From the Handbook of Energy Crops, unpublished
by James A. Duke
Hibiscus sabdariffa L.
Malvaceae
Roselle
Uses
Folk
Medicine
Chemistry
Description
Germplasm
Distribution
Ecology
Cultivation
Harvesting
Yields
and Economics
Energy
Biotic
Factors
References
Uses
Source of a red beverage known as jamaica in Mexico (said to contain
citric acid and salts, serving as a diuretic). Calyx, called karkade in
Switzerland, a name not too different from the Arabic. Karkade is used
in jams, jellies, sauces, and wines. In the West indies and elsewhere
in the Tropics the fleshy calyces are used fresh for making roselle
wine, jelly, syrup, gelatin, refreshing beverages, pudding, and cakes,
and dried roselle is used for tea, jelly, marmalade, ices, ice-cream,
sherbets, butter, pies, sauces, tarts, and other desserts. Calyces are
used in the West Indies to color and flavor rum. Tender leaves and
stalks are eaten as salad and as a pot-herb and are used for seasoning
curries. Seeds have been used as an aphrodisiac coffee substitute.
Fruits are edible (Watt and Breyer-Brandwijk, 1962). Perry cites one
study showing roselle's usefulness in arteriosclerosis and as an
intestinal antiseptic (Perry, 1980). Roselle is cultivated primarily
for the bast fiber obtained from the stems. The fiber strands, up to
1.5 m long, are used for cordage and as a substitute for jute in the
manufacture of burlap.
Folk Medecine
Reported to be antiseptic, aphrodisiac, astringent, cholagogue,
demulcent, digestive, diuretic, emollient, purgative, refrigerant,
resolvent, sedative, stomachic, and tonic, roselle is a folk remedy for
abscesses, bilious conditions, cancer, cough, debility, dyspepsia,
dysuria, fever, hangover, heart ailments, hypertension, neurosis,
scurvy, and strangury. The drink made by placing, the calyx in water,
is said to be a folk remedy for cancer. Medicinally, leaves are
emollient, and are much used in Guinea as a diuretic, refrigerant, and
sedative; fruits are antiscorbutic; leaves, seeds, and ripe calyces are
diuretic and antiscorbutic; and the succulent calyx, boiled in water,
is used as a drink in bilious attacks; flowers contain gossypetin,
anthocyanin, and glucoside hibiscin, which may have diuretic and
choleretic effects, decreasing the viscosity of the blood, reducing
blood pressure and stimulating intestinal peristalsis. In Burma, the
seed are used for debility, the leaves as emollient. Taiwanese regard
the seed as diuretic, laxative, and tonic. Philippines use the bitter
root as an aperitive and tonic (Perry, 1980). Angolans use the
mucilaginous leaves as an emollient and as a soothing cough remedy.
Central Africans poultice the leaves on abscesses. Alcoholics might
consider one item: simulated ingestion of the plant extract decreased
the rate of absorption of alcohol, lessening the intensity of alcohol
effects in chickens (Watt and Breyer-Brandwijk).
Chemistry
Per
100 g, the fruit contains 49 calories, 84.5% H2O, 1.9 g protein, 0.1 g
fat, 12.3 g total carbohydrate, 2.3 g fiber, 1.2 g ash, 1.72 mg Ca, 57
mg P, 2.9 mg Fe, 300 mg b-carotene equivalent, and 14 mg ascorbic acid.
Per 100 g, the leaf is reported to contain 43 calories, 85.6% H2O, 3.3
g protein,0.3 g fat, 9.2 g total carbohydrate, 1.6 g fiber, 1.6 g ash,
213 mg Ca, 93 mg P, 4.8 mg Fe, 4135 mg b-carotene equivalent, 0.17 mg
thiamine, 0.45 mg riboflavin, 1.2 mg niacin, and 54 mg ascorbic acid.
The inflorescence, per 100 g, is reported to contain 44 calories, 86.2%
H2O, 1.6 g protein,O.l g fat, 11.1 g total carbohydrate, 2.5 g fiber,
1.0 g ash, 160 mg Ca, 60 mg P, 3.8 mg Fe, 285 mg b-carotene equivalent,
0.04 mg thiamine, 0.6 mg riboflavin, 0.5 mg niacin, and 14 mg ascorbic
acid (Duke and Atchley, 1984). Seeds contain 7.6% moisture, 24.0% crude
protein, 22.3% fat, 15.3% fiber, 23.8% N-free extract, 7.0% ash, 0.3%
Ca, 0.6% P, and 0.4% S. Seed extracted with ether contained 0.7% fat,
29.0% protein, and 32.9% N-free extract (Samy, 1980 Zeits Ernahungwiss.
19:47.) Component acids of the seed lipids were 2.1% myristic-, 35.2%
palmitic-, 2.0% palmitoleic-, 3.4% stearic-, 34.0% oleic-, 14.4%
linoleic-, and 3 unusual HBr-reacting fatty acids (cis-12,
13-epoxy-cis-9-octadecenoic (12,13-epoxoleic) 4.5%; sterculic, 2.9%;
and malvalic, 1.3%) Ahmad et al. (J. Sci. Food & Agric. 4: 424.
