume lime sulfur mixture; during the growing season, spray 2-3 times with 0.3-0.5 degrees Baume lime sulfur mixture. It is also possible to spray the branches and leaves with 2.5% triadimefon 1500-2000 times solution, or 25% sulfur suspension concentrate 200 times solution, 50% thiophanate-methyl, or 50% carbendazim 600-800 times solution. Spray 2-3 times with Baume lime sulfur mixture. It is also possible to spray the branches and leaves with 2.5% triadimefon 1500-2000 times solution, or 25% sulfur suspension concentrate 200 times solution, 50% thiophanate-methyl, or 50% carbendazim 600-800 times solution.
(2) Chinese toon dieback disease
Control method: promptly remove infected branches and trunks and burn them to reduce the source of infection. Whitewash the trunks in winter and spring. For chemical control, make small holes on the initially diseased spots deep to the xylem, then spray 70% thiophanate 200 times solution and so on for control. For reasonable pruning, apply Bordeaux mixture or lime sulfur mixture to the wounds. Strengthen fertilizer, water and tending management, enhance tree vigor, improve disease resistance, and prevent infection.