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Good rutabaga roots always store better than poor ones. Good storage results require that high-quality roots are harvested from the field. Both cultural practices and weather affect quality.
Registered seed, soil preparation, spacing, fertilizer and spray programs, use of herbicides, boron and sprout-inhibitor sprays, etc all have an effect on the quality of the roots and their freedom from disease and disorders. For details on recommended practices, consult Ontario Ministry of Agriculture and Food Publication 502, Rutabagas.
The weather can affect the quality and storage behavior of roots. Too little rain will reduce the effectiveness of fertilizer applications and, in general, roots will be undersized. Nevertheless, the roots will have more flavor, be firmer, mature better and likely store better than roots grown in a wet year. Too much rainfall usually results in more storage problems. The roots are larger but less firm, more susceptible to mechanical injury and disease organisms, have less flavor, and their maturity at harvest is delayed. Immature roots do not store as well as properly matured ones.
Avoid excessive mechanical injury as much as possible. Bruises, cuts and scrapes exact a toll not only in appearance (the worst must be discarded) but also create focal points for disease organisms to enter and start rots. Furthermore, injured roots age at an increased rate, lose moisture faster and, in general, are a problem in storage. It is time well spent to study your harvesting and storage-filling operations for the purpose of reducing mechanical injuries.
Unlike potatoes and onions that require a curing treatment before storing, rutabaga roots should go immediately into storage after harvest. For best storage results, the roots are cooled at 0°C as soon as possible, and the relative humidity (RH) within the storage room must be maintained at a very high level (95%).
The rutabaga root, similar to that of carrots, beets and parsnips, has no special protection against loss of moisture by evaporation. Exposure to low RH results in excessive water loss and shriveling. Consequently, it is essential to maintain a very high RH in storage. During cooling of the roots there is a considerable loss of moisture, so cool the roots to 0°C as quickly as possible. At 0°C it is much easier to maintain the RH at a very high level than at higher storage temperatures. An undersized evaporator (cooling coil) in the storage room can defeat the aim of maintaining very high RH. Because it is undersized, it is necessary to operate at a temperature much lower than that of the room to absorb the heat load. Consequently, the evaporator acts as a dehumidifier and maintains the RH in the storage room at a much lower level than desired. Undersized evaporators may be able to maintain the desired temperature, but only at the expense of lowering the RH. When installing refrigeration equipment, growers should insist on proper-sized evaporators to ensure that the system is capable of maintaining both a 0°C temperature and a very high RH. Air-cooled systems should be equipped with adequate humidification systems.
There are many good reasons for storing rutabagas at 0°C. As mentioned previously, it is easier to maintain a very high RH at 0°C than at higher temperatures. The activities of disease organisms are sharply reduced as the temperature falls below 4°C, and at 0°C they are largely inactive. It has been proven that the brown surface discoloration called "storage burn" can be largely controlled by quickly cooling the freshly harvested roots to 0°C, together with adequate air circulation. A very important effect of storing at 0°C is that aging processes (chemical changes) are markedly slower than at high storage temperatures. The roots are firmer, have a better flavor, are more resistant to diseases, and have a longer shelf-life when marketed. Furthermore, roots do not sprout at 0°C. Storing at 0°C will slow down the development of soft rot and skin rot as well as retard the brown internal discoloration of roots affected with water core (boron deficiency). However, these diseases and disorders occur in the field and should be controlled there. Roots with disorders and diseases should never be placed in storage. Rutabagas freeze at approximately -1°C and temperatures below -0.5°C should be avoided in storage.
Waxing of roots to reduce moisture loss during storage is not recommended. The wax coating will become unsightly and it may interfere with the normal living processes of the roots which require oxygen intake and carbon dioxide release. In a proper storage maintained at high RH, moisture loss from the roots will be minimal and there is no need for waxing them.
However, roots being marketed should be waxed to enhance their appearance and protect them against excessive moisture loss. Details concerning the waxing of rutabagas may be obtained from Agriculture Canada Publication 1120, The Waxing of turnips for the Retail Market.
In past years, large quantities of rutabagas have been stored in pits, barns, common or air-cooled storages and, more recently, refrigerated storages.
Whatever your requirements for rutabaga storage, information on construction is available from your closest Agricultural Engineer in an office of the Ontario Ministry of Agriculture, Food and Rural Affairs.
For more information:
Toll Free: 1-877-424-1300