1979). Salama and Ibrahim (Planta Medica 36: 221. 1979) report on the
sterols in the seed oil, 61.3% b-sitosterol, 16.5% campasterol, 5.1%
cholesterol, and 3.2% ergosterol (said to be rare in vegetable oil but
the most common mycosterol in most fungi, including yeast). Seed has
properties similar to those of cotton seed oil, and is used as a
substitute for crude castor oil. Karkade (dried-flowers minus-ovary)
contains 13% of a mixture of citric and malic acid, two anthocyanins
gossipetin (hydroxyflavone) and hibiscin, and 0.004–0.005% ascorbic
acid. Petals yield the flavonal glucoside hibiscritin, which yields a
crystalline aglycone—hibiscetin (C15H10O9). Flowers contain
phytosterols. The dried flower contains ca 15.3% hibiscic acid
(C6H6O7). Root contains saponins and tartaric acid. Calyces contain
6.7% proteins by fresh weight and 7.9% by dry weight. Aspartic acid is
the most common amino acid. Dried fruits also contain vitamin C and Ca
oxalate; dry petals contain flavonol glucoside hibiscitrin.
Description
Erect,
mostly branched, annual; stem to 3.5 m tall, variously colored dark
green to red; leaves alternate, glabrous, long-petiolate, palmately
divided into 3–7 lobes, with serrate margins; flowers large,
short-peduncled, red to yellow with dark center; capsules 5 cm long,
5.3 cm wide; root a deep penetrating taproot. Fl. summer.
Germplasm
Reported
from the Indochina-Indonesia to African Centers of Diversity, roselle,
or cvs thereof, is reported to tolerate high pH, laterite, low pH,
nematodes, and virus. Several cultivars are known, the best known are:
'Victor', 'Rico' and 'Archer'. Of the botanical varieties: var. sabdariffa, has red or pale yellow inflated edible calyces, but poor fiber; var. altissima Webster is grown for its fiber, but has inedible calyces. (n = 18; 4n = 72, a tetraploid)
Distribution
Native to Old World Tropics, probably in the East Indies; now cultivated throughout the tropics.
Ecology
Suitable
for tropical climates with well-distributed rainfall of 1500–2000 mm
yearly, from sea-level to about 600 m altitude. Tolerates a warmer and
more humid climate than kenaf, but is more susceptible to damage from
frost and fog. Plant exhibits marked photoperiodism, not flowering at
shortening days of 13.5 hours, but flowering at 11 hours. In United
States plants do not flower until short days of late fall or early
winter. Since flowering is not necessary for fiber production, long
light days for 3–4 months is the critical factor. Roselle requires a
permeable soil, a friable sandy loam with humus being preferable;
however, it will adapt to a variety of soils. It is not shade tolerant
and must be kept weed-free. It will tolerate floods, heavy winds or
stagnant water. Ranging from Warm Temperate Moist through Tropical Wet
to Very Dry Forest Life Zones, roselle is reported to tolerate annual
precipitation of 6.4 to 42.9 dm (mean of 213 cases = 17.14) annual
temperature of 12.5 to 27.5°C (mean of 213 cases = 23.11) and pH of 4.5
to 8.0 (mean of 119 cases = 6.1). (Duke, 1978, 1979)
Cultivation
Soil
preparation should be deep, about 20 cm, and thorough. Seed, 11–22
kg/ha depending upon the soil, is drilled about 15 cm by 15 cm at
beginning of rainy season, mid-April in India, planting to a depth of
about 0.5 cm. Broadcasting is not recommended because of uneven stand,
land, and hence lack of uniformity in fiber. When grown for its fiber,
it is planted closely to produce long stems with little foilage.
Weeding for first month is important. Fertilization practices vary
widely. Roselle responds favorably to applications of nitrogen, and 45
kg/ha is a safe level in India, applied in the form of compost or
mineral fertilizer in conjunction with a small quantity of phosphate.
In Java green manure (Mimosa invisa)
is p;owed under before it starts to 5 mature seeds. Also in Java the
following fertilizer rates are recommended for roselle: 80 kg N/ha,
36–54 kg P2O5/ha and 75–100 kg K2O/ha. Rotations are sometimes used,
the roselle, requiring several months to grow, making the land
unavailable for other crops. The practice is recommended since the
root-knot nematode, Heterodera radicicola,
is a pest. A sequence of a legume green-manure crop, then roselle and
then corn is suggested. For home gardens of roselle, seeds are sown
directly in rows about May 15. After germination, seedlings are thinned
to stand 1 m apart. For larger plantings, seeds are sown in protected
seedbeds and the seedlings transplanted to 1.3–2.6 m apart in rows
2–3.3 m apart. Applications of stable manure or commercial fertilizers
are beneficial. Plants are subject to injury by root-knot nematodes and
should not be planted on land infested with these pests.
