A Detailed Guide to Broccoli Planting Time and Seedling Cultivation Techniques
Broccoli originated in the coastal areas of the eastern Mediterranean. It is now cultivated in both northern and southern China and has become one of the main everyday vegetables. It is rich in nutrients, containing protein, sugars, fats, vitamins and carotene. Its nutritional content ranks first among vegetables of its kind, and it is known as the “crown of vegetables,” with excellent prospects for cultivation. Let us take a look below at the planting time for broccoli!
Broccoli Planting Time
Broccoli is usually sown in autumn, grows through winter, and comes onto the market and reaches the table normally after the Spring Festival. It begins flowering in spring, and the seeds mature in April or May. For summer and autumn seedling cultivation, seedlings are raised during the high-temperature season from August to October. At this time the temperature is generally above 25°C, sometimes reaching a high of 30-35°C, and there is also the danger of heavy rain and hail. Therefore, shade netting is used for raising seedlings in the open field. The seedling age is generally 35-40 days. Sowing or direct hole planting may be used. The seedling stage averages about 30 days, and from transplanting to harvest takes 80-90 days. The winter habit is somewhat strong; when the seedling stem reaches 10 mm in thickness it can be affected by low temperature and complete the vernalization process.
Broccoli Growing Environment
1. Light: Broccoli is not especially strict about light requirements, but during growth it prefers ample light. With sufficient light the plants grow robustly and can form a strong vegetative body, which is favorable for photosynthesis and the accumulation of nutrients, and makes the heads compact and dense with a fresh green color and good quality. In midsummer, excessively strong sunlight is also unfavorable for the growth and development of broccoli.
2. Temperature: Within the range of 5-20°C, the higher the temperature, the faster broccoli grows and develops. The optimum germination temperature is 20-25°C, and the optimum growth temperature during the seedling stage is 15-20°C. It has strong cold and heat tolerance. The optimum growth temperature during the rosette stage is 20-22°C, and the optimum temperature for head development is 15-18°C. When the temperature is above 25°C the head quality tends to deteriorate, but as long as it is not damaged by freezing, the head can still grow slowly at low temperatures of 5°C or even below.
3. Water: Broccoli has a relatively large water requirement throughout its growth process, especially during the period of vigorous leaf growth and head formation, when it must not lack water. Even short-term drought will reduce yield. Rainy conditions during the seedling stage or excessively high soil moisture easily cause diseases such as black rot and black spot. During head formation, the soil moisture must be about 70-80% of field capacity to meet growth needs.
4. Soil: Broccoli is not strict about soil conditions, but overly poor soil leads to poor plant development and low yield and quality, while excessively fertile soil causes loose heads and hollow stems. It is suitable for planting in loam and sandy loam with good drainage and irrigation, a deep plow layer, loose and fertile soil texture, and strong water and fertilizer retention. The soil pH range is 5.5-8, but 6 is best.
Broccoli Seedling Cultivation Techniques
1. Variety selection: Broccoli is a vegetable that prefers cool conditions. Choose varieties with strong plant growth vigor, dark green heads, few scorched heads, arc-shaped round heads, few side shoots, small buds, large heads, disease resistance, heat tolerance, cold tolerance and wide adaptability, such as Japan's Youxiu, Longlü and Shanshui. Other varieties such as Yuguan, Dongfang Lübao, Wanlü and Lüxiu, or various high-quality varieties selected according to market demand, may also be used, but they must meet the national second-grade seed standard before use.
2. Sowing time: For autumn double-cover cultivation, sow in early July; for overwintering cultivation in solar greenhouses, sow from late July to August; for early spring cultivation in solar greenhouses, sow from early September to early October; for early spring cultivation in plastic tunnels and small arch sheds, sow in November; for spring plastic film cultivation, sow in January.
3. Seed Treatment
① Seed soaking: Soak the seeds in warm water at 33°C for 15 minutes, stirring constantly. Stop when the water temperature drops to 20°C, then continue soaking in warm water for 4 hours. Rinse clean with clear water and then germinate.
② Germination: Wrap the soaked seeds in moist cotton gauze and germinate them at 30°C. Rinse once a day with clear water, and sow when 60% of the seeds have sprouted white.
4. Open-Field Seedling Cultivation
① Seedbed selection: The broccoli seedling stage is relatively short. Choose a seedbed on a field with high terrain, convenient drainage and irrigation, soil rich in organic matter, and where cruciferous vegetables have not been grown in the past two years or where the previous crop was rice. The seedbed should preferably run north-south.
