lathyrism sometimes occurs due to admixture with seed of the common vetch (Vicia
sativa). The toxin is greatly reduced if the seed is soaked in plenty of water for some
hours, then sun-dried, or if the grain is partially boiled in the same way as rice.
Unfortunately this causes the B Vitamins to be lost. The toxin is not destroyed
during the normal methods of preparing chapattis. There is much research work
currently in progress to breed varieties with lower levels of the amino acid.
People who regularly eat vetch (and HIV patients) may appear to be well
nourished but they should be included in food relief and supplementary feeding
programmes since malnutrition, particularly Sulphur amino acid, Zinc and
Manganese malnutrition during famine caused by drought is a key factor leading to
lathyrism. Diets with N-acetyl-cysteine are likely to be beneficial, but a nutritionist
should be consulted for formulation together with other essential nutrients and safe
dosage of this very acidic Sulphur amino acid precursor.
(Source of information: Dr Dirk Enneking,http://barley.ipk-gatersleben.de)
PLANTING
Soil: vetch/grass pea adapts to a wide range, including poor, infertile soils and heavy
clays. The plants tolerate waterlogging better than other food legumes but they do
not grow well in acidic soils. Fertiliser is not normally applied to the crop.
Intercropping: very common, for example with rice, barley, linseed and chickpeas.
Seed spacing: normally broadcast. When drilled, 2.5 cm between plants, 30–50 cm
between rows.
Seed rate: 45–55 kg/ha pure stand, 20–40 kg/ha when intercropped.
Inoculation: not normally necessary, nor worthwhile.
GROWTH CONDITIONS
Growth period: 120–180 days. The plants are either cut with a sickle or uprooted,
and then dried, as soon as the pods turn yellow - delayed harvest leads to a big seed
loss from shattering.
Temperature: the optimum is 10–25°C—in India, for example, it is considered to
be a “cold weather crop”.
Rainfall: very drought resistant. 380–650 mm a year is usually enough, though it
also tolerates heavy rainfall.
Altitude: in India vetch/grass pea is grown from sea level up to about 1200 m.
Pests: not normally a problem. Red-legged mites and aphids sometimes cause some
damage.
Diseases: in India, mildews, rust and wilt are reported to cause some damage. Some
wilt resistant varieties are available.
YIELD
The average seed yield of the grass pea in India is about 250–450 kg/ha.
In a pure stand, and in good conditions and with efficient cultivation it can yield
one MT/ha or more.
Yields of forage (hay ) in a pure stand also average just over one MT/ha.