Cultivation of Marigold

Botanical Information

• African Marigold: Tagetes erecta (2n = 24)
• French Marigold: Tagetes patula (2n = 48)
• Family: Asteraceae (Compositae)
• Plant Type: Hardy annual or short-lived perennial
• Flower Morphology: Composite flower head with ray and disc florets
• Pollination: Cross-pollinated by insects (entomophily), although self-pollination may occur in some varieties
• Root system: Well-branched fibrous root system

Importance and Characteristics

• Marigold is popular due to its easy cultivation, wide adaptability, attractive colors, varied shapes and sizes, and good keeping quality.
• Genetic male sterility is common in marigold.
• Potendry type of self-incompatibility is found in marigold.

Climate

• Requires mild climate for healthy growth and flowering.
• Planting is done in three seasons: Rainy, Summer, and Winter.
• Avoid planting African marigold between 1st week of February to 1st week of July, as it affects quality and yield.
• Staggered planting from 1st week of July to 1st week of February ensures a continuous supply of flowers from October to April.
• Maximum yield is obtained from September-planted crops.
• Optimum temperature for marigold cultivation: 18–30°C

Soil Requirements

• Grows in a wide range of soils except waterlogged areas.
• Best suited: Deep, fertile, well-drained sandy loam rich in organic matter.
• Soil pH: 6.0 to 7.5 (neither too acidic nor too alkaline).

Selection of Site

• Choose a sunny location for cultivation.
• Under shade, plants show excessive vegetative growth but fail to flower.

Varieties

• Arka Bangara-1
• Arka Bangara-2
• Arka Agni
• Pusa Narangi Gainda
• Pusa Basanti Gainda

Propagation

By Seed

• Common method of propagation.
• Seed rate: 1 to 1.5 kg/ha.
• Sow seeds on nursery beds in shallow furrows.
• Seedlings ready for transplanting in one month.

By Herbaceous Cuttings

• Used for non-seed-setting varieties like Giant African Yellow and Giant African Orange.
• Use apical shoots (10 cm) for cuttings.
• Each cutting should have 1–2 pairs of leaves.
• Inserted in sand medium (seed pan or nursery bed) for rooting.

Transplanting of Seedlings

• Use 1-month-old seedlings with 3–4 leaves.
• Water nursery beds a day before uprooting to minimize root damage.
• Transplant in the evening for better establishment.

Spacing

• African Marigold:
  60 × 30 cm or 45 × 30 cm
• French Marigold:
  20 × 20 cm or 20 × 15 cm

Intercropping & Companion Planting

• Acts as a trap crop in integrated pest management (IPM), especially for nematodes and whiteflies
• Commonly intercropped with:
  • Tomato
  • Cabbage
  • Chili
  • Brinjal
• Its strong aroma repels insect pests

Pinching

• Pinching = Removal of apical bud
• Encourages lateral branches and a bushy plant with more uniform flowers.
• Recommended after 40 days of transplanting for both African and French types.

Staking

• Required for tall African marigold varieties.
• Use bamboo sticks to support the plant.
• Prevents lodging and bent stems that affect flower quality.

Harvesting

• Harvest when flowers are fully open.
• Preferably harvest in the morning or evening.
• Irrigate the field before harvest to improve post-harvest flower quality.
• Regular flower picking and removal of dried flowers increase productivity.

Yield

• Varies with type and variety.
• Normal yield: 4–6 tonnes/acre
• Giant African Yellow (Sept. planting): up to 10 tonnes/acre

Seed Production: Seeds should be collected from winter crops only.

Seed Yield:

• African Marigold: 120–150 kg/acre
• French Marigold: 400–500 kg/acre

Insect-Pest Management

1. Aphids: Suck sap; controlled by spraying Neem oil or Imidacloprid
2. Thrips: Causes leaf curling and flower distortion
3. Nematodes: Marigold roots release chemicals (α-terthienyl) that suppress nematode larvae

Diseases

• Botrytis blight (Gray mold): Promoted by high humidity, treat with Captan or Carbendazim
• Powdery mildew: Appears in dry, warm weather; treat with Sulphur dust or Tridemorph
• Damping off (nursery stage): Prevent with proper drainage and fungicidal seed treatment