Harvesting
For
the calyces of fruits, about 3 weeks after tile onset of flowering, the
first fruits are ready for picking. The fruit consists of the large
reddish calyces surrounding the small seed pods. Capsules are easily
separated, but need not be removed before cooking. For fiber, from
planting to harvest is about 3–4 months, 10 months in Indonesia. Fiber
quality is best if harvested just at flowering time. Stems are cut off
at ground level, tied in bundles and retted until the fiber is freed
from the wood. Then it is washed and dried in the sun. A skilled worker
can strip 36–45 kg dry clean fiber daily in this practice. Retting is
by-passed if a decorticating machine is used.
Yields and Economics
Calyx
production ranges from ca 1.5 kg (Calif.) to 2 kg (Puerto Rico) to 7.5
kg/plant in South Floridia. In Hawaii, roselle intercropped with
yielded 16,000 kg/ha, 19,000 kg when planted alone. Dual purpose
plantings can yield 17,000 kg of herbage in 3 cutiings and later
6,300kg of calyces (Morton, 1975). Average fiber production is 1,700
kg/ha with as much as 3,500 kg/ha reported (Malaya). The amount of
fiber in the stalks is about 5%. In Indonesia land rent is for ten
months at rate of 42,000 Rp./ha and 100 workers/ha/month are required.
Field workers are paid 60 Rp/day (July 1971). The FOB export price to
Brussels recently was 106 British pounds per long ton. Indonesians have
no problems selling all the roselle gunny bags they can make.
Energy
As
a multiple-use species, roselle is often mentioned as an energy
candidate, yielding fiber, beverage, edible foliage, and an oil seed.
If it is grown for fiber, much biomass remains as residue. Crane (1949)
calculates that the extracted fiber represents only 1.3–7.9% of the
stalk material, suggesting residues at least 10 times more massive than
the fiber. (It is not clear whether Crane's percentages are based on
dry matter or wet matter.) Crane generalizes that fiber yields run ca
1600 kg/ha with yields in West Africa closer to 650 kg/ha, 2100 kg/ha
in Sri Lanka, 1500 in Java, and experimental yields of 1200 to 3400
kg/ha in Malaya. Residue yields (biomass) should be more than ten times
higher.
Biotic Factors
Roselle is attacked by several fungi: Aecidium
garckeanum, A. hibiscisurattense, Alternaria macrospora, Cercospora
abelmoschi, C. malaysensis, Corynespora cassiicola, Cylindrocladium
scoparium, Diplodia hibiscina, Fusarium decemcellulare, F. sarcochroum,
F. solani, F. vasinfectum, Guignardia hibisci-sabdariffae, Irenopsis
molleriana, Leveillula taurica, Microsphaera euphorbiae, Phoma
sabdariffae, Phymatotrichum omnivorum, Phytophthora parasitica, Ph.
terretris, Pythium perniciosum, Rhizocotonia solani, Sclerotinia
fuckeliana, S. sclerotiorum, Sclerotium rolfsii. Plants attacked
by leaf-spot disease are treated by spray applications of fungicides
for control. Roselle plants are also attacked by several viruses: Leaf
curl, Cotton leaf curl and Yellow vein mosaic. The bacterium, Bacillus solanacearum, has been isolated from roselle. They are very seriously attacked by root-knot nematodes: Meloidogyne arenaria, M. incognita acrita and M. javanica. Among the insect pests which attack roselle are: Anomis erosa, Chaetocnema spp., Cosmophila
erosa, Dysdercus cingulatus, D. poecilus, Drosicha townsendi, Nistora
gemella, Phenacoccus hirsutus, Pseudococcus filamentosus and Tectocoris diophthalmus.
References
Crane, J.C. 1949. Roselle—a potentially important plant fiber. Econ. Bot. 3:89–103.
Duke, J.A. 1978. The quest for tolerant germplasm. p. 1–61. In: ASA
Special Symposium 32, Crop tolerance to suboptimal land conditions. Am.
Soc. Agron. Madison, WI.
Duke, J.A. 1979. Ecosystematic data on economic plants. Quart. J. Crude Drug Res. 17(3–4):91–110.
Duke, J.A. and Atchley, A.A. 1984. Proximate analysis. In: Christie,
B.R. (ed.), The handbook of plant science in agriculture. CRC Press,
Inc., Boca Raton, FL.
Morton, J.F. 1975. Is there a safer tea? Morris Arb. Bul. 26(2):24–30.
Perry, L.M. 1980. Medicinal plants of east and southeast Asia. MIT Press, Cambridge.
Watt, J.M. and Breyer-Brandwijk, M.G. 1962. The medicinal and poisonous
plants of southern and eastern Africa. 2nd ed. E.&S. Livingstone,
Ltd., Edinburgh and London.
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