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Post-Harvest · Post-harvest operation

Curing (Roots, Tubers & Bulbs)

Also known as: Wound healing, Skin set, Suberisation

Curing is a short conditioning period, at warm temperature and usually high humidity, that heals harvest wounds and sets the skin of roots, tubers, and bulbs so they resist water loss and decay in storage.

Dated referenceLast reviewed: 2026-07-13Updated: 2026-07-13
Illustrative diagram · AgricultureID (original)

Curing is the deliberate holding of freshly harvested roots, tubers, and bulbs under conditions that let their surfaces heal before storage. Lifting and handling inevitably cause cuts, bruises, and skinning, and these injuries are entry points for decay and routes for water loss. During curing the crop is held so that wounds heal and the skin firms, greatly improving how well the crop then stores.

For potatoes and sweet potatoes, curing encourages the wound periderm to form and the skin to set; for bulb crops such as onions and garlic, an analogous drying of the neck and outer scales seals the bulb. The precise conditions differ by crop — sweet potatoes and yams are cured warm and humid, potatoes somewhat cooler, and onions by drying — but the purpose is the same: a sound, sealed surface before long storage.

Why curing improves storage

Freshly lifted roots and tubers have delicate, easily damaged skins and unhealed wounds from harvest. Held under warm, humid conditions for a short period, they form a protective wound periderm over cuts and the outer skin toughens (a process related to suberisation). This healed, set surface strongly reduces both moisture loss and the invasion of decay organisms, so a cured crop keeps far better than an uncured one.

Curing is therefore best thought of as the bridge between harvest and storage: a crop that is cured well enters storage with sound surfaces, while one put straight into store with fresh wounds is far more likely to rot or shrivel.

Curing by crop group

Potatoes
Held warm and humid for a short period after harvest to heal wounds and set skins before cooling to storage temperature.
Sweet potatoes and yams
Cured at warm temperature and high humidity, which promotes rapid wound healing and much longer storage life.
Onions and garlic
Cured by drying the necks and outer scales, in the field or with warm moving air, to seal the bulb against moisture and decay.

Because the ideal temperature and humidity differ between these groups, curing conditions are matched to the crop. What they share is that curing precedes, and is distinct from, the cooler holding temperatures used for long-term storage.

Good practice

  • Cure soon after harvest, before wounds can become infected.
  • Use the warm, humid conditions appropriate to root and tuber crops, or drying conditions for bulbs.
  • Provide airflow to remove excess moisture and heat and to keep conditions even.
  • After curing, cool roots and tubers to their storage temperature; store cured bulbs dry.

Relationships

Evidence-backed connections in the knowledge graph.

Related topics

Scope & limitations

Geographic scope: Global. Curing conditions differ by crop and are adapted to local climate and storage facilities.

  • Optimum curing temperature, humidity, and duration are crop-specific; this entry gives principles, not exact settings.
  • Root and tuber curing (warm, humid) and bulb curing (drying) are distinct processes and must not be confused.
  • Curing improves storage but cannot compensate for severe harvest damage, disease, or poor storage conditions afterwards.

Sources

This article draws on the following authoritative sources. See our sources & methodology for how they are selected.

  1. [1]USDA ARS — Agricultural Research Service (opens in a new tab)

    USDA Agricultural Research Service (ARS)

    Authoritative

    Cited for: Curing and wound healing of roots, tubers, and bulbs

    Type:
    Government agency
    Jurisdiction:
    United States
    Accessed:
    2026-07-12
  2. [2]CIP — International Potato Center (opens in a new tab)

    International Potato Center (CIP)

    High

    Cited for: Curing of potato and sweet potato for storage

    Type:
    Research institute
    Jurisdiction:
    Global
    Accessed:
    2026-07-12
  3. [3]FAO — Food and Agriculture Organization (opens in a new tab)

    Food and Agriculture Organization of the United Nations (FAO)

    Authoritative

    Cited for: Curing in post-harvest handling of roots, tubers, and bulbs

    Type:
    Intergovernmental organization
    Jurisdiction:
    Global
    Accessed:
    2026-07-12

Related topics