Storage of Cabbage
Table of Contents
Cabbage intended for long-term storage is harvested and moved into storage during the months of October and November. This stored cabbage is marketed throughout the winter and spring up to late May. The storage life of cabbage will depend on cultivar and growing conditions. For an updated list of cabbage varieties suitable for long-term storage, consult Ontario Ministry of Agriculture, Food and Rural Affairs Publication 363, "Vegetable Production Recommendations."
For best storage results, cabbage should be harvested in a slightly immature stage. Such heads will retain their green color for a longer period of time in storage than will fully mature cabbage. Cabbage should be harvested before the top cover leaves begin to lose their bright green color. Varietal selection, growing conditions and cultural practices will affect the maturity date.
Frost is quite commonly encountered during the fall harvest season. Cabbage can sustain a number of light frosts with little damage. If the heads are frozen, harvesting should not commence until the frost is out since frozen cabbage is more prone to mechanical injury. Cabbage which has been subjected to a number of frosts usually will not store as well and should be marketed first.
Field heat should be removed as quickly as possible to ensure maximum storage life. The best results are obtained where a temperature of 0°C (32°F) can be maintained. It is much easier to maintain both the temperature and relative humidity at the optimum level in refrigerated storages than in common or unrefrigerated storages.
Continued ventilation in a common storage, to obtain the desired storage temperature, usually leads to low humidity. Consequently, most operators of common storage harvest later in the fall when the outside air temperature is closer to the desired storage temperature.
There are a few Filacell type storages in Ontario. This type of storage can easily be set to maintain both the relative humidity and temperature at the recommended level.
When placing cabbage into the storage it is desirable to arrange the heads to allow for maximum air flow and quick even cooling. Since most cabbage is stored in pallet bins, loading arrangements can be made to allow for air channels between stacked rows within the storage, which will promote better air circulation.
A cabbage is approximately 92% water. From the time of harvest it is important to cool the cabbage as quickly as possible and maintain a relative humidity of at least 90% or higher. Relative humidities below 80% will result in moisture loss and unacceptable shrinkage of the heads. Measuring the relative humidity in the storage can be easily done with a hydrometer. Where the relative humidity is low, and the cabbage is off the floor in containers, wetting of the storage floor will help to raise the humidity.
It is best to store cabbage by itself. Cabbage should never be stored with fruit, especially apple, even if the temperature and relative humidity is similar. Fruits and some vegetables give off ethylene gas in storage which will cause the cabbage to discolor. Ethylene also causes individual leaves to form abscission layers where the leaf stalk joins the core. The leaves will subsequently fall off and the heads will be unmarketable.
Further information can be obtained from OMAF Factsheet "Storage Incompatibility", Agdex 202/65.
Most cabbage producers prefer to use pallet boxes to store cabbage in since these containers facilitate both the loading and unloading of the storage. Pallet boxes can be easily arranged in the storage to maximize air circulation which greatly improves the maintenance of an even temperature throughout the storage.
When not in use pallet boxes should be stored outside and subjected to the sun and light to control fungi which develop on the wood. This fungi can cause the staining of cabbage in storage.
Cabbage can be stored in bulk successfully if carefully handled and piled to a depth of no more than 1.5 metres with ample aeration of the pile using forced air.
Consultation with a seed supplier, Horticultural Crop Advisor or Publication 363, Vegetable Production Recommendations is recommended to obtain the most recent information on the best recommended storage varieties of cabbage for Ontario. For the fresh market it is important to grow varieties which will retain their green color in storage. Retention of green color is not as important for varieties to be used for coleslaw production.
Handling and Storage
It is important to handle the heads carefully to prevent bruising. Any damage sustained by the cabbage head will result in increased susceptibility to disease organisms. Before storage all dead, damaged and diseased leaves should be removed. Any heads showing disease symptoms should be discarded, since diseases can spread from head to head in storage.
Field Diseases on Cabbage in Storage
Since most storage disease problems begin in the field, good disease prevention must begin with disease control in the field. By following recommended cultural practices such as using hot water treated seed, proper seedbed or seedling house sanitation, use of disease-tolerant varieties, good crop rotations and the application of proper pesticide sprays for weed, insect and disease control, disease problems can be greatly reduced.
Botrytis Leaf Mold
This disease is favored by temperatures above 2°C (35°F), high relative humidities of 95% or more and by poor air circulation. This disease is characterized by small brown patches on the outer leaves and can cause serious losses.
Prevention can be obtained by careful handling to prevent wounding and bruising of the heads, maximizing the air circulation in the storage and by cooling and maintaining the cabbage to 0°C (32°F) as quickly as possible.
Alternaria (Black Leaf Spot)
High temperatures and wet conditions in August and September favor the spread of this disease which appears as a brown to black circular targeted spot on the leaves. Use of a fungicide as outlined in OMAF Publication 363, Vegetable Production Recommendations will help to reduce this disease problem. Cabbage leaves with alternaria should be trimmed in the field before storage.
This disease is favored by cool temperatures (l0°-15°C) and moisture. The disease appears as purplish irregular spots on the head with or without mildew on the leaves. Control can be obtained by applying an fungicide outlined in OMAFRA Publication 363, Vegetable Production Recommendations.
This disease can originate in the seed, in infected seedling flats or in infected cole crop residue. Since this is a bacterial disease, the best control is through the use of hot water treated seed, proper crop rotation and proper sanitation of seed beds or seedling flats.
Leaves infected with black rot should be trimmed off in the field. Where the disease has become systemic in the main stem, appearing as a blackening of the vascular bundles, the cabbage should not be placed in storage.
For further information on disease of crucifer crops, see OMAF Factsheets, Bacterial Diseases of Cruiciferous Crops, Agdex 252/635, and Fungal Diseases of Cruiciferous Crops, Agdex 252/635.
Nonpathogenic Disorders of Cabbage
Internal Tipburn is a problem associated with the death of leaf tissue usually along the leaf margins in the interior of the head. At first the tissue turns a light brown and may eventually appear dark brown to black taking on a papery appearance. This is an internal problem which can only be detected by cutting the cabbage heads open. This physiological disorder is associated with the plants inability to move sufficient calcium to the young actively growing inner leaves. The severity of Tipburn is influenced by weather conditions and the variety.
Pepper spot is another physiological disorder which usually shows up only after the cabbage has been stored under cool conditions for a period of time. It is suspected that temperature fluctuations and cultural conditions promoting vigorous growth increase the plants susceptibility to pepper spot. In New York state high rates of potassium in the soil have been shown to reduce the severity of this nonparasitic disorder. Varieties appear to differ in their degree of susceptibility.
To date virus diseases have been insignificant in Ontario. Turnip Mosaic Virus has been found in some cabbage in both New York and Ontario. However, this particular virus has not been a problem in Ontario.
With the use of disease-resistant varieties, better cultural practices and modern refrigerated storages, Ontario cabbage producers can market cabbage for up to 10 months or more of the year.
For more information:
Toll Free: 1-877-424-1300
Local: (519) 826-4047