Protected Cultivation Techniques of Carnation

• Carnation (Dianthus caryophyllus) is one of the top-ranking cut flowers worldwide.
• Popular for long vase life, wide color range, attractive forms, and pleasant fragrance.
• Requires cool climate with moderate temperatures, making protected structures essential in many regions.
• Mainly cultivated under polyhouses, greenhouses, or shade nets for high-quality cut flower production.

A. Importance of Protected Cultivation

• Ensures uniform quality flowers with long stems and large blooms.
• Protects from rain, wind, frost, and heat stress.
• Reduces disease incidence like Alternaria blight and Fusarium wilt.
• Enables year-round production, meeting both domestic and export market demand.
• Increases yield and vase life compared to open cultivation.

B. Suitable Protected Structures

• Naturally ventilated polyhouses – widely used for carnation in mid-hills.
• Greenhouses with controlled environment – for high-value export production.
• Shade nets (50%) – used for nursery and hardening of seedlings.

C. Site, planting and Soil Requirements

• A rich sandy loam soil is considered best for carnations.The planting time for carnation is September – October.
• Carnations are planted on raised beds up to20-30 cm height from ground. The top width of bed should be 100 cm and bottom width110 cm.
• The pathway Sterilization of beds may be done with Chloropicrin about 10-15 days before planting.
• Planting distance from plant to plant and from row to row is 15cm. with this planting distance the planting density is 20-30plants/m2.
• The flower yield is 300-400 flower/m2.
• Most promising varieties for standard types are Master, Tanga, Sonsara, Laurella, Solar,Dakar, Raggio di Sole, Cabaret and Bagatel,Cherry bag, Fantasia, Picaro, Ondelia,Sintonia, Macarena for spray types.

D. Varieties and Types

Based on Flower Form

• Standard carnations: Single large bloom per stem (e.g., White Sim, Red Corso, Yellow Solar).
• Spray carnations: Multiple smaller flowers per stem (e.g., White Liberty, Red Barbara, Orange Vogue).
• Miniature/pot carnations: Compact plants for potted culture.

Recommended Hybrids for Protected Cultivation

• Doris, Sunrise, White Liberty, Red Corso, Yellow Solar, Tanga, Master, Pink Sim.
• Locally, imported hybrids from Spain, Netherlands, and Israel are popular in Nepal.

E. Propagation and Nursery Raising

• Propagation method: Terminal stem cuttings (8–10 cm) from healthy mother plants.
• Rooting hormone (IBA 1000–2000 ppm) used to enhance rooting.
• Rooting media: Sterilized cocopeat, perlite, and vermiculite mix.
• Mist chambers or shade houses maintained at 80–90% RH for rooting.
• Seed propagation rarely used in commercial production.

F. Land Preparation and Planting

• Raised beds: 1–1.2 m width, 15–20 cm height.
• Incorporate well-decomposed FYM (20–25 t/ha) and sterilize soil.
• Drip irrigation system installed before planting.
• Spacing: 15 × 20 cm or 20 × 20 cm depending on cultivar.
• Planting time: Spring and autumn are ideal.

G. Fertilizer dose

• A nutritional dose of 40 g N, 20 g P2O5, and 10 g K2O is ideal.
• Liquid feeding of carnation plants with nutrient levels of190 ppm N and 156 ppm K, 1 ppm B with each irrigation water results in high grade carnation
• Ca deficiency- Weak stem with small flowers
• B deficiency- Calyx splitting and bud abortion

H. Training, Pinching, and Disbudding

• Training: Vertical support using nylon netting to maintain straight stems.
• Pinching:

Single pinching: At 6–8 pairs of leaves, encourages lateral shoots.

Double pinching: In high-density planting for uniform flowering.

• Disbudding: Removal of side buds in standard carnations to allow one large bloom per stem.

I. Irrigation Management

• Drip irrigation preferred for precise moisture.
• 2–3 irrigations per week depending on season.

• Avoid waterlogging to reduce Fusarium wilt.
• Maintain consistent soil moisture during bud development.

J. Environmental Management

• Temperature: Optimum 15–25°C. High temperature reduces flower size and color intensity.
• Light: Shading during summer; supplementary lighting during short winter days.
• Humidity: 60–70% ideal; high RH favors Botrytis.
• Ventilation: Proper side and top vents to regulate humidity and temperature.

K. Plant Growth Regulators (PGRs)

• GA₃ (25–50 ppm): Promotes stem elongation.
• CCC (500–1000 ppm): Used as growth retardant in spray carnations for compactness.
• BA/kinetin: Improves side shoot development.
• NAA/IBA: Promotes rooting in cuttings.

L. Major Pests

• Aphids – cause leaf curl and transmit viruses.
• Thrips – cause streaking of petals.
• Red spider mite – bronzing and webbing of leaves.
• Leaf miner – causes serpentine mines.

M. Major Diseases

• Fusarium wilt (Fusarium oxysporum f.sp. dianthi) – soil-borne, major constraint.
• Alternaria blight – leaf spots and stem lesions.
• Rust (Uromyces dianthi) – pustules on leaves.
• Botrytis blight – gray mold on flowers under high humidity.
• Viruses (Carnation mosaic, streak virus) – transmitted by aphids/thrips.

N. Harvesting

• First harvest: 5–6 months after planting.
• Harvest at tight bud stage for export; semi-open stage for local markets.
• Flowers cut with 50–70 cm long stems.
• Harvested early morning or late evening to maintain vase life.
• Postharvest: Keep flowers in water with preservatives (8-HQC, sucrose) and Store at 0–2°C, 90–95% RH for 2–3 weeks.

O. Yield

• Open field: 60–80 flowers/m²/year.
• Protected cultivation: 200–250 flowers/m²/year.
• Export quality flowers possible from greenhouse production.