A third type, Pisum arvense var. abyssinicum, is grown in northern Ethiopia and
Eritrea. It has very sweet seeds, with a black hilum, and very small reddish/purple
flowers.
All three types are entirely self-pollinated. Varieties with edible pods are known
as Mange Touts or Sugar Peas. Many of the more recent varieties are bred to be
leafless or semi-leafless.
Peas are nutritionally valuable, the dried seed containing about 25% protein, 1%
fat, and 57% carbohydrate, as well as 337 calories and 100 (10–200) I.U. Vitamin A
potency per 100 mg edible portion.
There are a very large number of regional types of peas, and a large range of
named varieties, all variously adapted to a wide range of growing conditions. They
are grown in temperate regions throughout the world, and as a cool season crop in
the subtropics and at high altitudes in the tropics.
The major producers of dried field peas are China, Russia, India, America and
Zaire.
PLANTING
Soil: peas tolerate a wide range of soil types, provided they are not waterlogged,
In general, but not always, they give an economic response to fertilisers, though
less than most other legumes. Maximum Nitrogen is c.60 kg/ha—nitrogenous
fertilisers may sometimes even reduce yields. In the UK pea crops receive about
80 kg/ha P and K.
Seed rate: 65–100 kg/ha for smaller seeded varieties, 130–170 kg/ha for larger
fungicide/ insecticide dressings.
Seed spacing: 30–60 cm between rows, 6–18 cm between plants. In trials in India,
the best yields were obtained with 7.5 × 7.5 cm square grids.
Depth: 2.5–6 cm. In light, dry soil they can be planted even deeper.
GROWTH CONDITIONS
Growth period: 90–160 days for dried seed, 56–84 days for green seed or pods,
depending on variety, climatic conditions and planting date.
Temperature: peas are essentially a cool weather crop. For germination, 4C
minimum, 37C maximum. High temperatures stimulate the plant to flower too
early. Frost is tolerated in the vegetative stages, but at flowering can cause heavy
pod loss, and at pod set can cause deformed and discoloured seed.
Rainfall: the optimum is 800–1000 mm per year evenly distributed, with dry
weather at harvest. They can grow with as little as 300 mm per year if the soil is
deep and retentive, as the taproot can reach down more than one metre in search of
water.
best altitude is between 2100 and 2700 m. In Ethiopia the best altitude is between
1500 and 2200 m with rainfall less than 600 mm, and 2200–2300 m with rainfall
more than 600 mm per year.
°
°
seeded ones. 100 seeds weigh about 15–25 g. Seed benefits very much from
5.5 6.5, though some varieties tolerate a pH of 6.9–7.5. –
though in clays and very sandy soil they do not grow well. The optimum pH is
Altitude: in the tropics, about 1200 m is the lowest they will survive. In Kenya the