Detailed Explanation of Key Points for Early Spring Cucumber Planting and Cultivation Techniques
Early spring cucumbers are actually cucumbers that are seeded in winter and harvested in spring, generally grown in greenhouses, and have become one of the most important greenhouse products. With the promotion of greenhouse vegetables, we are no longer limited to eating certain vegetables in a certain season, but can eat them all year round. So how are early spring cucumbers grown?
Early Spring Cucumber Planting and Cultivation Techniques
1. Seed selection: Mainly use first-generation hybrid cucumber varieties suitable for local cultivation. Such varieties are required to be tolerant to low temperatures, have strong disease resistance, wide adaptability, be early-maturing, high-yielding, and high-quality.
2. Seedling raising: Select plump seeds, first soak them in warm water at about 40 degrees for half an hour, then use 10 ml each of 50% carbendazim and 50% thiophanate-methyl, add 2 kg of water, soak the seeds for 20 minutes, remove them and wash them clean with clear water; dry them and then sow. The seeding rate is 0.1 kg per mu, and the sowing time is from mid-to-late January to mid-February. Choose a plot that has not grown cucurbit crops in recent years as the seedbed, level the bed soil, water thoroughly, and sow after 24 hours. Sow 0.2 kg of seeds per square meter of bed surface, with a soil covering thickness of 2 cm. Keep the soil moist in the early stage, generally spraying a little water once a week, but it must not be too wet; control moisture during hardening in the later stage. When there are 2 to 3 true leaves, spray once quickly with 150 to 300 mg/kg ethephon to promote female flower differentiation and shorten internodes.
3. Land preparation: Choose a loose and fertile plot that has not grown cucurbit crops within 2 years and prepare the land finely. Apply 5000 kg of farmyard manure per mu; 100 kg of compound fertilizer, and 100 kg of cake fertilizer. About one week before transplanting, prepare the soil and make beds, with a bed width of 1 m, a ditch depth of 20 cm, and a width of 50 cm.
4. Field planting: Carry out in early to mid-March, choosing a sunny afternoon for planting. Plant 2 rows per bed, 2 plants per hole, with a hole spacing of 40 cm. Plant 4000 to 5000 plants per mu.
Seedling Stage Management
The management during the seedling raising period of spring cucumbers mainly includes temperature, humidity, and light regulation.
1. Temperature
The seedling raising period is in a low-temperature season, so temperature management should be carried out according to the temperature requirements of seedlings at different stages.
Temperature management during the seedling period should pay attention to two key periods. First, from sowing to 60%—70% emergence, about 28℃ is required; maintaining a relatively high temperature is helpful for promoting emergence and reducing the consumption of nutrients by the seeds themselves. Second, from full cotyledon expansion to true leaf appearance, a relatively low temperature should be maintained to control excessive elongation of the hypocotyl that causes spindly growth and to prevent damping-off disease. Attention should also be paid to hardening the seedlings in the later stage of seedling raising to improve the cold resistance of the seedlings and adapt them to the environmental conditions after planting.
In addition, attention should be paid to changes in the seedbed soil temperature, because the soil temperature during the seedling period is closely related to the germination and emergence of cucumber seeds and the growth and development of seedlings. The suitable soil temperature for cucumber seedlings is 25℃ during the day and 20℃ at night before emergence, and 22℃ during the day and 18℃ at night after emergence. During the seedling raising process, the soil temperature is affected by the air temperature. When the minimum air temperature in the seedbed is 10℃, the soil temperature at 10 cm can be maintained above 12—13℃. Therefore, to maintain the suitable soil temperature required for cucumber seedling raising, soil heating measures are also needed, such as electric heating wire warming, fermentation heating, and heated kang warming.
2. Light
Winter and spring seedling raising is in a season of short daylight and relatively weak light intensity, so fewer photosynthetic products are formed and weak seedlings are likely to appear. Therefore, light should be obtained as much as possible. Under the condition that the seedlings are not frozen, uncover the covering early and cover it late to increase the lighting time; keep the film clean to increase light transmittance; on cloudy days, the covering should also be uncovered under permissible conditions to see more scattered light; after snowy days, sweep away the snow and uncover the covering in time to let in light.
Field Management
1. Fertilizer and water management Cucumbers grow quickly, so fertilizer and water must be supplied in time. The fertilization method adopts the principles of “light fertilizer applied frequently” and “small amounts at many meals.” Generally, apply fertilizer once after every two harvests. Keep the soil moist throughout the growing period. After entering the peak fruiting period, according to the soil moisture content, water or irrigate once every 1 to 2 weeks.
2. Temperature control First close the greenhouse for about 7 days to promote seedling survival. Maintain the greenhouse temperature for a long time at 20 to 25 degrees during the day and 15 to 18 degrees at night. On sunny days, because the temperature rises, the greenhouse film should be uncovered for ventilation; on cloudy and rainy days, close the greenhouse to keep warm. By late April, when the temperature stabilizes above 15 degrees, the film can be removed. Strengthen ventilation to promote vigorous seedling growth. When the vine is 30 cm long, begin to set up supports and guide the vines.
3. Use of hormones When greenhouse cucumbers bloom, because the temperature is low and insects are less active, fruit-setting hormone or 920 should be sprayed on flowers to retain fruit, and artificial pollination can also be used to increase the early fruit-setting rate.
4. Pest and disease control The main ones include downy mildew, Fusarium wilt, and powdery mildew. Starting from the seedling stage, spray Bordeaux mixture once every 2 weeks; after applying chemicals to the roots; spray fungicide once every 7 to 10 days. Pests include aphids; high-efficiency and low-toxicity pesticides can be used for control.
Harvesting
Open-field spring cucumbers generally begin to be harvested about 25 to 30 days after planting, and the harvest period is about 40 to 60 days. The general yield per mu is 3500 to 4500 kg. Cucumbers should be harvested at the right time, when the top of the fruit changes from pointed to round. At this time, the fruit has fully grown but is not old, which is the suitable harvest period. If harvested too early, the yield is low; although tender, it has less juice and poor flavor. If harvested too late, the skin is thick and hard, the quality is poor, it is difficult to sell, and it weighs down the vine, hindering the growth of other cucumbers. When harvesting, both the growth of the cucumber and the growth and fruit setting of the whole plant should be considered.
When harvesting the root cucumber, because the vine is still small and the root system is still growing, and the root cucumber is located at a low node, if it is not picked in time, it will affect plant growth. Therefore, it should be harvested appropriately early, which not only allows earlier listing but also prevents the vine from being weighed down and prevents fruit abortion. If the plant is weak and cannot grow vigorously, the root cucumber can be thinned out while still young. If the plant grows vigorously, the cucumbers on the vine can be harvested appropriately later, so that there are always medium and small cucumbers on the vine, which can prevent excessive vegetative growth. In the peak fruiting period, stems and leaves grow vigorously, and the cucumbers can be harvested after fully growing, generally once every other day. In the late fruiting period, the plant has aged and deformed cucumbers are likely to appear. These cucumbers should be removed early so that nutrients are concentrated on supplying normal cucumbers. Harvesting should be done in the morning, when the quality is crisp and tender. During harvesting and boxing, cucumbers should be handled gently, and the fruit should retain its top flower and spines.
The above is the early spring cucumber planting method summarized for everyone by the editor. I hope it can help everyone. Although now no matter what vegetables or fruits are available all year round, seasonal fruits and vegetables taste better and are more nutritious, so in daily life it is still best to eat more seasonal vegetables and fruits!