How to Grow Lilies? Detailed Key Points for Cultivation in Solar Greenhouses in Northern China

Facility Conditions

Irrigation systems used in Northern China include drip irrigation, sprinkler irrigation and homemade sprinkler irrigation, among which the common ones are flood irrigation and homemade sprinkler irrigation. The advantages of flood irrigation and homemade sprinkler irrigation are that they are economical and practical. The disadvantage of flood irrigation is that the moisture is not easy to control, and it will increase the greenhouse temperature and destroy the soil structure; the disadvantage of homemade sprinkler irrigation is that the moisture is uneven. To produce high-quality cut flowers, it is best to use sprinkler irrigation and drip irrigation.

Heating System The heating methods mainly adopted in Northern China are: pipe heating and air heating. Pipe heating distributes heat evenly and the temperature is easy to control, but the investment cost is high. Air heating has a fast heating speed, but care should be taken to make its distribution even, and to ensure that the gas after combustion can be fully discharged.

Cooling System The cooling methods used in Northern China include micro-sprinkling, shade nets and ventilation.

Preparation Before Planting

Soil Soil structure is very important for the growth of lilies; soil rich in humus, with a deep, loose and well-drained layer, is suitable. Lilies prefer slightly acidic soil and are tolerant of salinity and alkalinity. The suitable soil pH for Oriental lilies should be between 5.5 and 6.5, and the most suitable soil pH for Asiatic lilies and Lilium longiflorum is 6.0 to 7.0.

In Northern China, the vast majority of the soil is loam and heavy loam, with a pH of 7.2 to 8.0. The soil permeability is insufficient, which affects growth; the pH value is on the high side, which affects the plant's normal absorption of the nutrients it needs, leading to various deficiency symptoms. Before planting lilies, organic fertilizer or peat should be used to improve the soil, and ferrous sulfate + citric acid should be used to adjust the soil pH value.

There are mainly two common methods of soil disinfection: steam disinfection and chemical disinfection.

Steam disinfection: rarely used in practice.

Chemical disinfection: further divided into soil disinfection and continuous-cropping soil disinfection. Conventional soil disinfection refers to soil being planted for the first time, and treatment with general fungicides + insecticides is sufficient; continuous-cropping soil disinfection refers to soil that has been planted continuously many times, and at this time the soil must be strictly disinfected. At present, chlorination disinfection is mainly used; its advantage is good effect, and its disadvantages are that it is complicated to use, requires professionals to complete, and is highly toxic with high residues. The alternative product is Basamid, which is simple to use, low in toxicity and low in residue.

Thawing and Disinfection of Bulbs Thaw the bulbs immediately after arrival, placing them in a cool place at 10°C to 15°C to thaw slowly. If planting cannot be carried out in time, do not freeze them again, otherwise frost damage is likely to occur. The bulbs should be placed at 0°C to 2°C, where they can be stored for two weeks. At 2°C to 5°C they can be stored for one week; the plastic film should be opened during storage.

After the bulbs have completely thawed, disinfect them. The main disinfection method is soaking in a disinfectant solution, mainly with carbendazim and dexon (in actual practice, if the bulbs show no abnormalities and can be planted in time, disinfection may also be omitted, or disinfection may be carried out with water after planting).

Planting Depth and Density

These vary according to variety, size and season; generally, planting is denser and shallower in spring and summer, and sparser and deeper in winter. The planting density of Oriental lilies is listed below (expressed as bulbs per square meter).

Size

Variety 12 to 14 cm 14 to 16 cm 16 to 18 cm

Oriental lily 30 to 35 25 to 30 20 to 25

When planting in summer, because the temperature is relatively high, in order to prevent stem rot, in Northern China planting is generally carried out after the sprouts are 2 to 3 cm, with the top of the bulb 4 to 5 cm from the soil surface; for winter and spring planting, the top of the bulb is generally 6 to 8 cm from the soil surface.

Greenhouse Management After Planting

Temperature To obtain high-quality lily cut flowers, temperature control inside the greenhouse is very important. During the rooting period (the first three weeks after planting), the ideal temperature should be controlled between 12°C and 13°C, which is beneficial to the growth of lily stem roots; above 15°C is not beneficial to the development of stem roots. When the stem roots begin to grow, the new stem roots will soon replace the basal plate roots, providing 90% of the plant's water and nutrients, so to obtain high-quality lilies, the development of the stem roots is crucial.

If conditions permit, rooting can be carried out in a cold storage or cellar during the hot season, but with this method attention should be paid to controlling the moisture content of the substrate, which must not be too high.

After the rooting period is completed, gradually raise the temperature from 15°C to 17°C up to 15°C, with a maximum of 28°C; below 15°C it is easy to cause bud drop and yellow leaves.

Humidity It is suitable to keep the air humidity between 80% and 85%, but at the same time excessive fluctuation should be avoided, otherwise it will inhibit crop growth and cause leaf scorch in some sensitive varieties. The humidity inside the greenhouse is relatively high at night; when ventilating in the morning, the humidity should be reduced in stages and slowly, especially when the outdoor relative humidity is low, such as in very cold or very warm weather. In addition, on days when the relative humidity inside the greenhouse is low, large amounts of water should not be applied; in this case, it is best to water in the morning.

There is no specific standard for soil moisture; “forming a ball when held in the hand and falling apart when dropped” is sufficient. If conditions permit, before planting in the hot season, water once with cool water, which can not only lower the soil temperature but also benefit the development of stem roots. After planting, water thoroughly once immediately, and water a second time depending on the soil condition, generally no more than three days, after which irrigate according to the soil condition.

Fertilization

(1) For a greenhouse of half a mu, 6 to 8 cubic meters of decomposed organic fertilizer (cattle, sheep or pig manure) should be applied and mixed evenly with the soil; it is best to complete this about 15 days before planting;

(2) At planting time, an appropriate amount of long-acting chemical fertilizer can be applied as base fertilizer, and at the same time an appropriate amount of long-acting chemical fertilizer should be applied as base fertilizer, and at the same time an appropriate amount of insecticide and fungicide should be applied. Generally, for a greenhouse of half a mu, apply the stated kilograms of diammonium phosphate and 10 kg of potassium sulfate compound fertilizer; if conditions permit, about 20 kg of bone meal can also be added. For insecticides, carbofuran or aldicarb can be used; for fungicides, soil fungicide or dexon can be used;

(3) During the growth process of Oriental lilies, it is best to use calcium nitrate, potassium nitrate, diammonium and urea alternately;

(4) During the growth process, according to the growth situation, appropriately apply some foliar fertilizer or plant growth regulators.