② Apply sufficient basal fertilizer: Deep plow 15-20 days before sowing. Apply 15 kg of NPK compound fertilizer plus 5 kg of superphosphate per mu 7-10 days before sowing, or sprinkle 2500 kg of decomposed human manure, to ensure an adequate nutrient supply during the seedling stage. Turn and rake the soil finely and make a sowing bed about 1.2 m wide. The seedling field ratio is 1:20-30.
③ Mix with chemicals and sow: Before sowing, water the seedbed thoroughly once, and apply 1000-fold phoxim or similar chemicals to prevent underground pests. When sowing, mix the treated seeds evenly with an appropriate amount of sand and broadcast them uniformly in the seedbed. After sowing, press with an iron shovel, then spread a layer of medicinal soil mixed with 0.1% carbendazim and dexon.
④ Shade and insulation: In summer, after laying a layer of shade netting flat over the seedbed, set up a small arch shed and cover it with another layer of shade netting, using double-layer shading to retain moisture and cool the temperature for seedling cultivation. In winter and spring, use one layer of plastic film and one layer of shed film for double-film covering to keep warm during seedling cultivation.
5. Nutrient solution seedling cultivation: Nutrient solution seedling cultivation is currently a relatively good seedling method. It has the characteristics of low cost, convenient management, a high seedling survival rate and the ability to supply seedlings centrally, and it is welcomed by production and processing enterprises.
① Substrate: 25% vermiculite, 65% peat, 10% perlite.
② Substrate composting and disinfection: After thoroughly and evenly mixing all raw materials, evenly spray 50-100 fold formalin (40% formaldehyde) onto the substrate, then cover it tightly with plastic film. After 4-5 days of sealing, remove the film for ventilation and turn the nutrient soil so the formaldehyde volatilizes. It can be used after 2 weeks. The pH of the substrate also needs to be adjusted to 6.5-7; if too acidic, adjust with lime, and if too alkaline, neutralize with dilute hydrochloric acid.
③ Sowing: Fill the plug trays with substrate, water thoroughly, then use a special hole-punching machine to make the sowing holes. Use a seeder to sow the seeds into the holes, then cover with substrate.
How to Raise Broccoli Seedlings? Broccoli Seedling Cultivation Techniques
Broccoli is a very popular vegetable. In the broccoli cultivation process, doing a good job of seedling cultivation is the foundation of broccoli planting and is directly related to the yield and quality of broccoli. So how do you raise broccoli seedlings? Below is an introduction to broccoli seedling cultivation techniques.
Environmental Requirements for Broccoli Seedling Growth and Development
Broccoli seedling growth and development includes three stages: the germination stage, the basic vegetative growth stage and the rapid seedling growth stage. Broccoli prefers cool conditions and is a semi-cold-tolerant vegetable. The minimum germination temperature is 3°C, the optimum is 20-25°C, and the maximum is 35°C. The optimum plant growth temperature is 20-22°C, and the head will suffer freezing damage at low temperatures of -5-3°C. Flower bud differentiation does not have strict low-temperature requirements; for early-maturing varieties, flower bud differentiation can be completed as long as the average temperature is below 20°C. However, encountering low temperatures during the seedling stage will cause small heads to form, losing marketability and reducing yield. Growth is slow when the temperature is below 8°C.
Medium and late-maturing varieties require lower temperatures for flower bud differentiation, so they cannot be cultivated in the high-temperature season; otherwise they will form leafy heads, hairy heads and scorched buds. Therefore, broccoli has relatively strict sowing date requirements. Broccoli requires ample light, but is not strict about day length. It prefers moisture, but is not drought-tolerant or waterlogging-tolerant, and has relatively strict water requirements, especially during the seedling stage, when drought prevention and waterlogging prevention are the focus of management. The seedbed soil is required to be loose, fertile, and good at retaining and draining water.
Broccoli Seedling Cultivation Methods
Broccoli seedling cultivation methods are related to variety characteristics and crop rotation arrangements. The eastern coastal area of Zhejiang Province generally uses open-field sowing plus shade netting to cool the temperature plus agricultural film covering to prevent rain.
Standards for Strong Broccoli Seedlings
Seedling age 30-35d, leaf age 5-6 true leaves, robust growth, free of pests and diseases, thick stems, relatively short internodes, relatively large and thick leaves, normal leaf color, well-developed root system, abundant fibrous roots, and uniform plant growth.
