Production Technology of Lily (Lilium)

Introduction of Lily (Lilium)

The lily (Lilium) is one of the important members of the family Liliaceae. Lilies are among the top 10 flowers of the world traded for high-value flowers with attractive colors, excellent vase life, and in some cases with exhilarating fragrance. Lilies are native to the Northern Hemisphere. They are widely used in the floral industry as cut flowers and potted plants. The Lilium are classified into three important groups like Asiatic hybrids, LA, and Oriental hybrids marketed nearly year-round as highly remunerative cut flowers. Quality flowers and bulbs can be produced both in hills. and Northern plains conditions, however, quality bulb production is possible in hills.

Climate and soil Requirement for Lily (Lilium)

Climate Requirement for Lily Cultivation

Lilium needs partial shade (40-50% ) during the growing season and can be grown successfully under protected conditions. In the areas that experience cool climates during the growing period, quality flowers can be grown under shade net house/polyhouse conditions. The climatic conditions of the low, mid, and high hilly areas are suitable for growing lilies to supply the flowers round the year in the market. In the plains favorable climatic conditions prevail only during the winter season, to produce quality flowers.

Lilies need 2,000-3,000 foot candles of light for quality flower production. In low light conditions such as photoperiod, less than 12 to 14 hr an 8 hr night interruption prevents the bud drop. A good rooting system is important for obtaining a higher yield of good-quality flowers and bulbs. The optimum day and night temperature for obtaining higher yield and quality of Lilium is 20-25°C and 8-12°C during day and night, respectively. Optimum humidity inside the greenhouse must be around 60-70%.

Soil Requirement for Llily Cultivation

Lilium can be grown in a wide range of soils, provided the structure and drainage of the soil are good. However, the best flowers are produced when plants are grown in sandy loam soil.

Heavy clay soil, with poor drainage, restricts the growth of plants and bulbs due to poor root development and promotes disease incidence due to excessive soil moisture. However, heavy soils can be made cultivable by mixing a thick layer of sand along with well-rotten manure. To improve the structure of the soil, decomposed farmyard manure (FYM) @ 5-8 kg/ m² is incorporated in the soil. Soil having a pH range between 5.5 and 6.5 is suitable for cultivation. Lilium needs weed-free well prepared sandy soil for both flower and bulb production. Soil sterilization should be done with 2% formaldehyde or methane sodium @25/ acre at least one month prior to bulb planting. About 30 40 cm deep soil is dug out from the beds and the bottom soil is drenched with formaldehyde solution quickly and the trench is filled and leveled with the removed soil. The bed is then quickly covered with polyethylene sheets for at least 15 days, after the sterilization process the polyethylene sheets are removed and the soil is dug again and irrigated thoroughly before planting.

Varieties of Lily (Lillium)

The selection of cultivars for cut flower production depends upon various factors such as suitability of the variety for selected site, plant height, size of flowers, preferred color choice by markets, the purpose of growing, and availability of bulbs. Mainly yellow, pure white, and pink colors are preferred and have good demand in the markets compared to other colors. Some of the important varieties of Asiatic hybrid lily, LA lily, and Oriental hybrid lily.

Asiatic hybrid lily

• Characteristics – The Asiatic hybrid Lilies are derived from seven Asian species. These hybrids have the characteristics of early flowering (10-12 weeks), upright flower, ease to propagate, and resistance to insects and diseases.
• Cultivars – Connecticut King, Enchantment, Grand Paradiso, Jollanda, Monte Rosa, Pollyanna, Salmon Beauty, Snow Star, Red Tiger. Roma, London, Alaska, Pareto. Novana. Sancerre, Brunallio. Elite. Apeldoon, Dreamland. Mona, Nove Cento, etc.

L A lily

• Characteristics – Cultivars of Lilium longiflorum have been crossed with Asiatic hybrid lilies to develop the LA hybrids. These hybrids have the characteristics like Asiatic hybrid lilies but are dwarf and sturdy.
• Cultivars – Brindisi. Ercocana. Pavia, Casa Rosa, Evening Star, Royal Dream, Royal Victory, Salmon Queen, Centurion, etc.

Oriental hybrid lily 

• Characteristics – The Oriental hybrid lilies are derived from different species. They are late flowering (14-16 weeks) and produce fragrant flowers.
• Cultivars – Casa Blanca, Mona Lisa, Everest, Stargazer Pink, Stargazer White, Sans Souci, Primeur, Larwe, Journeys End, Acapulco, Tiber, White Mountain, Dame Blanche, Marco Polo, etc.

