Brassica oleracea Headed Cabbage (PROSEA)

Plant Resources of South-East Asia Introduction

List of species

Brassica oleracea L. cv. groups White Headed Cabbage, Red Headed Cabbage, Savoy Headed Cabbage

Protologue: Cv. group names are proposed here.

Family: Cruciferae

Chromosome number: 2n= 18

Synonyms

• Cv. group White Headed Cabbage: B. oleracea L. var. capitata L. f. alba DC. sensu Nieuwhof (1969), B. oleracea L. ssp. oleracea convar. capitata (L.) Alef. var. capitata L. f. alba DC. sensu Hegi (1986).

• Cv. group Red Headed Cabbage: B. oleracea L. var. capitata L. f. rubra (L.) Thell. sensu Nieuwhof (1969), B. oleracea L. ssp. oleracea convar. capitata (L.) Alef. var. capitata L. f. rubra (L.) Thell. sensu Hegi (1986).

• Cv. group Savoy Headed Cabbage: B. oleracea L. var. sabauda L. sensu Nieuwhof (1969), B. oleracea L. ssp. oleracea convar. capitata (L.) Alef. var. sabauda L. sensu Hegi (1986).

Vernacular names

• Headed cabbage (white, red or savoy), cabbage (white, red or savoy) (En)
• Chou cabus, chou de Milan (Fr)
• Indonesia: kol, kobis, kubis
• Malaysia: kubis
• Papua New Guinea: kapis
• Philippines: repolyo (Tagalog)
• Cambodia: spéi k'daôb
• Laos: kalampii
• Thailand: kalam-pli
• Vietnam: cải bắp.

Origin and geographic distribution

Headed cabbage evolved in north-western Europe during the early Middle Ages from leafy unbranched and thin-stemmed kales (often classified as B. oleracea L. var. acephala DC.), which spread in Roman times from the Mediterranean area, where B. oleracea var. sylvestris L. and other related species occur naturally in coastal areas. Whereas the primitive types were primarily originally cultivated for medicinal purposes, headed cabbage had become one of the most important vegetables in 16th Century Europe. From then onwards cabbage was introduced worldwide, but in tropical and subtropical areas commercial cultivation is still mostly restricted to the cooler climates of the highlands or to the mild cool seasons at higher latitudes.

Uses

In tropical Asia the importance of cabbage, mainly early maturing white cabbage with firm and round to flat heads (1-2 kg), is rapidly increasing. It can be fairly easily produced in large quantities, transported over great distances without much damage and stored for several weeks. It has partly replaced the more perishable leafy vegetables, particularly in city markets. Cabbage is usually consumed as a cooked or fried vegetable, sometimes pickled or preserved by steaming and drying. It is often eaten fresh as an ingredient of coleslaw (a salad made of raw sliced or chopped cabbage) and mixed salads. Late maturing and large-headed (3-5 kg) cultivars are processed into sauerkraut. The prominence of white cabbage as a vegetable is gradually declining in western Europe .

Production and international trade

Total area annually planted with cabbage worldwide is at least 800 000 ha: 200 000 ha in the former Soviet Union, 180 000 in eastern Europe, the Balkans and Middle East, 40 000 ha in western Europe, 100 000 ha in the Americas and 280 000 ha in Asia (excluding China).

In Indonesia the area of white cabbage increased from 24 000 ha in 1975 to 41 000 in 1990 with a total production of 820 000 t. Thailand has about 7 000 ha, the Philippines 6600 ha, Malaysia 1000 ha. White cabbage is also important in India (83 000 ha), Japan (42 000 ha), South Korea (41 000 ha) and Taiwan (10 000 ha).

Almost all white cabbage in Asia is produced for local (urban) markets. Singapore imports annually some 16 000 t white cabbage from Indonesia, mainly from the Karo highlands in northern Sumatra. Singapore is also supplied from the Cameron highlands in Malaysia.

Properties

White cabbage has a good nutritional value, although less than many green leafy vegetables. Per 100 g fresh edible portion it contains on average: water 91 g, protein 1.6 g, carbohydrates 6 g, fibre 0.8 g, Ca 55 mg, Fe 0.8 mg, vitamin C 50 mg. Dry matter content is 7% for most white cabbage grown in Asia, but is 10-11% in long-storage types of north-western Europe.

