Ginger Crop Guides
Postharvest Handling of Ginger
The following is excerpted from "Product Specifications and Postharvest Handling for Fruits, Vegetables and Root Crops Exported from the Caribbean", by Dr. A.P. Medlicott (Fintrac). Unauthorized duplication is prohibited.
Ginger Zingiber officinale Roscoe
 Ginger Packed for Export
Chief Producers
St. Vincent, Dominica, St. Lucia, Jamaica.
Season
January to June
Quality Criteria
High quality ginger is characterized by large thick rhizomes with limited branching, white in color and glossy in appearance.
Variety
Any variety which produces large rhizomes of light colouration (preferably Hawaiian type).
Post-Harvest Handling
Ginger may be successfully stored for two months if the correct post-harvest handling and storage procedures are utilised.
Harvesting
Ginger should be harvested after the leaves have died (seven to nine months after planting) and the ginger root has fully matured. Internal flesh colour should be pale yellow. Delaying harvesting after maturity is reached will reduce the rhizome quality, decrease the storage life and increase the incidence of sprouting during storage. Rhizomes are harvested carefully by hand using a fork or cutlass to lift and break the soil. Harvesting during very wet or very dry conditions is to be avoided as this will reduce the ease of harvesting and increase the level of potential damage.
Field crates are required for transport of ginger from the field to the packhouse. Sacks or bags are unsuitable. The level of breakage during handling and transport in sacks is substantially higher than in the field crates. The level of rejection during grading will therefore be higher.
Market requirements demand that rhizomes be large and well-formed with limited branching. Outgrading should be carried out in the field to remove rhizomes that do not immediately attain the export specifications. Grading is also required prior to packing to remove broken or damaged rhizomes which occurred during field transport and handling.
The rhizomes should be washed as soon as possible after harvesting as soil is more difficult to remove when dry. Each rhizome should be washed in water. A high pressure hose, coconut fibre or a soft brush and copious water can be used to give a fresh appearance. Care is required during this operation to prevent breakage. After washing, a ten second dip treatment in 100 ppm sodium hypochlorite is preferred. This will assist in minimizing microbial damage and may improve presentation. After washing and dipping, rapid drying is required, preferably in field crates in a well ventilated area. Prolonged periods of drying in sunlight is to be avoided as water loss and shriveling will occur.
Export Grading and Packing
Ginger is loose packed in layers. Size grading is not usually carried out within cartons, assuming that all rhizomes meet tlle required size specifications. In some cases, size grading is carried out where different grades of ginger are being exported. For sea-shipment an additional 5% weight is required to account for weight loss during transport. Net weight requirements vary from 12 to 13.6 kg (27 to 30 lbs) depending on the market and importer requirements. Cartons must not be over-fllled during packing.
Packaging
Two-piece full telescopic fibreboard carton ("banana" type); burstng strength 275 lb/in2. Where staples are used for carton construction, care should be taken to ensure full staple closure to avoid rhizome damage.
Carton internal dimensions: 20 x 51 x 34 cm (7.9" x 20" x 13.4")
Storage and Transportation
For long term storage of ginger, it is recommended to treat with a fungicide in addition to sodium hypochlorite. Thiabendazole 0.05% for thirty seconds may assist in reducing spoilage incidence. The treatment should be given after washing and prior to drying.
Low temperature
Storage of ginger may be carried out at 12°C, 65 to 75% relative humidity, with the rhizomes remaining in a marketable condition for two to three months depending on the initial quality. Prolonged storage under ambient conditions (25° to 30°C) will result in high moisture loss, surface shriveling, discoloration and sprouting. Low temperature storage during shipment is preferable. However, as shipments from the Caribbean are generally made in containers without refrigeration (dry and ventilated), exports should optimally be made within seven days of harvesting and washing.
Potential Post-Harvest Losses
Mechanical Damage
Broken, split or bruised rhizomes are susceptible to disease incidence and water loss. Careful handling is therefore required during grading, packing and transportation.
Low Temperature
Storage at temperatures below 10° to 12°C will result in chilling injury characterized by skin discolouration, high levels of water loss and increased incidence of spoilage organisms.
Pathological Factors
Disease incidence in ginger is normally the result of poor handling, resulting in mechanical damage and water loss or incorrect storage environment. Losses from diseases are generally as a result of superficial mould or soft rots on rhizomes where breakage has occurred. Recommended storage environments, post-harvest treatments and careful handling will assist in minimizing the disease incidence.
Ginger Specification
Market
UK, Holland, U.S.A, Canada.
Characteristics
Large, thick rhizomes with limited branching, white, glossy and clean.
Size
- Minimum: 250 g (9 ozs)
- No maximum
- The main stem should be not less than 3 cm (1 1/4") thick, 12 cm (8") long
Appearance
- Well cleaned, bright, not immature, not old, stale, wilted nor sprouting
- Free from bacterial rot of fungal infection
- Excessive branching avoided
Market Requirements
Only high quality, large, white, glossy ginger is in demand on the export market The optimum marketing period for Caribbean ginger where quality is highest and market conditions more favourable, is January to March. Net weight of the carton is of prime importance for market compatibility and competitiveness.
Handling in Importing Country
During the winter months in importing countries, exposure of ginger to low temperature ambient conditions is to be avoided. Optimum storage temperatures for maximising the shelf life and quality are 10° to 12°C. Ginger can be stored with other commodities with no detrimental effect of product quality.
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