Cultivation of Costus (Saussurea costus)

Botanical Information

• Latin Name: Saussurea costus
• Family: Compositae
• Common Name: Costus, Kushta

Medicinal Importance

Costus is a highly valued medicinal herb with a wide range of therapeutic uses in traditional medicine systems such as Ayurveda, Chinese medicine, and Tibetan medicine. Key medicinal benefits include:

• Active Compounds: Roots contain diosgenin and steroidal sapogenins, which contribute to its medicinal properties.
• Uses:
  • Ayurvedic Medicine: Known for its tonic, stimulant, and antiseptic properties.
  • Traditional Chinese Medicine: Costus is one of the 50 fundamental herbs.
  • Tibetan Medicine: Used to treat conditions like swelling, difficulty in swallowing, pulmonary disorders, and muscle wasting.
• Therapeutic Benefits:
  • Anodyne (pain-relieving)
  • Antibacterial
  • Antispasmodic
  • Aphrodisiac
  • Carminative
  • Stomachic and tonic
  • Vermifuge (helps expel parasites)
• Other Uses:
  • The root is used to treat abdominal pain, chest pain, gall bladder issues, constipation, and asthma.
  • Hair Care: The essential oil of the root is used to darken grey hair.

Climate and Soil Requirements

• Climate:
  • Costus thrives in temperate and sub-alpine regions with high humidity.
  • The plant grows well in areas at altitudes ranging from 2000 to 3300 meters.
  • The minimum temperature required for cultivation is 13°C.
  • It prefers cool, moist environments with a minimum of frost.
• Soil:
  • Best suited for sandy loam soils rich in organic carbon and moisture.
  • Soil pH should be between 5.7 to 7.5.
  • Well-drained soils are essential to avoid waterlogging.

Propagation Methods

• Rhizome Cuttings:
  • Commercial cultivation is done mainly through rhizome cuttings, which are more efficient and productive.
  • The rhizomes contain multiple buds, with most of them concentrated around the stem scar and tips.
  • Rhizomes weighing about 40 g should be selected for planting.
• Seed Propagation:
  • Seeds are sown in cold frames in early spring.
  • The seeds should be lightly covered with compost or sown on the surface, ensuring moisture retention.
  • Once seedlings are large enough, they can be pricked out and grown in pots for the first winter. Transplant them in late spring after the last frost.
• Division: Mature plants can be divided in spring to propagate new plants.

Planting and Spacing

• Planting Time: Seeds are typically sown in April or May in a nursery. Once seedlings reach about 15 cm in height, they are ready to be transplanted to the field.
• Planting Method: Use ridges and furrows for planting. Rhizome spacing should be 50 cm x 50 cm, with a planting depth of 8-10 cm.
• Field Preparation: Prepare the field with adequate soil moisture and proper drainage to ensure optimal growth.

Irrigation Needs

• Watering Frequency: The crop requires 5-6 irrigations from May to September, especially during the sprouting stage. Ensure that irrigation is done at regular intervals, without overwatering the plants.
• Watering Method: Use drip irrigation or furrow irrigation to avoid waterlogging. Proper water management ensures good root development and overall plant health.

Manure and Fertilization

• Farmyard Manure (FYM):Apply 15 tonnes/ha of FYM to improve soil fertility.
• NPK Fertilizer: Apply 45:30:30 NPK (kg/ha) in two split doses to support the growth of the plant. The first dose is usually applied at planting time, and the second dose is applied after 2-3 months.
• Organic Fertilizers: Use organic or bio-based fertilizers to maintain soil health and promote sustainable farming practices.

Harvesting and Post-Harvest Management

• Harvesting: The roots of Costus are harvested after 2-3 years of cultivation when they have reached full maturity. The roots are typically harvested in early September, October, or early spring.
• Post-Harvest Handling: Once harvested, the roots are cleaned and dried for storage or further processing. Drying is an essential step to prevent spoilage and enhance the shelf life of the roots. The roots can be further processed into powder, essential oil, or used in incense making.
• Essential Oil Extraction: The roots can be distilled to extract essential oils which are highly valued in perfume making, incense production, and medicinal uses.

Yield

• Fresh Rhizomes: The expected yield of fresh rhizomes is about 28-30 tonnes per hectare.
• Dry Roots: The yield of dry roots is typically around 200-300 kg per hectare after 2-3 years of growth.

Challenges in Cultivation

1. Climate Sensitivity: Costus is sensitive to extreme weather conditions, particularly frost and drought.
2. Soil Health: It requires moist, well-drained soils; waterlogging or poor drainage can stunt its growth.
3. Pests and Diseases: While generally resilient, Costus may suffer from root rot if overwatered or exposed to high humidity.
4. Market Demand: There may be challenges in ensuring steady market demand for Costus roots and its processed forms.