A Detailed Guide to Cultivation Techniques and Seed Selection Methods for Planting Vegetables in Autumn and Winter

Autumn-winter and overwintering crops are the main crop cycles for many vegetable planting bases, and they are also the most difficult crop cycles to manage. Therefore, vegetables in this cycle especially require the selection of high-quality seedlings. To improve the seedling level of growers, the following introduces how to select seeds, precautions when purchasing seeds, and cultivation techniques for the benefit of fellow vegetable growers.

01. What are the characteristics of high-quality seedlings?

1. Excellent variety

Suitable for the local facility conditions (heat preservation capacity, lighting capacity, etc.), soil (soil type, soil fertility, pH value, salinity, etc.), climate (rain and snow weather, wind force, temperature), etc.

2. Good stress resistance

Adverse conditions include: extreme low-temperature weather, long periods of continuous rain, low-light weather, soil salinization, and other various factors unsuitable for vegetable growth.

3. Healthy and robust

Excellent seedlings require thick stems, complete cotyledons, deep green leaf color, and robust growth; the root system should be tender white and dense, with thick root hairs, and the roots should tightly wrap the substrate to form a complete soil plug that does not break apart; no yellow leaves, no pests or diseases, and the entire tray of seedlings should be neat and uniform.

02. How to select high-quality seedlings and avoid being cheated?

1. Reserve seedlings in advance

Many growers prefer to buy seedlings only when they are ready to plant, and often cannot buy strong seedlings of the right age.

2. Buy seedlings through proper channels

Some unscrupulous manufacturers, in order to reduce costs, use seeds, scions, rootstocks, etc. as inferior substitutes or even use counterfeit and shoddy products. Some manufacturers also transfer seedlings from other places without regard to whether the variety is adapted, and even sell seedlings directly to growers without quarantine.

3. Carefully sign a contract

Keep receipts well so that there is evidence to check when problems arise. Choose seedling companies with strong strength and good reputation. Good seedling companies have excellent germplasm resources, advanced seedling facilities and equipment, mature seedling technology, and good reputation, so they can guarantee seedling quality to the greatest extent.

03. Some precautions before cultivation

1. Reasonably arrange planting crop cycles

For open-field vegetables, attention should be paid both to avoiding meteorological disasters and periods of high pest and disease incidence, and to preventing overly concentrated sowing periods, which affect the reasonable arrangement of labor and cause concentrated harvesting and oversupply.

For facility vegetables, attention should be paid to reasonably arranging late-autumn delayed cultivation and autumn-winter and winter-spring production and their variety structures according to the vegetable price change patterns of the target market, local winter and spring climate characteristics, and the structural performance of different greenhouses.

2. Promote intensive seedling raising

The early stage of autumn-winter vegetable production coincides with the turn of summer and autumn, when meteorological disasters and pests and diseases occur frequently and at high rates. Using protective facilities for intensive seedling raising can effectively resist disasters and reduce damage, save seeds, save labor and costs, and ensure planting quality.

04. In cultivation management, you need to pay attention to these points

1. Light management

Actively take measures to increase light inside the facility. Keep the film surface clean, pay attention to lowering vines in time and removing diseased leaves and old leaves, increase ventilation and light transmission, and if conditions permit, artificial supplemental lighting can also be used.

2. Temperature management

In late autumn and early winter, the climate is not too cold. Facility vegetables should be protected from high-temperature heat damage during the day and from excessive temperature at night that causes spindly growth. In winter, the time for uncovering and covering the heat preservation coverings of solar greenhouses should be strictly controlled. After rolling up the heat preservation coverings in the morning, the suitable time is when the indoor temperature does not drop significantly; in the afternoon, when the indoor temperature drops to 20°C, the suitable time is to lower the heat preservation coverings, minimizing heat loss at night.

3. Fertilizer and water management

Before the Autumn Equinox, water in time and apply appropriate topdressing to promote early and rapid seedling growth. From the Autumn Equinox to Cold Dew, increase fertilizer and water supply to promote high quality and high yield. After Cold Dew, stop fertilizing and appropriately control watering, but late-autumn delayed facility cultivation and autumn-winter and winter-spring fruit vegetables are still growing vigorously, so sufficient fertilizer and water supply must be ensured. After the beginning of winter, fertilizer and water should be strictly controlled. Especially during the period from Major Snow to Major Cold, insist on not watering unless there is drought, choose a sunny morning just after a cold wave to water lightly, the water temperature must not be lower than 10°C, and apply as little topdressing as possible. After the weather turns warm in spring, appropriately increase water and fertilizer supply.

4. Gas management

For facility vegetables with insufficient organic fertilizer application or soilless cultivation, carbon dioxide gas fertilizer should be added so that the carbon dioxide concentration inside the facility reaches a suitable level. In severe winter, facility cultivation has little ventilation, so large amounts of urea and ammonium nitrogen fertilizer should not be applied, to avoid nutrient deficiency and ammonia poisoning. At the same time, when the temperature is relatively high at noon, attention should be paid to ventilation and air exchange to remove harmful gases inside the protected area.

5. Plant adjustment

The planting density of facility fruit vegetables is generally significantly greater than that of open-field cultivation, so plant adjustment must be strengthened to prevent shading due to overcrowding. In areas where continuous rainy, snowy, and hazy weather occurs frequently in winter, facility vegetables should be appropriately thinned of flowers and fruits and harvested early in a timely manner, to prevent premature aging of plants due to excessive burden.

05. Pest and disease prevention and control techniques

1. Agronomic prevention and control

Mainly includes comprehensive agronomic control measures adapted to local conditions, such as distant crop rotation, paddy-upland rotation, grafting and root replacement, age-appropriate strong seedlings, drip irrigation under film, coordinated promotion and control of water, fertilizer, air, and heat, and flushing application of microbial bacterial fertilizer, amino acid oligosaccharides, etc., to increase root activity and improve plant stress resistance.

2. Physical prevention and control

Use long-acting anti-drip and anti-fog functional films, rain shelters, shade nets, and insect-proof nets to cover and prevent pests and diseases. Use yellow and blue boards and frequency-vibration insect-killing lamps to trap and kill aphids, whiteflies, thrips, and lepidopteran pests. Use full ground coverage, high-temperature greenhouse sealing, space electric fields, and measures such as strengthening heat storage and insulation and ventilation and dehumidification to control low-temperature and high-humidity diseases. Actively demonstrate and promote biological food attractants. It is also possible to spray 26.9% quartz aqueous agent (Silicon Shark), forming a silicon dioxide crystal layer on the vegetable surface as a physical barrier to effectively prevent pathogen invasion and damage. For fields with severe grass damage, black, black-white double-sided, and silver-black double-sided plastic films should be used to cover and control weeds. Actively demonstrate and promote ozone biological waste treatment and ozone disinfection disease prevention technology and equipment.

3. Biological prevention and control

Demonstrate and promote measures such as Encarsia formosa for controlling greenhouse whiteflies and the use of sex attractants and biological pesticides to prevent and control pests and diseases according to local conditions.

4. Rational application of chemical prevention and control technology

This includes selecting high-efficiency, low-toxicity pesticides with short residual activity periods, high-atomization application equipment, and timely symptomatic medication. The use of high-toxicity pesticides with long residual activity periods is prohibited, and safety intervals must be strictly observed.

5. Soil disinfection and remediation technology

Use dazomet or lime nitrogen, etc. to treat the soil, cover with agricultural high-barrier film to control soil-borne diseases, and use microbial inoculants or biological bacterial fertilizer to repair the soil ecosystem. Increase the application of straw and straw-derived fertilizers, and use soil conditioners in combination to improve soil fertility.