Cabbage is a popular vegetable throughout the world because of its adaptability to a wide range of climatic conditions and soil, ease of production and storage, and its food value. However, in commercial cabbage production, the farmer must pay special attention to all the factors and steps in production to realize profits. Moreover, it is a delicate vegetable crop, in spite of its adaptability to varying climatic and soil conditions.
Brassica oleracea var capitata
Suitable Varieties for Commercial Cabbage Production
Commonly grown varieties include Oxylus, Super Cross, Santa, Tropica Cross.
Source of Planting Material
Cabbage is propagated by the seed. For commercial cabbage production contact reputable seed dealers.
Climatic Requirements for cabbage production
Cabbage thrives in a moist climate. In Ghana, it can be grown anywhere. However, commercial cabbage production is mainly done in Southern Ghana particularly Akwapim and Kwahu areas. Cabbage is also cultivated in the moist high elevations around Tarkwa.
Selecting site for Commercial cabbage production
You can grow cabbage in a variety of soils with high organic matter throughout the year. However, during the dry periods of the year, you must ensure a reliable source of water supply. It thrives best in deep well-drained loamy soils.
According to Horticulture Development Unit (HDU-DCS), MOFA, you must thoroughly hoe or plough (30cm deep) and harrow your field. Furthermore, you must prepare ridges or plant beds where necessary on which you may transplant your seedlings. Then, you incorporate well-decomposed manure.
However, Dr Kofi Boa at HGBF | CNTA has demonstrated the possibility of growing cabbage on a No-Till (Conservation Agriculture) field. This method remarkably gives a better yield, reduces the cost of production and is very sustainable. In this case, the farmer, completely avoids “slash and burn”, ploughing and harrowing. Rather, the farmer maintains adequate soil cover for good water retention and many other benefits. Read more on conservation agriculture.
Establishing cabbage nursery
You can sow seeds on seed beds, in seed trays or seed boxes. You would require 0.3 kg of seed to cultivate 1 ha of cabbage. Prepare seed beds at 1.2m wide and any convenient length and then level beds. Water the bed, cover with a 4cm thick layer of dry grass or sawdust and burn to sterilize the soil. Alternatively, solarize soil by covering the soil with transparent plastic sheets for 5-8 weeks to sterilize the soil.
Sow seeds in drills 10cm apart. Cover beds with well dried non-seeded grass or palm fronds after sowing. After emergence, remove dry grass and provide shade over the bed. Thin out weak, malformed seedlings to avoid overcrowding. Prick out seedlings 6 to 7 days after emergence. Two weeks before planting out on the field, fertilize seedlings with NPK 15-15-15 liquid feed (Prepare the solution by dissolving 5g NPK in every 1 litre of water). Apply directly to the soil. Harden seedlings 1 week before transplanting by gradually decreasing shade until at least 1-day full exposure to sunlight and/or by reducing irrigation. Control pests and diseases by applying recommended fungicides and erect insect nets over seedlings.
Transplanting seedlings of cabbage
Transplant the seedlings 4 weeks after emergence on the field at the 5-leaf stage in the early morning or late afternoon. The planting distance for cabbage depends on the variety grown. Varieties which have larger heads require wider spacing. For most varieties, a planting distance of 45 to 60cm between rows and 45 to 60cm within rows will be adequate. Apply recommended fungicides 24-48 hours before transplanting and irrigate immediately after transplanting.
Irrigation should be provided as often as possible especially in the dry season. Poor irrigation results in poor yield. Ensure that adequate water reaches the root zone. To ensure good soil water retention, practice No-Till under Conservation Agriculture.
Fertilizer Application on cabbage field
Test your soil and use the analysis as a guide for fertilizer application. A general recommendation is to apply 40 to 50 tons/ha of decomposed farm yard manure, poultry manure or cow dung during ridging or bed preparation. At planting apply 15-15-15 NPK at 250kg to 400kg/ha (5g/plant). Two weeks after planting apply Sulphate of Ammonia at a rate of 80 to 100kg/ha (3g/plant) and repeat 6 weeks after planting.
Weed Control in cabbage
Regular shallow hoeing (to prevent root destruction) should be done to control weed growth. Where manual weed control is difficult, pre-emergent herbicides may be applied prior to transplanting. Follow manufacturer’s recommendation. Take precautions to avoid injuries from chemicals.
Pest Control in cabbage
The major pests found on cabbage include caterpillars, aphids, cabbage webworm, diamondback moth, mole cricket, snails and rodents. The insects can be controlled by the use of recommended pesticides. Remove outer leaves to prevent caterpillars from entering the head. Handpick snails and slugs and destroy them.
Root-knot nematode: Treat soil with suitable or recommended nematicide before planting. Practice crop rotation, another principle in conservation agriculture.
Disease Control in Cabbage
Black rot (Xanthomonas campestris): This is a bacterial disease causing greyish blotches on the leaves. Control by practising crop rotation with legumes and cereals. Ensure proper drainage of the beds and remove diseased plants and destroy them.
Damping off and Collar rot: The infected stem portion of seedling becomes discoloured and begins to shrink, resulting in loss of supportive strength, and the seedlings topple over and die. To prevent the occurrence, treat seeds with approved fungicides before sowing. In the nursery remove affected seedlings and treat beds with approved fungicides to control spread.
Bacterial soft rot (Erwinia sp.): Attack stem, root and underside of the leaves which become greyish brown and collapse. Control by rotation with tolerant crops.
Harvesting of cabbage
Heads can be harvested 7 to 8 weeks after planting and remains in the crop for 2 to 3 weeks. Cabbage should be harvested when the heads are full and hard. When harvesting, bend the plant over to one side and cut above the outer leaves using a sharp knife. Moreover, you should leave a few wrapper (outer) leaves around the head. Take care not to split the head.
Yield of cabbage
Cabbage yields a head of 0.45 to 2.5kg by weight depending on the variety grown. In commercial cabbage production, you can obtain yields of 30 to 40 tons/ha.
Post-harvest Handling of cabbage
Trim off the outer leaves, sort out and grade by sizes. Pack in crates or boxes and keep under well-ventilated shade. Avoid throwing the heads into a truck as poor post-harvest handling may lead to losses.
Cabbage must be hard, the head full and conveyed in appropriate containers.
Packaging of cabbage
You can packaged cabbage in containers such as cartons and crates.
Reference: Cabbage production (mofa.gov.gh)