is produced in Latin America and more than half in Brazil and India. Global
production in 2004 was 1.3 million MT, according to FAO.
PLANTING
Propagation: by seed, normally planted directly into the final growing place.
Soil: should be deep and well drained and without compact layers or hard pans as
castor is intolerant of waterlogging. Moderately susceptible to salinity, the giant
varieties being more tolerant than the dwarf types.
The plant is a heavy feeder, and needs relatively high fertiliser use, typical
applications being, in kg/ha 25–50N, 50–70P and 40–50K. Too much Nitrogen
causes an overproduction of vegetative growth and lower yields of seed.
Seed rate: 10–20 kg/ha. Seed dressing is often used to combat damping off and
insects.
Seed spacing: very variable, but modern varieties normally have 70–100 cm
between rows and 25–30 cm between plants. Dwarf varieties are planted at about
40,000 plants/ha. Often 2–4 seeds are planted at each station and thinned to single
Depth: 3 8 cm
Germination: castor seed is quite delicate and should be handled carefully.
Undamaged seed can remain viable for 2–3 years. It will germinate at a lower soil
temperature than maize, but only slowly, and emergence may take ten days or more.
GROWTH CONDITIONS
Day length: castor is a mainly day-neutral species, with some long-day varieties.
Growth period: the average is 140–180 days for most tall varieties, minimum about
120 days, for dwarf varieties. Basically it is a short lived perennial.
30°C.
Seed set can be reduced above about 40°C.
Rainfall: castor is moderately drought resistant and can grow with only 300–500
mm a year, although it does need more water than maize in the early growth stages.
Perennial varieties need less water than annuals. It does not tolerate heavy rainfall
during flowering, nor waterlogging. It is grown under irrigation in North America.
Altitude: 0–2100 m
Weeds: should be well controlled until the plants are about 80 cm tall, taking care
not to damage the plants root system which is near to the surface.
Rotation: it is often rotated with finger millet (Eleusine coracana). If forage crops
are grown after castor, care should be taken to remove any volunteer castor plants.
The root system improves soil tilth and in this way is beneficial to the crops that
follow castor in the rotation, though the plant does remove large amounts of
nutrients from the soil (See “Soil” above).
Intercropping: commonly grown mixed with legumes, maize, sorghum, cotton,
sesame, groundnuts and cassava.
Pests: a large number of insects attack castor, which is not toxic to them, but
damage is not normally severe. Some varieties have some resistance (tolerance) to
some insects.
per kg.
plants when about 30 cm tall. Seed size varies from about 1000 to 11,000 seeds
GROWING FOOD – THE FOOD PRODUCTION HANDBOOK 191
Temperature: castor is killed by frost. Optimum growing temperature is 20–