Propagation of Lily 

Lilies are commonly propagated by vegetative means through bulbs, scales, bullets, and bulbils. Micropropagation has also been a successful method for large-scale multiplication. Propagation through seed is used by the breeders for evolving new varieties.

By Seed

Seeds may be sown indoor in flat pots during winter and planted outdoor in the spring. Good soil mixture for seed sowing consists of 7 parts loam, 3 parts peat, and 2 parts sand. Seeds are sown in pots and covered with finely screened leaf mold. The compost should not be allowed to dry out or be kept too wet and seeds should be sown in rows to facilitate transplanting. 

By Bulblets

Bulblets vary in size from 0.5-1.5 cm and are collected while digging up the mother bulb after leaves senesce. Lilies are commonly multiplied by bulblets formed on the stems of most lilies just below the ground level but above the mother bulbs. Bulblets required storage in moist cocopeat at 4°C for 8 to 10 weeks for breaking the dormancy. After the dormancy is overcome bulblets are planted in open field conditions for size enlargement. It usually takes 2-3 years to develop commercial-size bulbs.

By Bulbils

Bulbils are produced in the axils of the leaves. These are gathered and planted in the beds, frames, or flats and protected over winter. It usually takes 2-3 years to develop bulbs that are capable of producing good heads of bloom. Tiger and LA lilies are more capable of producing bulbils in hills and plains.

By Scales

Propagation through scales is a rapid means of multiplication. The bulbs should be lifted in early autumn and scales are removed carefully from the outer whorl of the bulbs. They are treated with systemic fungicides and are planted in well-prepared sandy soil beds. Shallow planting of scales is done at a density of 400-600 scales/m². Protective winter mulch is necessary after planting. Small bulblets 1 to 5/scale soon appears at the base of the scales in about six weeks’ time. Drying of leaves is an indication for harvesting the bulblets.

Cultivation of Lily 

Selection of bulb

The flower quality of the crop depends mainly upon the size of the planted bulb. A large size bulb produces taller and stronger plants with more uniform and heavier flowers as compared to a smaller-sized bulb. In Asiatic hybrid and LA lily size bulb circumference ranges from 12 to 18 cm but in the case of Oriental hybrid lily circumference of bulb varies from 14 to 22 cm.

Dormancy of bulb

Bulbs, do not sprout if sown immediately after harvest even under favorable growing conditions for a minimum of 45-60 days due to the dormancy or rest period of the bulbs. The dormancy period varies from cultivar to cultivar and between bulbs and bulblets. The dormancy can be broken by storing the bulbs in cold storage. Asiatic hybrid, LA, and Oriental hybrid lilies require cold treatment for a minimum period of 10 to14 weeks at 2 to 4°C before planting for rapid shoot emergence and flowering. When frozen bulbs are received from a planting material supplier, defrost the bulbs slowly at 7 to 13°C for 1 to 3 days.

Planting time and method for Lily Cultivation

In the north Indian plains, Lilium is planted during winter in the month of November-December. In the hilly regions, it is generally planted from November onwards. Planting time may vary from place to place as per the climatic conditions and altitude of the place. Method of Lilium planting depends upon the location, soil and climatic conditions and irrigation system to be employed. Depending upon the conditions, it can be planted in flatbeds, raised beds, and ridges. In light soils such as sandy and sandy loams, it is advisable to plant them in ridges or 1m wide raised beds. In the hilly regions having high rainfall during the crop, season planting should be done in raised beds and ridges to facilitate excess water to drain and hold the plant intact in the field.

Planting density for Lily

Planting of Lilium bulbs is done for two purposes, e.g., cut flower and bulb production. An appropriate number of bulbs need to be planted per unit area as per their size to get a crop of good quality. Above 14-16 cm circumference of Lilium bulb should be planted at a spacing of 15 cm x 15 cm row to row and bulb to bulb. Accordingly, 40-50 bulbs are planted per square meter net cultivated area.

Depth of planting for Lily

The depth of planting of bulbs in soil mainly depends on the size of the bulb, type of soil, and time of planting. Considering these factors and the purpose of planting bulbs and bulblets can be planted at 4-12 cm depth. Bulb planting should be done in such a way that a 4-10 cm soil layer covers its top.

