Lathyrus sativus (PROSEA)
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Introduction |
- Protologue: Sp. Pl.: 730 (1753).
- Family: Leguminosae
- Chromosome number: 2n= 14
Vernacular names
- Grass pea (En)
- gesse blanche (Fr)
- Burma: pèsali.
Origin and geographic distribution
Native to Southern Europe and Western Asia. Widely grown in India, Iran, Middle East, parts of Africa and S. America. Most important in India.
Uses
In India seeds are eaten in times of food shortages (white seeds preferred). The seeds may be boiled and eaten as a pulse, split and used as dhal, or ground into a flour and made into unleavened bread, paste balls or curries. Young leaves and fruits are also eaten as a vegetable.
It is also cultivated as a forage crop and for green manure. As fodder the plants can be fed green or as hay, they are not suited for silage.
Oil from the seeds is medicinally used as a powerful cathartic.
Production and international trade
In India about 1.6 million ha is cultivated with grass pea, producing 0.5 million t seeds/year. The crop is consumed locally and does not enter international trade.
Properties
Per 100 g edible portion, seeds contain: water 10 g, protein 25 g, fat 1 g, carbohydrates 61 g, fibre 1.5 g, ash 3 g. The energetic value averages 1231 kJ/100 g. The composition of hay is: water 14.6%, protein 9.9%, fat 1.9%, fibre 36.5%, N-free extract 31.0%, ash 6.1%. Seed weight varies between 5 and 7 g/100 seeds.
People and livestock consuming grass pea as the principle article of diet during months, develop a paralythic disease known as lathyrism. Seeds soaked in water for 24 h before cooking are not toxic. The poison takes effect in various parts of the central nervous system, with a great impairing of muscular activity, especially in the lower limbs.
Botany
- A much-branched, suberect, straggling or climbing annual, with winged quadrangular stems up to 90 cm long.
- Leaves 2- or 4-foliolate; leaflets narrowly elliptic-oblong, 3-6.5 mm × 3-11 mm.
- Flowers reddish- purple, pink, blue or white.
- Pods oblong, up to 4 cm long, upper margin 2- winged.
- Seeds wedge-shaped, 4-7 mm in diam., grey to brown, marbled or light green.
- Germination hypogeal.
Plants are self-fertile. Classification is based on colour of flowers, markings on pods and size and colour of seeds.
Ecology
Grasspea is grown as a cold season crop in India. It thrives in areas with average temperature ranges between 10-25°C. It is very drought resistant and is grown successfully with average annual rainfall of 380- 650 mm. It tolerates waterlogging and poor soils. In India grown up to 1200 m altitude.
Agronomy
Grasspea is propagated by seed. Seeds are sown broadcast or in furrows ca. 3 cm apart. In a well-prepared field, the crop comes up as a thick clove mass over the entire surface and smothers out weed. Frequently the crop receives virtually no attention after sowing.
Plants are sole cropped or intercropped (e.g. with rice in India). Seed rate is about 45-60 kg/ha for sole crop, 34 kg/ha when intercropped. No serious diseases or pests exist. Ripe seeds can be harvested 4-6 months after sowing. Average yield of seed is 1000-1500 kg/ha.
Genetic resources
Primitive forms of L. sativus can be found in and around N.W. India. In the Mediterranean forms with large and bright-coloured seeds are present. L. cicera L. from the Mediterranean and W. Asia is a close relative. To solve the problem of lathyrism, low-toxin cultivars are needed.
Prospects
Grass pea will remain important as a crop for extremely dry and poor soils and as a rescue crop when other crops have failed. In S.-E. Asia it is possibly interesting for the very dry areas. More research is needed on effective methods of detoxifying the seeds at the rural level, without reducing their nutritive value.
Literature
- Duke, J.A., 1981. Handbook of Legumes of world economic importance. Plenum Press, New York and London. p. 107-110.
- Kay, D.E., 1979. Crop and product digest No. 3 - Food Legumes. Tropical Products Institute, London. p. 115-123.
Authors
- P.C.M. Jansen
