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Ricinus communis

Authority	L.
Family	Magnoliopsida:Dilleniidae:Euphorbiales:Euphorbiaceae
Synonyms
Common names	bele ni vavalagi, castor bean, castor oil plant, gullo, kasterolieboom, kobo (Galinya), lama papalagi
Editor
Ecocrop code	1866

Notes
DESCRIPTION: Castor in tropical countries is an erect herbaceous shrub or a small plant 6-10 m tall; its longevity is 8-12 years. In moderate climates this plant has a woody stem 0.5-4 m tall and it dies during autumn due to frosts or as a result of desiccation. The taproot penetrates the soil up to 1.5-3 m, or in the case of a crop of many years standing, up to 5-6 m. Most important are the secondary lateral roots that spread in the ploughed layer up to 1 m. If there is insufficient moisture the root grows deep, with little lateral spreading, whereupon their development leads to growth of the above ground mass. The stems are succulent, herbaceous, very variable in all aspects - 7.5-15 cm in diameter. Its stem is geniculate, thick, branching and terminates with a raceme spike. In some of the varieties grown in Russia, the stem has from 5 to 12 nodes and the same number of leaves at a 30-100 cm height of stem, and the length of the internode is 6-10 cm. The dwarf varieties have short (1.5-3 cm) internodes. The castor plant is well foliated. Leaves are glabrous and alternate on the basis of a 2/5 layout, except the first two opposite leaves. They are 10-16 cm wide, smooth, rarely wrinkled and have stipules at the base of their long (20-50 cm) glandular petioles. They are palmate - parted in 7-9 lanceolate dentate lobes - the middle one being the largest. It has monoecious flowers - male and female flowers are on the same plant and form clusters (racemes) 10-40 cm long in terminal pannicles. The tubular perianth is 5-lobed. They are numerous in long inflorescences, petals absent in both sexes (male and female flowers are apetalous), sepals 3-5, greenish; stamens numerous, 5-10 mm long; ovary superior, 3-celled with a short style and 3-6 stigmas. The upper fruit syncarp is a spherical or elongated dehiscent, fragile 3-sectioned dry capsule 2.5 cm in diameter, 1-3.5 cm long with a wrinkled or smooth surface. It is borne on an elongated pedicel, and is often spiny. The colour of the ripening capsules is green, yellow, brown, red, crimson or violet; dried ones are often grey or brown. The seed of castor is nut-oval, tick-like, egg-shaped, rarely spherical or elongated in form, 0.8-3 cm long, 0.6-1.5 cm wide and 0.4-1.0 cm thick. It is carunculate. The seeds are covered by a dense, shiny but fragile hull of two colours. The background is dark, usually dark-gray, red or brown, rarely black or white; there are mosaic spots of various dimensions and colors; pink, white-brown, red, black. The pattern varying from fine to coarse, veined or finely dotted to large splotches. The integument and cotyledons are flat and slender. There are 1,000 to 11,000 seeds per kg; commercial varieties having 2,200 to 3,200 per kg. It is a C3 pathway plant but with restricted assimilation of CO₂. USES: The seeds yield a water-resistant fast-drying, non-yellowing oil, used mainly in industry and medicines. The oil is included in fuel mixtures for precision engines. Dehydrated oil is an excellent drying agent that compares favourably with tung oil and is used in paints and varnishes and as a basic ingredient in emollient soaps. It is used in coating fabrics and other protective coverings, in the manufacture of high-grade lubricants, transparent typewriter and printing inks, in textile dyeing (when converted into sulphonated castor oil or turkey-red oil, for dyeing cotton fabrics with alizarine) and in leather preservation. It is also used for plastics, ointments, and cosmetics. The seed has purgative and emollient properties and administration is as oil, capsules, enema, ointment and suppositories. Pharmacological compounds to combat hair-loss usually contain castor oil and it has an antidandruff effect. The expressed oil cakes are used as fertilizer and detoxified meal can be fed to livestock; although it is highly toxic due to its ricin (that has been used as a poison), a method of detoxicating the meal has now been found, so that it can safely be fed to livestock. Plant stems are made into paper and wallboard. NB.: The seeds must never be swallowed: 5-6 will kill a child, 10 will kill an adult - there is no specific antidote. KILLING T.: During the rest period it is -2^oC. It does not tolerate low temperatures during the growing period. GROWING PERIOD: Grown as an annual in temperate regions, and as a short-lived perennial under subtropical and tropical conditions. Growing period is 140-160 days for early cultivars, and 170-210 days for late cultivars. COMMON NAMES: Castor, Castorbean, Ricin, Ricino. FURTHER INF.: The name Ricinus is a Latin word for tick; the seed is so named because it has markings and a bump at the end, that resemble certain ticks. Castor perform best with a relative humidity of 30-60 %, ideally humidity should be higher during vegetative growth and lower during the period of maturity and harvest. To high humidity can lead to increased insect problems. Castor can be cultivated between 40°S and 52°N and it can be grown from sea-level up to 1500-3000 m in elevation, but it is best grown between 300-1800 m. The photosynthesis pathway C3 II. The species is most probably indigenous to North-East Africa, especially Ethiopia. 1 ton of seed remove about 30 kg N, 5 kg P, 12 kg K, and 4 kg Ca, and 3 kg Mg from the field. Unbalanced N-fertilizer encourages the growth of foliage at the expense of seed formation. The global average yield is 0.75 t/ha, in Africa 0.5 t/ha but in the United States 3.0 t/ha are not exceptional under irrigation. The seeds of the plant are poisonous, eating a single seed may cause serious illness and the leaves should not be used as forage.
Sources
Plants For A Future Handbook of Energy Crops - J. Duke NewCROP Wikipedia Castor bean Sims D (pers. comm.) Weiss E 1983 pp 31-99 [USE, RAIN, SAL, LIMIT, TEMP, KTMP, PHO, LIG, TEXT, DRA, PH] Roecklein J 1987 pp 338 [USE, TEMP, KTMP] Eswaran H 1986 pp 50 72 83 Rehm S 1991 pp 108-110 [TEMP, RAIN, DRA, DEP, PHO, TEXT, PH, SAL] Kernick M 1961 pp 366 Williams C 1979a pp 178 [RAIN, FER, DRA] Nair P 1980 pp 155-159 [RAIN, TEMP, TEXT, FER, DRA, USE] Onwueme I 1991 pp 359-362 [KTMP, RAIN, DRA, TEMP, FER, DRA, TEXT] Janick J 1991 pp 380 Arens P (pers. comm) Iwu M 1993 pp 232 [USE]