Nutritional requirements for Lily

During the first three weeks of cultivation, Lilium does not require high nutrient levels. It is sensitive to the high salt content in soil and therefore, heavy fertilization has a retarding influence on root growth and flowering. Fertilizer requirement varies with the type of soil, fertilizer, and salt content of the soil and climatic conditions. The total quantity of sand, FYM, phosphorus, and potassium in the form of single super phosphate (SSP) and muriate of potash (MoP) respectively are incorporated into the soil before planting bulbs. After three weeks of planting of the lily bulb, calcium ammonium nitrate (CAN) @1 kg/100 m² should be applied. When the plants are in active vegetative growth, the second dose of CAN should be applied @ 1 kg/100 m². The Lilium is also easily damaged by fluorine-containing fertilizers such as superphosphate hence such fertilizers should not be used.

Irrigation Reuirement for Lily Cultivation

Drip irrigation system is suitable for Lilium. The water requirement of the Lilium plant varies with the soil texture, cultivar, development stage of the crop, salt level, and climate. Lilium bulbs require sufficient moisture in the soil before planting for quick and undisturbed rooting. Therefore, watering of the field should be done a few days prior to planting, in such a way, that the bulbs can be planted when the soil is moist but not excessively wet. If sufficient moisture is present at the time of planting little water is required till the emergence of plants. Watering is required more frequently in sandy soils and hot weather than in clay soil. The average water requirement is 8-10 1/m² during the dry period. The maximum acceptable level of chlorine in irrigation water used for greenhouse irrigation is 200 mg/liter.

Support/staking in Lily 

It is always necessary to support the lilies with wire or supporting net during their active growing period and it can be extended during the growing period parallel to the growth of plants till flower stems are harvested. It is advisable to place a few (3-4) layers of the net over the beds at the time of planting the bulbs and then slowly raise the net above the ground as the plants gain height.

Physiological disorders of Lily Flower

• Bud drop: Bud drop is characterized by withering and bleaching of the flower bud followed by necrosis. It generally occurs when the bud is 2-3 cm in length. It is associated with low light intensity and short photoperiod during which the stamens in the bud produce ethylene causing the buds to abort. Moisture stress and sudden change in temperature may also cause bud drop. Ensure proper temperature and humidity in the protected conditions to prevent bud drop.
• Leaf scorch: Leaf scorch occurs at the critical visible bud stage. First of all the young leaves curl slightly inward and then a few days later greenish-yellow to whitish spots appear on the scorched leaves. Leaf scorch occurs when there is a disturbance in the balance between the absorption and transpiration of water causing calcium deficiency in young leaves. In very severe cases, top scorching occurs where all leaves including the tender young buds will drop resulting in failure of the crop. Foliar application of 1.0% calcium chloride just before flower bud emergence reduces the leaf scorch.

Disease  and Pests in Lily

Diseases in Lily 

Insects attacking Lilium

 Aphids-suck sap from young plants, transmit viral diseases; thrips-feed on flowers and floral sheaths, cause silvering and whitish streaks; cut worms-feed on different parts of the plants and cut the plants at the base; and mites-feed on leaves under warm and shady locations, white specks appear on leaves which later turns to bronze color.

Harvesting and storage of Lily Flower

 Lilium flowers are generally harvested 15-20 cm above the ground level when they just start showing color and become loose. The remaining lower portion of the plants is allowed to grow so that development of the bulbs continues in the soil. The cut flowers should not be stored in the greenhouse for more than 30 minutes after harvest owing to high field temperature. Lilium is placed in a suitable preservative for pulsing (10% sucrose for 24 hr) and stored at 4-5°C for a short period to remove the field heat after harvest. If kept for a longer period, brown spots may develop on the surface of the petals in case of a sharp drop in temperature. After harvest flower stems are graded based on a number of flower buds/stem, length, and firmness of stem. The lilies are bunched in a bundle of six stems. The foliage must be removed from 10 cm of the lower portion of the stem so as to help in packing. After bunching the spikes of lilies are placed in a suitable holding solution containing a floral preservative or 200 ppm hydroxyquinoline citrate and 3% sucrose solution. Freshly cut Lilium which is pretreated with pulsing solution may be stored dry in tightly sealed moisture-retentive polythene foil at 2 to 5°C for 2-3 weeks.