Planting technique of asparagus in greenhouse

Hollow cabbage is one of the varieties of leafy vegetables that the general public likes to eat. It is produced more in summer and autumn, and it is not suitable for its growth in early winter and early spring, but in recent years, it has been successfully cultivated in small arch sheds, film greenhouses and other facilities. It can be listed and supplied before and after the Spring Festival, and better economic benefits have been obtained. let's take a look at the greenhouse planting technology of asparagus.

Variety selection of asparagus

There are two kinds of asparagus, namely seed propagation in the north, which is mainly selected by Thai sharp leaf varieties and can also be cultivated by local or Guangxi willow leaf varieties.

Sowing method of asparagus

1. Soaking seeds to promote germination: the seed coat of hollow cabbage seeds is thick and hard, and if sowed directly, it will germinate slowly because of low temperature, and it will cause seed rot in case of long-term low temperature, overcast and rainy weather, so it is appropriate to sow seeds after germination, soak seeds in warm water of about 30 ℃ for 18-20 hours, then wrap them in gauze and put them under 30 ℃ to accelerate germination, and sow seeds when 50% of 60% of the seeds are white.

2. Sowing method: hollow cabbage can be sown or strip sowed, the amount of seed used per mu is 15-20 kg, and after sowing, it is covered with fine soil about 1 cm thick. Strip sowing can dig a shallow trench 2-3 cm deep every 15 cm on the border surface, spread the seeds evenly in the shallow ditch, cover it with fine soil, and then cover the border with sunshade net, drench water, and uncover the sunshade net after emergence.

Planting of asparagus in greenhouse

1. Cultivation season: greenhouse cultivation can basically be produced and supplied every year. In order to obtain higher economic benefits, it should be sown from October to December and be listed from December to March of the following year.

2. Soil preparation and fertilization: hollow cabbage has fast growth rate, strong branching ability and needs more fertilizer and water. It is appropriate to apply sufficient basic fertilizer when planting. Generally, 1500-2000 kg of rotten organic fertilizer and 100kg of plant ash are applied per mu, which are fully mixed with the soil to form a border (bag ditch) of 20cm high and 130cm wide.

Greenhouse management of asparagus

1. Temperature and humidity management: when cultivated in greenhouse in winter, the temperature is low, the humidity is high, and the continuous low temperature, overcast and rainy weather lasts for a long time, which is extremely disadvantageous to the growth of temperature-loving asparagus, so heat preservation and cold prevention is the key to off-season cultivation. After sowing, when the sun is sufficient and the temperature is high, ventilation and humidity should be strengthened to avoid the temperature higher than 35 ℃ in the greenhouse to prevent plant diseases, so as to maintain exuberant growth and increase yield. If there is low temperature after sowing, the greenhouse should be sealed in time, and the temperature in the greenhouse should be kept above 10 ℃, otherwise it will cause freezing damage. The relative humidity of the air in the greenhouse may reach 100% in high temperature and rainy days. At this time, the thin films at or around the greenhouse must be opened in time for ventilation.

2. Fertilizer and water management: asparagus is a crop harvested many times, so in addition to applying sufficient base fertilizer, high yield can be obtained by topdressing many times. At the seedling stage, 10% of rare manure and urine can be applied with 1000-1500 kg per mu. When the seedlings have 3-4 true leaves, 15-20 kg of compound fertilizer and 2-4 kg of urea are mixed with 15-20 kg of compound fertilizer and 2-4 kg of urea. Asparagus needs a lot of water, so it should be watered frequently to keep the border moist.

3. Pest control: the main diseases of asparagus cultivated in greenhouse are seedling sudden disease and stem rot, which are caused by low temperature and high relative humidity. the occurrence of the disease can be reduced by reducing humidity. at the same time, it can be sprayed 700 times by Trichoderma or 800 times by carbendazim. The main pests are mites and red spiders, which can be controlled by 1000 times of propargite or 1500 times.

4. Timely harvest: generally, 35-45 days after sowing, when the plant grows to 35 cm high, it should be harvested in time.