Cyamopsis tetragonoloba (L.) Taubert
Family
Leguminosae
Synonyms
Cyamopsis psoraloides (Lamk) DC.
Vernacular Names
|
Malaysia |
Kottavarai (Malayalam, Tamil). |
|
English |
Guar, cluster bean, Siam bean. |
|
Myanmar |
Pe-walee, walee-pe. |
|
Thailand |
Thuakua (central). |
|
French |
Cyamopse it quatre ailes. |
Geographical Distributions
Cyamopsis tetragonoloba is a cultigen of uncertain origin. It has been speculated that C. tetragonoloba originated in north-western India and Pakistan from C. senegalensis Guill. & Perro The latter species, which occurs from Senegal to the Arabian Peninsula, is occasionally used as a fodder and may have been taken by Arabian traders to India as fodder for horses, which was one of their main trading commodities. C. tetragonoloba was taken to Indonesia, Malaysia, and the Philippines around 1915. It is now grown in many parts of the drier tropics and subtropics. Introduced into the United States in 1903, it was developed into an industrial gum-producing crop during the second World War.
Description
Cyamopsis tetragonoloba is a robust, bushy, erect, annual herb, which can grow 20-100 cm tall in improved cultivars and up to 3 m in landraces. The root system is laterally well-developed. The stems and branches are angular, grooved, appressed pubescent with white, forked hairs but sometimes glaucous. Some cultivars remain unbranched.
The leaves are arranged alternate and trifoliolate. The leaflets are elliptical to ovate, with terminal 8-12 cm longand lateral 5-8 cm long. The rachis is 3-7 cm long and cushion-shaped. The margins are toothed where the length of the teeth is less than 1/10 of the breadth of the leaflet that usually exceeds 1 cm.
The inflorescence is a dense and axillary raceme with 5-30 flowers. The flowers are up to 9 mm long. The sepal is hairy, ending in 5 unequal teeth where the carinal tooth is longest. The petals are creamy white on emergence, changing from pink to light purple, and standard orbicular while the wings and keel are oblong. There are 10 stamens. The filaments are united into a staminal tube while anthers are apiculate.
The pod is 6-12-seeded, measures 4-12 cm long, and in stiff erect clusters. It is pubescent or smooth, straight to slightly curved, beaked, with a single ridge at one suture and two ridges at the other. The seed is hard, flinty, flattened, ovoid, measures about 5 mm long, white, grey or black. Seedling is with epigeal germination.
Ecology / Cultivation
Cyamopsis tetragonoloba is a hardy, drought-tolerant legume. It grows in a wide range of environments from the sub-humid to semi-arid conditions in the tropics and subtropics with (300- )500-800( -1500) mm of rainfall. The main production of C. tetragonoloba for seeds occurs where annual rainfall is less than 800 mm. In areas with higher rainfall, vegetative growth is greater, but seed quality is inferior, making guar more suitable as a green manure and fodder crop. Guar prefers a very hot climate. Mean monthly maxima in northern India may reach 35-40°C, though in southern India extremes are lower. Optimum soil temperature for root development is 25-30°C. C. tetragonoloba is cultivated up to 900 m altitude. It is highly susceptible to frost. The optimum temperature for germination is about 30°C. At 20°C, germination is retarded, and at still lower temperatures, the rate of germination is reduced. It can grow in most soils, but thrives in well-drained alluvial and sandy-loam soils of pH 7.0-8.0. Waterlogging is not tolerated. On heavy soils, C. tetragonoloba should be grown on ridges to maintain root aeration. In an experiment using irrigation water with equal amounts of NaCI and CaCI2, salinity levels up to 8.8 dS/m did not affect germination, early growth or grain yields.
Line Drawing / Photograph
References
- Plant Resources of South-East Asia No.11: Auxiliary plants.
