AgriGuide

Cabbage

Cabbage (Brassica oleracea L. convar. capitata var. capitata) is one of the world’s most important vegetables, especially in the temperate zone. Most processed cabbage goes for the production of sauerkraut.

Suitable varieties for organic production

Hybrid varieties are most dominant and suitable in organic farming. While both white and red cabbages exist, the white variety dominates the market. Farmers should carefully choose from the available varieties in the local market, depending on their resistance to heat and cold as well as a number of important diseases and physiological disorders. Growth period differs from 75 days for early varieties, 90 days for mid-season, to over 120 days for late large-headed varieties (from seed to maturity).

Field selection

With respect to the selection of an appropriate field before planting cabbage, farmers should consider the following important factors, which affect a number of diseases such as club root and Sclerotinia:

• The field should have been free of crucifer crops or related weeds for at least 2 years, preferably 4. Crucifer crops include cabbage, cauliflower, broccoli, kale, kohlrabi, Chinese cabbage, mustards, turnips, rutabagas, radishes, etc. Cruciferous weeds include wild radish, shepherdspurse, wild mustards, etc. Crucifer plant waste should not be dumped on these fields.
• Fields with club root in the past needs strict control of soil pH (over 6.5). Application of lime some weeks before planting the cabbage seedlings is reported to reduce infection.

Harvest and post-harvest handling

Handling

Cabbage for processing should be delivered to the processor soon after harvesting. Heads should be harvested when firm and before they split or burst. In harvesting for fresh market, leave 4-6 wrapper leaves attached to the head. Wrapper leaves are removed when harvesting for kraut.

Storage

Store cabbage at 0°C and relative humidity of 98 to 100%. If stored under proper conditions, late harvested cabbages should keep for 5 to 6 months. Early-crop cabbage has a storage life of 3 to 6 weeks. Cabbage is held in common storage, where a fairly uniform inside air temperature of 0 to 1.6°C can be maintained. Cabbage wilts quickly if held under storage conditions that are too dry; hence, the humidity should be high enough to keep the leaves fresh and turgid. The storage life of late cabbage can be extended for several months if it is held in an atmosphere with 2.5 to 5% oxygen and 2.5 to 5% CO2. Cabbage should be handled carefully from field to storage, and only solid heads with no yellowing, decay, or mechanical injuries should be stored. Before the heads are stored, all loose leaves should be trimmed away; only three to six tight wrapper leaves should be left on the head. Loose leaves interfere with ventilation between heads, and ventilation is essential for successful storage. Upon removal from storage, the heads should be trimmed again to remove loose and damaged leaves. Cabbage should not be stored with fruits emitting ethylene such as, for example, bananas, dates and mangoes.