Broccoli Seedbed Preparation
1. Seedbed selection: For broccoli seedling cultivation, choose a field with high and dry terrain, good drainage, ventilation and light transmission, and loose soil rich in organic matter, and where cruciferous vegetables have not been planted in the past two years, as the seedbed. For seedling cultivation, reserve enough seedbed at a ratio of 1:20. Plow the soil 1 week before sowing, and apply 25 kg of high-efficiency compound fertilizer per 667 sq m, deeply applied throughout the layer. The seedbed bed is 2 m wide including the ditch, the ditch is 40-50 cm wide and 15-20 cm high, with deep ditches and high beds. Seedbed preparation requires the lower layer to be coarse and the upper layer loose, and the bed surface to be fine, level and smooth.
2. Seedbed disinfection: For export broccoli seedling cultivation, the national pollution-free vegetable production operating regulations must be strictly implemented. For seedbed disinfection, use 25% Ridomil 500-fold solution plus 40.7% Lorsban 800-**** fold solution to spray the seedbed before sowing for disinfection and sterilization and to kill underground pests.
3. Chemical weed control before sowing: To reduce weed damage during seedling cultivation and at the same time lower the cost of seedling production, choose the dryland herbicide Dual, which has good safety and a broad weed-killing spectrum. The dosage is 20 mL of 70% Dual emulsifiable concentrate added to 15 kg of water, sprayed on the bed surface before sowing, and water the seedbed thoroughly.
4. Pre-sowing soil moisture regulation: While completing the above tasks for broccoli seedling cultivation, the seedbed soil moisture must be adjusted properly. Too little soil moisture affects seed imbibition and sprouting; too high humidity causes soil air blockage and seed rot. Therefore, the principle of pre-sowing moisture regulation for broccoli is that the bed surface is thoroughly wet and the bed ditch seeps water. This can not only reduce the porosity between soil particles and prevent broccoli seeds from sinking too deep and affecting emergence, but practice has also proved that the degree of soil dryness and wetness is directly related to the quality of emergence.
Sowing Broccoli
1. Determine a reasonable sowing period: The main basis for determining the sowing period is variety characteristics, weather conditions and cultivation purpose. In the eastern coastal area of Zhejiang, the sowing period for extra-early-maturing varieties such as Lüfeng and Qingfeng is mid-July to mid-August; for early-maturing varieties such as Youxiu it is early to mid-August; for medium-maturing varieties such as Lüdai and Malasong it is late August to early September; and for late-maturing varieties such as Meilü 90 and Fuxing it is mid-September to early October.
2. Determine a reasonable sowing rate: Broccoli seeds are small. In order to ensure the number of seedlings used in the field and give the seedlings sufficient growing space, the field seed rate must be calculated scientifically. The calculation formula is: seed rate (g/667 sq m) = [number of seedlings/667 sq m x (1 + safety factor)] x 1000-grain weight of seeds / germination rate. The germination rate of qualified seeds is above 85%, and the safety factor for raising seedlings is 80%. At present, the 1000-grain weight of main varieties is 3.17 g for Youxiu, 3.6 g for Lüdai, 5.56 g for Meilü 90, 2.96 g for Chaoli, and 3.94 g for Fuxing. Calculated accordingly, the seed rate for 667 sq m of field is 12 g for Youxiu, 15 g for Lüdai, 20 g for Meilü 90, 12 g for Chaoli, and 15 g for Fuxing.
3. Sowing: Sowing must be uniform. For seedling cultivation, the method of mixing seeds with fine mud and sand and direct sowing of dry seeds is often used, sowing broccoli seeds evenly on the prepared seedbed. The sowing time should preferably be on a clear evening or a cloudy day. Generally, after sowing broccoli seeds, fine soil is not used to cover the seeds; instead, after sowing, water is sprayed with a fine nozzle so that the seeds and bed surface are in close contact, and then 2-3 layers of shade netting are covered on the bed surface to shade, cool and retain moisture.
Broccoli Seedbed Management
1. Seedbed management: Among broccoli seedling cultivation techniques, seedbed management is the most important. During the germination and emergence period, broccoli needs 2-3 days and nights from sowing to emergence. The time is short, but management requirements are high. The focus should be on strengthening observation, proceeding from the overall environmental conditions of the seedling stage, and paying attention to regulating the two main factors of temperature and moisture.
