Cichorium endivia (PROSEA)
- Protologue: Sp. pl.: 813 (1753).
- Family: Compositae
- Chromosome number: 2n= 18 (36)
- Endive, escarole (En)
- Cichorée frisée, cichorée scarole (Fr)
- Indonesia: andewi
- Philippines: endiba (Tagalog), eskarola (Bisaya)
- Thailand: phakkat-foi.
Origin and geographic distribution
Endive was probably first brought into cultivation in the eastern Mediterranean, where its wild relative (Cichorium endivia ssp. divaricatum (Schousboe) P.D. Sell) still occurs. Endive (ssp. endivia) was known to the old Egyptians, spread to India at an early date and to Central Europe in the 16th Century. It is now grown throughout the world. In the tropics it is of some importance in the Philippines, Malaysia, Central and West Africa, and the Caribbean.
Endive is most commonly eaten as a fresh green in salads, for which curly-leaved forms are preferred. Plants for salads are often blanched to reduce bitterness. Green plants and broad-leaved forms (escarole) are also used as a cooked vegetable. In Indonesia endive is eaten fresh or steamed as a side-dish with rice. It is sometimes used in making pickles ("asinan") but otherwise not used in a processed form.
Production and international trade
The main area of production is the European Community with 530 000 t per year from 26 000 ha in 1985, followed by North America with about 50 000 t. No statistics are available for other areas.
Endive contains per 100 g edible portion: water 95 g, protein 1.2-2 g, fat 0.2 g, carbohydrates 1-1.5 g, fibre 1 g, K 300 mg, Ca 20-80 mg, P 20-70 mg, Mg 14-20 mg, Fe 0.7-2 mg, vitamin A 1600-3200 IU, vitamin B 0.2 g, vitamin C 5-10 mg, niacin 0.4-0.5 mg. Endive contains inulin and intybin, which cause the typical bitter taste and which supposedly stimulate appetite. The 1000-seed weight is 1.3-1.6 g.
- Annual, sometimes biennial herb containing bitter milky juice, producing a shortened stem with a rosette of large leaves when young.
- Rosette leaves alternate, sessile, thinly pubescent or glabrous, yellow or light to dark green, sometimes reddish along midrib; in escarole types, leaf-blade broadened, 10-25 cm × 8-15 cm, slightly crumpled, margin entire or dentate; in curly-leaved types, leaf-blade reduced, very narrow, deeply pinnatifid and strongly curled; both types form a loose head, usually creamy in the centre.
- In the generative stage, endive produces an erect branched stem, 50-150 cm high, with progressively smaller leaves.
- Inflorescence a terminal or axillary head, 1-3 together, sessile or peduncled, blue-flowered; involucre with outer row of 5 bracts, and inner row of 8 bracts; flowers all ligulate, numerous; stamens 5 with anthers fused.
- Fruit an obovate achene, 2-3.5 mm × 1 mm, with pappus of minute persistent membranous scales.
Growth and development
Flowers usually open in the morning hours only and wither 6 hours later. Most cultivars are self-pollinating, but some cross-pollination caused by insects is normal.
Other botanical information
Up to now it is common practice in taxonomic literature to distinguish two subspecies: ssp. endivia for the cultivated taxa and ssp. divaricatum for the wild taxa. It seems best to classify the cultivated taxa directly in cultivar groups and cultivars. Three groups can be distinguished and are proposed here:
- cv. group Escarole (synonym: C. endivia L. ssp. endivia var. latifolium Lamk): with broad, almost entire, rather flat leaves, forming a loose head; some well-known cultivars are "Batavian Broad-Leaved", "Escarole", "Deep Heart Fringed" and "Growers Giant".
- cv. group Curled Endive (synonym: C. endivia L. ssp. endivia var. crispum Lamk): with narrow, deeply pinnatifid, strongly curled leaves, forming a loose head; some well-known cultivars are: "Salad King", "Green Curled" and "Green Curled Ruffic".
- cv. group Small Endive (synonym: C. endivia L. spp. endivia var. endivia ): with very small leaves which do not form a head; this group is hardly grown anymore.