All Brassica L. crops contain glucosinolates which in crushed leaves are broken down by the enzyme myrosinase to give bitter-tasting, antimicrobial but also goitrogenic substances. In white cabbage glucosinolate content is very low (100 mg per 100 g) as a result of centuries of selection against bitter-tasting plants. The 1000-seed weight is 3-5 g.

Description

• Biennial herb, 40-60 cm tall at the mature vegetative stage, 150-200 cm tall when flowering in the second year.
• Mature plants have a strongly ramified system of thin roots, 90% in the upper 20-30 cm of the soil but some laterals penetrating downward to 1.5-2 m depth.
• Stem unbranched, 20-30 cm long, gradually thickening upward.
• Basal leaves in a rosette of 7-15 sessile outer leaves, each 25-35 cm × 20-30 cm; upper leaves in a compact flattened globose to ellipsoid head, 10-30 cm in diameter, formed by a great number of overlapping fleshy leaves around the single growing point; leaves glabrous, coated with a layer of wax, grey- to blue-green in the rosette and light-green to creamy-white inside the head (white headed cabbage); leaves red-purple in red headed cabbage, green to yellow-green and puckered in savoy headed cabbage.
• Inflorescence a 50-100 cm long raceme without bracts on the main stem and on axillary branches of bolted plants; pedicel 1.5-2 cm long; flowers tetramerous, bisexual; sepals erect, light-green; petals spathulate, 25 mm × 10 mm, yellow; stamens 6, 2 short and 4 long; ovary superior with false septum and 2 rows of campylotropous ovules; nectaries 2, situated between the base of the ovary and the short stamens.
• Fruit a silique, 5-10 cm × 0.5 cm, containing 10-30 seeds.
• Seed globose, 2-4 mm in diameter, brown. Germination is epigeal.
• Seedlings have a thin taproot and cordate cotyledons; the first true leaves are ovate with a lobed petiole.

Growth and development

Seeds germinate within 3-6 days and seedlings have 4 true leaves 4-5 weeks after sowing at 15-20 °C average daily temperatures. The first 7-15 leaves expand and unfold to form a rosette, commonly called the frame. Subsequent leaves only partly unfold, forming the shell of the head; the growing point increases in size, the stem thickens and the head is filled out with fleshy leaves. The head is solid and ready for harvesting 80-120 days after germination, depending on genotype and climate.

Most cabbage types require 6-8 weeks exposure to temperatures below 10 °C for flower initiation and bolting. The main stem increases in length rapidly, causing the head to burst, and branches into a number of racemes. Flowering starts at the base of the racemes, 2-3 months after the first sign of bolting and continues for 4-5 weeks. Sporophytic self-incompatibility (1-locus system with multiple alleles) precludes natural self-fertilization. Insects, especially bees, effect cross-pollination. Seeds are mature 8-10 weeks after anthesis.

Other botanical information

Several hundreds of cultivars of white cabbage are grown worldwide. In the market gardens of tropical Asia early-maturing compact and round- or flat-headed F₁ hybrids have almost completely replaced the open-pollinated cultivars such as "Golden Acre", "Copenhagen Market", "Glory of Enkhuizen" and the flat-headed "Drumhead". F₁hybrids are predominantly of Japanese origin: "Green Boy" (="Gloria Osena"), "Titan", "Green Coronet", "Summer Autumn", "F₁ KK", "F₁ KY", etc. Seeds of all these cultivars are imported from temperate regions.

"Yoshin" and "Shanghai" are early-bolting Indonesian cultivars, seed of which can be produced locally on Java. These cabbages are sweet-tasting, but the heads are too loose for market gardening and long-distance transport.

Red cabbage and savoy cabbage are not very common in South-East Asia, and of economic importance mainly in Europe and America.

Ecology

Cabbage grows best at average daily temperatures of 15-20 °C and a diurnal variation of at least 5 °C. In tropical regions these conditions are only met in highlands above 800 m. At temperatures in excess of 25 °C young plants still grow well, but subsequent head formation will be retarded. Some Japanese F₁hybrids are more heat-tolerant, but even these do not perform so well under tropical lowland conditions.

Most cabbage cultivars are daylength neutral and flower initiation is mainly induced by low temperatures. Half-grown cabbage plants can even withstand short spells of frost (-5 °C).

