Protected Cultivation Techniques of Gerbera

• Gerbera (Gerbera jamesonii) is a popular ornamental cut flower belonging to the family Asteraceae.
• It ranks among the top commercial flowers globally due to its bright colors, long vase life, and year-round demand.
• Protected cultivation ensures higher yield, quality blooms, and uniformity compared to open-field cultivation.
• Ideal for greenhouse, polyhouse, and net-house systems.

A. Importance of Protected Cultivation for Gerbera

• Ensures controlled growing conditions such as temperature, humidity, and light.
• Provides protection from heavy rainfall, high wind, and direct solar radiation.
• Reduces biotic stress caused by pests and diseases.
• Facilitates year-round production and export-quality flowers.
• Increases productivity (200–250 flowers/plant/year).

B. Climate and Environmental Requirements

• Temperature: Optimal day temperature 18–24°C; night temperature 12–14°C.
• Humidity: 70–75% relative humidity is ideal.
• Light: Requires 12–14 hours of light; shade nets (30–40%) may be used in summer.
• Ventilation: Natural or forced ventilation ensures optimum CO₂ concentration and air circulation.

C. Varieties

1. Varieties for green house: Julia, Natasha, Alcatraz, Havana, Faith, Dakota, Grizzly, Basic.
2. The high yielding varieties Sonata, Esmara, Opium, Solem, Gucci, Diana, Naome, Martinque, and Maidemoselli were useful for obtaining higher returns under naturally ventilated polyhouses

D. Propagation and Planting

• Propagated mainly through tissue culture plantlets or division of suckers.
• Plantlets are virus-indexed, healthy, and uniform in growth.
• Planting time: Best during February–March and September–October in Nepal.
• Spacing: 30 × 30 cm; about 8–10 plants per m².
• Bed preparation: Raised beds (1 m width, 20–30 cm height) with well-drained media.

E. Growing Media

• Well-drained, porous, and sterile growing media is essential.
• Common mixture: Cocopeat + Perlite + Vermicompost (3:1:1).
• pH: 5.5–6.5; EC: < 1.0 dS/m.
• Soil solarization or fumigation is essential before planting.

F. Nutrient and Irrigation Management

• Gerbera requires balanced nutrition under fertigation.
• Macronutrients: NPK in 3:1:4 ratio; Ca, Mg, S supplementation needed.
• Micronutrients: Fe, Zn, Mn, Cu, B applied through foliar sprays or fertigation.
• Irrigation: Drip irrigation preferred; 2–3 irrigations per week depending on season.
• Maintain optimum soil moisture (field capacity).

G. Crop Management Practices

• Mulching: Black polythene or organic mulch to reduce weed growth and conserve moisture.
• Disbudding: Removal of side buds to improve flower quality.
• De-leafing: Removal of diseased, damaged, or old leaves for better aeration.
• Staking: Not required in gerbera, but flowers must be harvested carefully to avoid bending.

Use of PGRs:

• GA₃ (50–100 ppm) promotes flower stalk elongation.
• CCC (Cycocel, 250 ppm) reduces excessive vegetative growth.

H. Pest and Disease Management

Major Pests:

• Aphids, whiteflies, thrips, leaf miners, mites.
• Control: Yellow/blue sticky traps, neem oil sprays, systemic insecticides.

Major Diseases:

• Powdery mildew, botrytis blight, fusarium wilt, root rot.
• Control: Proper ventilation, fungicide sprays, use of disease-free planting material.
• IPM practices: Use of biological control agents (Trichoderma, Pseudomonas, predatory mites).

I. Harvesting and Post-Harvest Management

• Harvest at half to two-thirds open stage when outer 2–3 whorls are perpendicular to the stalk.
• Harvesting method: Twist and pull the stem from the base to avoid rotting.
• Grading: Based on stalk length, flower diameter, and freshness.
• Vase life: 7–14 days with preservative solution (Sucrose + Germicide).
• Storage: 2–4°C for 2–3 weeks under 90% relative humidity.

J. Yield

• Average yield: 200–250 flowers/plant/year under greenhouse conditions.
• Commercial productivity: 150,000–200,000 flowers/ha/year.

K. Economic Importance

• High return on investment due to year-round demand.
• Export potential in European and Middle Eastern markets.
• Significant employment generation in floriculture industry.