Throughout the germination period, field observations must be made 3 times a day: in the morning, in the early afternoon and in the evening, observing seed sprouting, the dryness and wetness of the bed surface soil, the intensity of sunlight, or field drainage conditions on rainy days. Under clear and high-temperature conditions from July to September, during the germination and emergence period, watering is mainly relied upon to regulate soil temperature, keeping the soil temperature at the suitable level of 25-30°C to facilitate normal emergence. Watering can be done before noon and in the evening, and try to avoid rainy weather after watering. During this period, cover the bed surface with 2-3 days and nights of shade netting to cool the temperature and prevent rain. After emergence, when the two cotyledons unfold and turn green, remove the shade netting in time.
2. Management during the basic vegetative stage of seedlings: From cotyledon greening to the 2-leaf 1-heart stage is the basic vegetative stage of broccoli seedlings. After the cotyledons unfold and turn green, broccoli seedlings enter an independent autotrophic stage. During this period, if root growth and absorption are poor, or if the temperature in the seedbed is too high, the seedlings are prone to poor growth and development. With the growth and unfolding of true leaves and the expansion of leaf area, the role of the cotyledons gradually disappears after the 2-leaf 1-heart stage. Management during this period is the key to cultivating strong seedlings. Management mainly focuses on the following aspects. First, set up the small arch shed in time and cover it with shade netting. Cover with shade netting from 8 a.m. to 4 p.m. on clear days to cool the temperature, and remove the shade netting at other times. Do not cover with netting on cloudy days and light rain days. The intermittent net covering lasts for 1 week.
Second, strengthen water management. After rain, clear the ditches and drain in time to ensure no water accumulates in the field; after the soil surface dries on clear days, water in time to preserve moisture. Third, prevent typhoons and heavy rain. Pay close attention to forecasts of severe weather such as typhoons and heavy rain, and take various disaster prevention measures before typhoons and heavy rain arrive. Agricultural film can be covered on the small arch shed, and every 2 m along the bed edge another arch rod can be used to roll up the agricultural film to form a ventilation opening for ventilation and dehumidification. Between every two arch rods, use a stake to press down the film. Cover the top of the agricultural film with shade netting and use nylon rope or film-pressing wire to pull it tight and fix it to the stakes.
After typhoons and heavy rain, remove the agricultural film, shade netting and other facilities in time to prevent seedling spindling. Fourth, strengthen the prevention of pests and diseases. From emergence to the 1-leaf 1-heart stage, promptly use 40.7% Lorsban 800-fold solution plus 3% Jinggangmycin 500-fold solution to prevent damage by the striped flea beetle and to prevent damping-off and seedling blight. At the 2-leaf 1-heart stage, use 75% chlorothalonil 1000-fold solution plus 3% Jinggangmycin 500-fold solution to prevent damping-off and seedling blight.
Management during the rapid seedling growth stage: After the 2-leaf 1-heart stage, seedlings enter the rapid growth stage, during which 90% of seedling growth is formed. At this time the temperature is still relatively high, and roots form and grow very quickly. In order to cultivate strong seedlings, management during this period should focus on control.
Management mainly focuses on the following aspects: First, continue to do a good job of preventing typhoons and heavy rain, referring to the methods used during the basic vegetative growth stage of seedlings.
Second, continue to do a good job of water management based on dry and wet conditions, preferring dry over wet.
Third, do a good job of thinning at the 2-leaf 1-heart stage so that the growing space for seedlings in the seedbed reaches a uniform level of one plant per 10 square centimeters, ensuring 50,000 seedlings per 667 sq m.
Fourth, control fertilization throughout the seedling growth period, but apply a small amount of urea to weak and small seedlings to promote balance. Fifth, strengthen pest control. During the pest occurrence period, use 5% Regent 1500-fold solution to control diamondback moth, imported cabbageworm and cabbage webworm; use 20% Mimic 1000-fold solution plus 10% beta-cypermethrin 1500-fold solution to control beet armyworm and tobacco cutworm; use 10% imidacloprid 3000-fold solution to control aphids.
The above is the complete guide to broccoli seedling cultivation techniques. Friends who grow broccoli can refer to the above methods and combine them with actual growing conditions to carry out scientific seedling cultivation.