Soils should be well-drained and fertile, having good moisture retaining capacity, high organic matter content and a pH of 6.5-7.5. Because of its shallow root system, cabbage needs a regular supply of water throughout the growing season either by rain or irrigation. Evapotranspiration of a fully-grown cabbage field can reach 4 mm per day.

Propagation and planting

Dry cabbage seed (6% moisture content) will remain viable for at least 4-6 years when stored dry at temperatures below 18 °C. Freshly harvested seed sometimes gives poor germination. Soaking overnight and rinsing with water overcomes this. After 3-4 months storage dormancy disappears. Seeds are sown on seed-beds, in pots or in trays; young seedlings may require protection from excessive sunshine by light shading. About 300 g seed and about 200 m²of seed-bed are required for 1 ha of cabbage. Transplanting to the field takes place 4-5 weeks later, when the seedlings have 4-6 true leaves. Plant densities of 30 000-50 000 plants per ha are usually applied and spacing is 40-50 cm × 55-60 cm. Head size can be largely regulated by adjusting plant density.

Lateral shoots from decapitated stumps can be rooted and transplanted. This method of vegetative propagation is practised in breeding programmes to maintain selected plants. A tradition on Java of multiplying some old loose-headed varieties (e.g. "Wonosobo" and "Argalinga") by cutting, has virtually disappeared.

Husbandry

Cabbage crops are often grown in rotation with maize, rice, potato, legumes and tobacco. Soil preparation includes deep digging, mixing with compost or stable manure (20-50 t/ha), followed by fine tillage. Before planting NPK fertilizer is applied and for good vegetative growth dressings with N fertilizer are given when head formation starts. Type and quantities depend on soil type, initial nutrient reserves in the soil and yield level. The uptake and removal of nutrients is very high. A cabbage crop with a yield of 25 t/ha absorbs approximately 140 kg N, 40 kg P, and 180 kg K. Growing cabbage on ridges during the wet season improves drainage. The crop should be kept free of weeds, especially in the first month after transplanting. Mulching with rice straw is beneficial to growth.

Diseases and pests

The most important diseases in tropical areas are: grey leaf mould (Alternaria brassicae) and downy mildew (Peronospora parasitica), which can be controlled by fungicides and selection of tolerant cultivars; bacterial soft rot (Erwinia carotovora) under hot and humid conditions; black rot (Xanthomonas campestris pv campestris), controlled by disease-free seeds and seedlings (some cultivars have a good level of tolerance); clubroot (Plasmodiophora brassicae), prevented by wide crop rotation, by liming and cultivation on soils with pH > 7, and by stimulating antagonistic fungi in the soil (promising experimental results in West Java with Mortierella spp.). Clubroot is spreading fast during the last decades and has become the most detrimental disease in many highland areas. Cultivars with durable resistance to clubroot are not yet available. Other diseases: ring-spot (Mycosphaerella brassicicola), cabbage yellows (Fusarium oxysporum), which can be controlled by crop rotation and resistant cultivars; cauliflower and turnip mosaic virus, which can be prevented by control of the aphid vectors and by eradicating hosts like wild mustard. Alum dusted on stumps has been found effective in controlling storage rots caused by Erwinia.

Important pests include: diamond-back moth (Plutella xylostella) for which chemical control is increasingly ineffective because of the quick build-up of resistance to all categories of insecticides, whereas biological control with BT (Bacillus thuringiensis preparates), sex pheromones and parasitoids (Diadegma semiclausum in cool climates, Apanteles plutellae in hotter climates) is promising; leaf webber (Crocidolomia binotalis). Occasional pests are webworm (Hellula undalis), cutworm (Spodoptera littoralis), flea beetle (Phyllotreta spp.), cabbage butterfly (Pieris canidia) and cabbage aphid (Brevicoryne brassicae). Indian mustard (Brassica juncea (L.) Czernjaew) may be used as trap crop for diamond-back moth and other pests when planted in rows between cabbage; chemical control can then be restricted to the mustard plants.

Harvesting

Well filled-out and solid heads are cut, usually with a few wrapper leaves attached, 2-3 months after transplanting. The period of harvesting is 1-2 weeks, F₁ hybrids maturing more uniformly than open-pollinated cultivars.

