Cichorium endivia (PROTA)

Plant Resources of Tropical Africa Introduction

List of species

General importance
Geographic coverage Africa
Geographic coverage World
Vegetable
Food security

1, plant habit; 2, leaf of endive; 3, leaf of escarole. Source: PROSEA

top view of plant habit

flowering plant

flowering top of plant

Cichorium endivia L.

Protologue: Sp. pl. 2: 813 (1753).

Family: Asteraceae (Compositae)

Chromosome number: 2n = 18

Vernacular names

– Broad-leaved types:

• Escarole, broad-leaved endive (En).
• Scarole, chicorée scarole (Fr).
• Chicória escarola (Po).

– Narrow-leaved types:

• Endive, curly endive (En).
• Frisée, chicorée frisée (Fr).
• Chicória frisada (Po).

Origin and geographic distribution

Cichorium endivia is only known from cultivation. It was probably first brought into cultivation in the Mediterranean region, where its wild relatives Cichorium pumilum Jacq. and Cichorium calvum Sch.Bip. ex Asch. occur. Both species can be considered as the progenitor of escarole and endive. Cichorium endivia was probably known to the old Egyptians, but no archaeological evidence has been found. It spread to central Europe in the 16^th century and is now grown throughout Europe and North America. It is grown throughout the tropics including tropical Africa, but is mostly of minor importance there.

Uses

Endive is most commonly eaten as a fresh green in salads, for which curly-leaved types are often preferred. Plants for salads are sometimes blanched to reduce bitterness. Endive is used as a substitute for lettuce in the tropics as it is more resistant to diseases. Broad-leaved types (escarole) are also used as a cooked vegetable. Cichorium endivia is sometimes used in making pickles, but is otherwise not used in a processed form.

Production and international trade

The main area of production is the European Union where 530,000 t was produced from 26,000 ha in 1985, followed by North America with about 50,000 t. No statistics are available for other areas.

Properties

The nutritional composition of escarole per 100 g edible portion is: water 94 g, energy 71 kJ (17 kcal), protein 1.3 g, fat 0.2 g, carbohydrate 3.4 g, fibre 3.1 g, Ca 52 mg, Mg 15 mg, P 28 mg, Fe 0.8 mg, Zn 0.8 mg, vitamin A 2167 IU, thiamin 0.08 mg, riboflavin 0.08 mg, niacin 0.4 mg, folate 142 μg, ascorbic acid 6.5 mg (USDA, 2002). The nutritional composition of endive is about the same, except for the ascorbic acid content, which is 13 mg per 100 g.

Cichorium endivia contains inulin and intybin, which cause the typically bitter taste and which are said to stimulate appetite. More than 100 volatile compounds have been identified; among them hexenal, (E)-2-hexenal and β-ionone, contributing intense odour notes.

Description

• Annual or biennial, erect herb up to 170 cm tall, with taproot containing bitter milky juice, producing a rosette of large leaves when young, these forming a loose head.
• Leaves alternate, simple or pinnatifid, sessile, broad, up to 45 cm × 18 cm, slightly crumpled, margin entire or dentate (escarole type) or very narrow, deeply pinnatifid and strongly curled (curly-leaved type), progressively smaller upwards on stem, slightly pubescent or glabrous, pale to dark green or yellowish, sometimes reddish along midrib.
• Inflorescence a head, 1–6 together, sessile or on up to 20 cm long, apically thickened peduncle; involucre with outer row of 5 bracts 7–10 mm × 2–5 mm, and inner row of 8 bracts 8–12 mm × 1–3 mm.
• Flowers 15–20 per head, all ligulate; corolla up to 2 cm long, blue, sometimes white, 5-lobed at apex; stamens 5 with anthers fused into a tube; ovary inferior, 1-celled, style slender, hairy, with 2 slender stigmatic lobes.
• Fruit an obovoid to cylindrical achene 2–3 mm × 1–1.5 mm, brown, with pappus of 1–3 rows of small, persistent membranous scales.