How to Raise Broccoli Seedlings? Broccoli Seedling Cultivation Techniques
Broccoli is one of the more commonly grown vegetables in recent years and has relatively high economic value. In the broccoli cultivation process, in order to ensure the yield and benefits of broccoli planting, doing a good job of broccoli seedling cultivation is the foundation. So how do you raise broccoli seedlings? The broccoli seedling cultivation techniques are introduced below.
Image: Broccoli
I. Variety Selection
Broccoli is a vegetable that prefers cool conditions. Choose varieties with strong plant growth vigor, dark green heads, few scorched heads, arc-shaped round heads, few side shoots, small buds, large heads, disease resistance, heat tolerance, cold tolerance and wide adaptability, such as Japan's Youxiu, Longlü and Shanshui. Other varieties such as Yuguan, Dongfang Lübao, Wanlü and Lüxiu, or various high-quality varieties selected according to market demand, may also be used, but they must meet the national second-grade seed standard before use.
II. Sowing Time
For autumn double-cover cultivation, sow in early July; for overwintering cultivation in solar greenhouses, sow from late July to August; for early spring cultivation in solar greenhouses, sow from early September to early October; for early spring cultivation in plastic tunnels and small arch sheds, sow in November; for spring plastic film cultivation, sow in January.
Image: Broccoli
III. Seed Treatment
1. Seed soaking:Soak the seeds in warm water at 33°C for 15 minutes, stirring constantly. Stop when the water temperature drops to 20°C, then continue soaking in warm water for 4 hours. Rinse clean with clear water and then germinate.
2. Germination:Wrap the soaked seeds in moist cotton gauze and germinate them at 30°C. Rinse once a day with clear water, and sow when 60% of the seeds have sprouted white.
Image: Broccoli
IV. Open-Field Seedling Cultivation
1. Seedbed selection:The broccoli seedling stage is relatively short. Choose a seedbed on a field with high terrain, convenient drainage and irrigation, soil rich in organic matter, and where cruciferous vegetables have not been grown in the past two years or where the previous crop was rice. The seedbed should preferably run north-south.
2. Apply sufficient basal fertilizer:Deep plow 15-20 days before sowing. Apply 15 kg of NPK compound fertilizer plus 5 kg of superphosphate per mu 7-10 days before sowing, or sprinkle 2500 kg of decomposed human manure, to ensure an adequate nutrient supply during the seedling stage. Turn and rake the soil finely and make a sowing bed about 1.2 m wide. The seedling field ratio is 1:20-30.
3. Mix with chemicals and sow:Before sowing, water the seedbed thoroughly once, and apply 1000-fold phoxim or similar chemicals to prevent underground pests. When sowing, mix the treated seeds evenly with an appropriate amount of sand and broadcast them uniformly in the seedbed. After sowing, press with an iron shovel, then spread a layer of medicinal soil mixed with 0.1% carbendazim and dexon.
4. Shade and insulation:In summer, after laying a layer of shade netting flat over the seedbed, set up a small arch shed and cover it with another layer of shade netting, using double-layer shading to retain moisture and cool the temperature for seedling cultivation. In winter and spring, use one layer of plastic film and one layer of shed film for double-film covering to keep warm during seedling cultivation.
Image: Broccoli
V. Nutrient Solution Seedling Cultivation
Nutrient solution seedling cultivation is currently a relatively good seedling method. It has the characteristics of low cost, convenient management, a high seedling survival rate and the ability to supply seedlings centrally, and it is welcomed by production and processing enterprises.
1. Substrate:25% vermiculite, 65% peat, 10% perlite.
2. Substrate composting and disinfection:After thoroughly and evenly mixing all raw materials, evenly spray 50-100 fold formalin (40% formaldehyde) onto the substrate, then cover it tightly with plastic film. After 4-5 days of sealing, remove the film for ventilation and turn the nutrient soil so the formaldehyde volatilizes. It can be used after 2 weeks. The pH of the substrate also needs to be adjusted to 6.5-7; if too acidic, adjust with lime, and if too alkaline, neutralize with dilute hydrochloric acid.
Image: Broccoli
3. Sowing:Fill the plug trays with substrate, water thoroughly, then use a special hole-punching machine to make the sowing holes. Use a seeder to sow the seeds into the holes, then cover with substrate.
[Editor's Conclusion]Broccoli is a cold-tolerant vegetable, and mastering its germination temperature is key during seedling cultivation. The above has introduced broccoli seedling cultivation techniques for everyone, and we hope it can help you!