In Thailand the lateral shoots from decapitated stumps are sometimes harvested as a sort of loose-leaved Brussels sprouts.

Yield

Open-pollinated cultivars yield 10-15 t/ha, F₁ hybrids 40-60 t/ha under optimum growing conditions. In tropical regions yields are generally highest above 800 m altitude.

Seed yields are 200-1000 kg/ha in temperate climates.

Handling after harvest

Cabbage can be stored for 7-10 days in a cool (20 °C), well-aerated and dark space. Transportation can be in ventilated boxes, net bags or lightweight Hessian sacks. At 1 °C and high humidity (95-98%) cabbage can be kept for 2-3 months.

Genetic resources

Working and germplasm collections of white cabbage and other Brassica crops are available in several research centres in Europe, Commonwealth of Independent States (Vavilov Institute, Petersburg), United States, India, Malaysia, Japan, etc. Preservation of germplasm from the centres of genetic diversity (Mediterranean region) appears adequate.

Breeding

Present breeding programmes aim at F₁ hybrids based on single crosses between inbred lines. Inbreeding is effected by bud-pollination or treatment with CO₂ (2-10%) before bee pollination to temporarily break the self-incompatibility.

Main breeding objectives include: head shape and size, internal firmness, leaf configuration and colour, core (= internal stem) length, taste, vitamin C content, earliness, standing ability (delayed splitting of the head at maturity), productivity, heat tolerance, resistance to diseases, pests and tip burn (physiological disorder).

Prospects

The importance of white cabbage will further increase in South-East Asia. Heat-tolerant cultivars enable cultivation at lower elevations, but market gardening will continue to prevail in the highlands because of higher yield potential, better head quality and fewer diseases and pest problems. Considerable progress is being made with effective methods of integrated pest management in cabbage (Malaysia, Indonesia, Taiwan) and this will reduce pesticide use. Cultivars resistant to cabbage yellows and black rot are increasingly becoming available. However, clubroot is spreading fast in areas with intensive market gardening and cultivars with durable resistance will not be available in the medium term. Methods of control by antagonists to the pathogen deserve more attention.

The development of DNA markers by plant biotechnology for more precise indirect screening for resistance to diseases and pests, as well as other characteristics, will considerably increase breeding efficiency in cabbage. Cytoplasmic male sterility might eventually replace self-incompatibility as a more reliable technique for hybrid seed production, but a number of physiological problems have to be overcome.

Literature

• Bos, G. & Sjarifudin S., 1977. Varietal screening trials of white cabbage, cauliflower and chinese cabbage on Java. Bulletin Penelitian Hortikultura [Horticultural Research Bulletin] 5(6): 71-91.
• Bull, P.B., 1982. Horticultural note No 3: Cabbage. Harvest (DPI Konedobu, Papua New Guinea) 8(3): 122-125.
• Dickson, M.H. & Wallace, D.H., 1986. Cabbage breeding. In: Bassett, M.J. (Editor): Breeding vegetable crops. Avi Publishing Company, Westport, Connecticut, United States. pp. 395-432.
• Grubben, G.J.H., 1977. Tropical vegetables and their genetic resources. Tindall, H.D. & Williams, J.T. (Editors). International Board for Plant Genetic Resources (IBPGR), Rome, Italy. pp. 81-90.
• Nieuwhof, M., 1969. Cole crops. Leonard Hill, London, United Kingdom. 353 pp.
• Talekar, N.S. (Editor), 1992. Proceedings of the second international workshop on the management of diamondback moth and other crucifer pests (10-14 December, 1990). Asian Vegetable Research and Development Center (AVRDC), Tainan, Taiwan. AVRDC Publication 92-368. 603 pp.
• Tindall, H.D., 1983. Vegetables in the tropics. MacMillan, London, United Kingdom. pp. 120-123.
• Tsunoda, S., Hinata, K. & Gomez-Campo, C. (Editors), 1980. Brassica crops and wild allies: biology and breeding. Japan Scientific Societies Press, Tokyo, Japan. 354 pp.
• Villareal, R.L., 1987. Genetic improvement of tropical and sub-tropical vegetable crops. Philippine Journal of Crop Science 12(3): 131-138.

See also the species page

Authors

• H.A.M. van der Vossen