Other botanical information

Cichorium comprises 6 species and occurs naturally in Europe, northern Africa, and western and central Asia. Two species are commonly cultivated (also in tropical Africa): Cichorium endivia, which is not known from the wild, and Cichorium intybus L. (chicory), which is grown for its roots used as a coffee surrogate, forage and as a source of inulin (fat replacer), and as a leafy vegetable (witloof and radicchio) popular in Europe. These two species are often confused as they are morphologically very similar, but they differ in life span and reproductive system (Cichorium intybus is a self-incompatible perennial), whereas DNA-based analytical methods did not support a close relation.

Three cultivar-groups are distinguished within Cichorium endivia:

– Batavian Group (has also been called Escarole Group, Scarole Group or var. latifolium Lam.): with broad, almost entire, rather flat leaves, forming a loose head; some well-known cultivars are ‘Batavian Broad-Leaved’, ‘Escarole’, ‘Deep Heart Fringed’, ‘Growers Giant’ and ‘Géante maraîchère’.

– Curled-leaved Group (has also been called Curled Endive Group, Frisée Group or var. crispum Lam.): with narrow, deeply pinnatifid, strongly curled leaves, forming a loose head; some well-known cultivars are ‘Salad King’, ‘Green Curled’, ‘Frisée de Ruffec’ and ‘Grosse Pancalière’.

– Cutting Group (has also been called Small Endive Group, Endivia Group or var. endivia): with very small leaves that do not form a head; cultivars belonging to this group are hardly grown anymore.

Growth and development

Cichorium endivia forms a dense rosette of leaves in the first year. Upon bolting the stem elongates and branches. The inflorescence bears many heads. Flowers are usually open in the morning only and wither after about 6 hours. Most cultivars are self-pollinating but some cross-pollination by insects may occur.

Ecology

Escarole and endive are easy to cultivate. They are 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 altitude. The mean daily optimum temperature for growth is 15–18°C. Mild frost is tolerated. At high temperatures leaves may become fibrous. Cichorium endivia requires long days for flowering and rarely flowers in the tropics. Vernalization (in some cultivars at temperatures below 15°C) gives an additional stimulus to flowering and can occur already during ripening of the seed, but also during storage of seed and from sowing onwards.

Escarole and endive prefer a loose, pervious soil, sufficiently fertile, especially in the top 20 cm, with a pH of 6.5–7.8.

Propagation and planting

Cultivation of escarole and endive is similar to that of lettuce, but generally less demanding. They require a deeply tilled soil and a friable seed-bed. They are propagated by seed. If sown in a nursery, seedlings are transplanted about 1 month after sowing, when they have 4–6 leaves. Direct sowing is practised as well. The 1000-seed weight is 1.3–1.6 g; about 0.5 kg/ha of seed is required. The planting distance is 25–40 cm × 25–40 cm, with the widest spacings for broad-leaved cultivars. Dense planting favours self-blanching, but increases the risk of rot.

Management

Nitrogen requirements 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 8 kg of P and 40 kg K. 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 discoloration of the edges of younger leaves. The plants do not tolerate waterlogging.

Diseases and pests

Diseases and pests are rarely serious. Botrytis cinerea, Sclerotinia spp. and various bacteria may cause ‘bottom rot’ (rot of the base of the plant), Marssonina panattoniana and Alternaria cichorii can cause leaf-spot, Bremia lactucae downy mildew. Escarole and endive are resistant to Cercospora longissima, which affects lettuce. Turnip mosaic virus (TuMV) and Endive necrotic mosaic virus (ENMV) may cause mosaic, yellowing and necrosis. Aphids and various caterpillars may also cause damage. Escarole and endive should not be planted after pulses, carrots, potatoes, garden beets and other composite crops, because of possible nematode build-up.

Harvesting

Escarole and endive mature in 60–100 days from sowing. About a week before harvesting, heads may be tied up in order to blanch them and to moderate their bitterness. 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.

