🍠 Medicinal Yam

Medicinal yam is a key steroid-bearing medicinal crop cultivated for diosgenin-rich tubers used in pharmaceutical synthesis.

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Crop Importance and Species

Dioscorea species are valued for diosgenin, a precursor for steroid drugs. Important medicinal species include D. floribunda, D. deltoidea, and related species.

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Climate and Soil

The crop prefers tropical to subtropical environments with moderate to high rainfall and well-drained light to medium soils.

Best range:

• Soil pH around 5.5 to 6.5
• Avoid very heavy clay and poorly drained fields.

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Propagation and Planting

Commercial planting is mainly through tuber pieces.

Options:

• Crown pieces (fastest sprouting)
• Median/tip pieces (slower sprouting)
• Seed and single-node cutting methods for multiplication, not primary commercial method.

Recommended points:

• Use healthy setts.
• Treat cut surfaces against rot.
• Plant with support/staking system for vines.

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Crop Management

Important practices:

• Provide pandal/trellis support.
• Timely weeding during early weak-vine stage.
• Organic matter-rich nutrition plus NPK schedule.
• Supplemental irrigation in dry spells.
• Intercropping with legumes possible.

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Duration, Harvesting, and Yield

Diosgenin and tuber yield improve with age; a 2-year crop is generally more economical than a 1-year crop.

Harvest notes:

• Harvest in dry season.
• Tubers are dug manually due to depth.
• Typical fresh tuber yields are high under good management.

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Summary Cheat Sheet

Topic	Exam Key Point
Main active compound	Diosgenin
Economic part	Tuber
Preferred pH	5.5 to 6.5
Best commercial propagation	Tuber pieces
Better economics	2-year crop
Support system	Pandal/trellis required

References

2 sources • [1] [2]

[1]

Indian Council of Agricultural Research (ICAR)

Official

[2]

ICAR-IIHR

Official