Endive is an easy to cultivate vegetable. It is more tolerant of high temperatures than lettuce and can be grown from cool temperate areas to tropical lowlands, though in the tropics better results are obtained above 500 m. The mean daily optimum temperature for growth is 15-18 °C. Endive tolerates only light frost. At high temperatures leaves may become fibrous.
Endive requires long days for flowering and rarely flowers in the tropics. Vernalization (at temperatures below 15°C) gives an additional stimulus to flowering and can occur during ripening of the seed, storage of seed and from sowing onwards.
Endive prefers a loose, pervious soil, sufficiently fertile, especially in the top 20 cm, with a pH of 6.5-7.8.
Cultivation of endive is similar to that of lettuce, but generally less demanding. It requires a deeply tilled soil and a friable seed-bed. It is propagated by seed. If sown in a seed-bed, seedlings are transplanted about 1 month after sowing, when they have 4-6 leaves. Direct sowing is practised as well. The planting distance is 25-40 cm × 25-40 cm, with the widest spacings for the broad-leaved cultivars. Dense planting favours self-blanching, but increases the risk of rot.
Nitrogen requirements of endive are moderate, heavy applications leading to strongly increased nitrate contents in the leaves and increased susceptibility to rotting. Phosphate requirements are high, those of potassium moderate, a crop of 12 t removing about 20 kg of P2O5 and 45 kg K2O. Mg deficiency may occur on acidic soils or where ample potassium is available, but can be corrected by spraying a 2% solution of magnesium sulphate.
An irregular supply of moisture may cause discolouration of the edges of younger leaves. Endive does not tolerate waterlogging.
Diseases and pests are rarely serious in endive. Botrytis cinerea, Sclerotinia spp. and various bacteriae may cause "bottom rot" (rot of the base of the plant), Marssonina panattoniana and Alternaria cichorii can cause leaf-spot, Bremia lactucae downy mildew. Aphids, larvae of Noctuidae and various caterpillars may cause damage. Endive should not be planted after pulses, carrots, potatoes, garden beets and other composite crops, because of possible nematode build-up.
Endive matures in 60-90 days from sowing. About a week before harvesting, heads are often tied up in order to blanch them and to moderate the bitterness of the product. Blanching can also be achieved by covering each plant with a pot or container to exclude light (for about 10 days). There are self-blanching cultivars (especially when densely planted). Harvesting can start when heads have reached a marketable size (250-400 g). It is done by cutting the heads from the roots, removing the outer, discoloured or damaged leaves and placing the heads upside down in containers. Yields per ha can reach 20 t of marketable produce per crop.
At ambient temperatures endive can be stored for only 1 day. When cooled to 0-1 °C and at a humidity of 90-95%, healthy heads can be stored for up to 2 weeks.
Genetic resources and breeding
Small collections of germplasm are kept by commercial breeders, at the Institut für Pflanzenbau und Pflanzenzüchtung, Braunschweig, Germany, and at the Vegetable Production Research Unit, USDA, Salinas, California. Very little breeding work is done. Commercial seed production is concentrated in Mediterranean countries.
Endive has a place in western cuisine in the tropics, where it often replaces lettuce in salads. Its relative ease of cultivation, bolt resistance and the availability of self-blanching cultivars favour its continued cultivation.
- Krug, H., 1991. Gemüseproduktion [Vegetable production]. 2nd edition. Verlag Paul Parey, Berlin, Germany. pp. 463-466.
- Nonnecke, I.L., 1989. Vegetable production. Van Nostrand Reinhold, New York, United States. pp. 466-472.
- PAGV, 1987. Teelt van andijvie [Cultivation of endive]. Teelthandleiding 22. Proefstation voor de Akkerbouw en de Groenteteelt in de Vollegrond (PAGV), Lelystad, the Netherlands. 52 pp.
- Tindall, H.D., 1983. Vegetables in the tropics. MacMillan, London, United Kingdom. pp. 82-84.
- L.P.A. Oyen