Yield

Yields of 20 t/ha of marketable produce per crop can be attained.

Handling after harvest

At ambient temperatures escarole and 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. When grown in the tropics, they are often very bitter; this bitterness can be reduced by packing individual heads fairly tightly in plastic foil and storing them for 4–5 days in a refrigerator at 7°C.

Genetic resources

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 CA, United States.

Breeding

Little breeding work has been done. Commercial seed production is concentrated in Mediterranean countries.

Prospects

Endive and less commonly escarole have a place in Western cuisine in the tropics, where they often complement or replace lettuce in salads. Their relative ease of cultivation, resistance to bolting and the availability of self-blanching cultivars favour their continued cultivation.

Major references

• Krug, H., Berg, E., Crüger, G. & Fölster, E., 1991. Gemüseproduktion: ein Lehr- und Nachschlagewerk für Studium und Praxis. 2nd edition. Verlag Paul Parey, Berlin, Germany. 541 pp.

• Martin, F.W. & Ruberté, R.M., 1975. Edible leaves of the tropics. Agency for International Development Department of State, and the Agricultural Research Service, U.S. Department of Agriculture, United States. 235 pp.

• Messiaen, C.-M., 1989. Le potager tropical. 2nd Edition. Presses Universitaires de France, Paris, France. 580 pp.

• Nonnecke, I.L., 1989. Vegetable production. Van Nostrand Reinhold, New York, United States. 657 pp.

• Oyen, L.P.A., 1993. Cichorium endivia L. In: Siemonsma, J.S. & Kasem Piluek (Editors). Plant Resources of South-East Asia No 8. Vegetables. Pudoc Scientific Publishers, Wageningen, Netherlands. pp. 142–144.

• Rubatzky, V.E. & Yamaguchi, M., 1997. World vegetables: principles, production and nutritive values. 2nd Edition. Chapman & Hall, New York, United States. 843 pp.

• Ryder, E.J., 1999. Lettuce, endive and chicory. Crop Production Science in Horticulture Series. CABI Publishing, Cambridge, United Kingdom. 208 pp.

• Tindall, H.D., 1983. Vegetables in the tropics. Macmillan Press, London, United Kingdom. 533 pp.

• USDA, 2002. USDA nutrient database for standard reference, release 15. [Internet] U.S. Department of Agriculture, Beltsville Human Nutrition Research Center, Beltsville Md, United States. http://www.nal.usda.gov/fnic/foodcomp. June 2003.

Other references

• Kiers, A.M., 2000. Endive, chicory, and their wild relatives: a systematic and phylogenetic study of Cichorium (Asteraceae). Gorteria Suppl. 5. 77 pp.

• FCDB, 2002. Danish food composition database. Revision 5. [Internet] Institute of Food Safety and Nutrition, Ministry of Nutrition, Fisheries and Agriculture, Søborg, Denmark. http://www.foodcomp.dk/fcdb_alphlist.asp. November 2003.

• Takeoka, G., 1999. Flavor chemistry of vegetables. In: Terenashi, R., Wick, E.L. & Hornstein, I. (Editors). Flavor Chemistry. Thirty years of progress. Kluwer Academic, New York, United States. pp. 287–304.

Sources of illustration

• Oyen, L.P.A., 1993. Cichorium endivia L. In: Siemonsma, J.S. & Kasem Piluek (Editors). Plant Resources of South-East Asia No 8. Vegetables. Pudoc Scientific Publishers, Wageningen, Netherlands. pp. 142–144.

Author(s)

• L.P.A. Oyen, PROTA Network Office Europe, Wageningen University, P.O. Box 341, 6700 AH Wageningen, Netherlands

Correct citation of this article

Oyen, L.P.A., 2004. Cichorium endivia L. [Internet] Record from PROTA4U. Grubben, G.J.H. & Denton, O.A. (Editors). PROTA (Plant Resources of Tropical Africa / Ressources végétales de l’Afrique tropicale), Wageningen, Netherlands.

Accessed 12 December 2024.