Common Name: Chickling Pea

General Information

Lathyrus sativus is a much-branched, annual plant growing from a long but thin, well-developed taproot; it can grow 30 - 50cm tall, occasionally to 170cm. The suberect stems often scramble into the surrounding vegetation, supporting themselves by means of tendrils[, , ].
The plant is occasionally cultivated for its edible seed and as a green manure, and was one of the earliest cultivated food crops in Europe with a history of cultivation dating back perhaps 8,000 years. A minor crop nowadays, though it is still popular in some areas, especially on the Indian subcontinent, in the Middle East and north Africa, but also to a lesser extent in America, Australia and South Africa.

Known Hazards

The seed contains a toxic amino-acid known as ODAP which, in large quantities, can cause a very serious disease of the nervous system known as 'lathyrism'. ODAP is present in all parts of the plant and affects various parts of the central nervous system, disrupting neurotransmission and thus impairing muscular activity. The onset of lathyrism can be slow or sudden, and is often indicated by a
feeling of heaviness and pain in the lower limbs. Lathyrism is often irreversible, but not fatal. Lathyrism seems to occur when food ratios containing at least 25% chickling pea are consumed continuously over 6 - 26 weeks and may then affect up to 5% of the population[]. The seed is said to be perfectly safe and very nutritious in small quantities, but should not comprise more than 30% of the diet[, ].
In general, soaking and boiling reduce ODAP levels in the seeds, and this effect is enhanced if water is changed after soaking and during cooking. When the seeds are ground into flour, which is then used in baking or cooking, ODAP may not be removed. Unfortunately, effective detoxification treatments often also result in decrease of nutritional quality[].

Botanical References

, ,

Range

The original habitat is obscure, possibly S. Europe

Habitat

Found as a weed of cultivated land though this is as a relict of cultivation, the plant is not known in a truly wild state[].

Properties

Edibility Rating
Medicinal Rating
Habit	Annual
Height	0.60 m
Pollinators	Insects
Self-fertile	Yes
Cultivation Status	Cultivated, Wild

Cultivation Details

Chickling pea is a plant of temperate to subtropical regions, though it can also be cultivated in the tropics, especially at higher elevations (in Ethiopia it is grown at elevations up to 2,700 metres). It can be grown successfully in regions with a mean rainfall of 400 - 650mm, and a mean temperature of 10 - 25°c during the growing period. It withstands heavy rains in early growth stages and prolonged drought during grain-filling. It grows well in the subtropics as a winter crop[].
An easily grown plant, it does best in a sunny position but can be grown on a wide range of soil types, including poor soils and heavy clays[, ]. It tolerates waterlogging and moderate salinity[].
Flowering time is 6 - 17 weeks after sowing[].
In order to avoid shattering the seedpods and scattering the seed, harvesting of the seeds should be carried out when the leaves turn yellow and pods turn grey. The plants are pulled out by hand or cut with a sickle near the base. They are then stacked and allowed to dry for 7 - 8 days in the field or on the threshing floor[].
The average seed yield is 350 - 700 kilos per hectare; in Ethiopia it is about 700 kg/ha. Yield trials conducted recently in various countries recorded yield levels of 1,500 - 3,000 kg/ha[].
This species has a symbiotic relationship with certain soil bacteria, these bacteria form nodules on the roots and fix atmospheric nitrogen. Some of this nitrogen is utilized by the growing plant but some can also be used by other plants growing nearby[]. When removing plant remains at the end of the growing season, it is best to only remove the aerial parts of the plant, leaving the roots in the ground to decay and release their nitrogen.

Edible Uses

The immature seed can be eaten like green peas[, , ].
The mature seed is eaten cooked[, , , ]. It needs to be soaked and well cooked before being eaten[]. The seed can be eaten in a wide variety of ways: the seeds are often simply boiled and eaten in many areas; they are split and then made into a sauce and eaten with unleavened bread in Ethiopia; they are made into dahl and rotis in India; they can also be ground into a powder then mixed with wheat in a ratio of one part chickling pea to three parts of wheat flour to make a protein-enhanced bread[, ]. Some caution is advised, see the notes above on toxicity.

Young seedpods - cooked and eaten as a vegetable[, , , ]. They can be boiled, salted and consumed as a snack[].

Young shoots - cooked[, ].

Medicinal

The oil from the seeds is a powerful and dangerous cathartic[].

Agroforestry Uses:

The flowers are a good source of nectar for the bees[].
The plant has an extensive root system and fixes atmospheric nitrogen through bacteria that live on the roots. It makes a good soil-enriching green manure crop or can be planted for erosion control[].
Grass pea is grown as a sole crop or intercropped with plants such as barley, linseed or chickpea. In many countries it is produced in rice-based cropping systems before the rice crop or alternately with a rice crop. In India it is often grown as a relay crop: it is broadcast into a standing rice crop about 2 weeks before the rice harvest and left to grow on the residual moisture[].

Other Uses

None known

Propagation

Pre-soak the seed for 24 hours in warm water and then sow in early spring in a cold frame[]. When they are large enough to handle, prick the seedlings out into individual pots and plant them out in the summer.
If you have sufficient seed, then it can also be sown in situ in mid spring[].