CASTOR (Ricinus communis L.)
Climatic requirements
In the tropics, castor can be grown from sea level to altitudes of about 1000 m. It requires a hot, dry climate with annual rainfall of 500-900 mm, of which 500-¬600 mm is needed during the first 3 months of crop growth. Castor is, therefore, an ideal crop for marginal lands of the Dry Zone where it can be grown under both rain fed and irrigated conditions. High humidity has an adverse effect on castor and when exposed to temperatures above 40°C for a continuous period seeds may not develop.
Castor grows best on medium textured, deep, and well¬ drained fertile soils, but can also be grown on most soils with good physical structure. It cannot tolerate water logging or soil alkalinity.

Land preparation
The land should be ploughed to a depth of 15 cm.
Recommended variety
Hazeera No.1 (oil content 69%). This variety grows to a height of 2-3.5 m depending on soil type, rainfall, and plant density. It is drought tolerant, high yielding, large seeded and non-shattering.
Mixed-cropping system
The following crop varieties to be intercropped with castor should be planted with the first Maha rain:
a) Groundnut - MI-l Red Spanish (100-110 days) No. 45 x -14
b) Blackgram - MI-1 (90 days)
c) Soyabean - PB-l (82-85 days)
Bossier (90-95 days)
d) Greengram - MI-5 (65 days)
Seed rate: 3-5 kg/ha
Time of planting
Planting should be done with the onset of Maha rains in late September or early October.
Planting and spacing
a) Spacing between hills: 180 x 180 cm
b) The soil is heaped and 2-3 seeds are dibbled for each hill. Two weeks after planting, seedlings are thinned to l/hill and any vacant hills replanted.
Fertilizer use: N-51 kg/ha, P2O5-54 kg/ha, K2O-36 kg/ha
a) Basal - apply the following formulations and rates:
i) Urea - 50 kg/ha
ii) TSP -120 kg/ha
iii) Muriate of potash - 60 kg/ha
b) Top dressing - apply 60 kg/ha of urea 4 weeks after planting
Weed control
Castor should be kept free of weeds for 3-4 months after planting, which usually requires five weedings.
Insect control:
The major pests, leaf-eating caterpillars (Achea janata) and capsule borers (Spodoptera litura), are controlled with 60 ml Lanate 18 EC spray in 20 l of water.
Disease control:
Capsule mould is controlled by spraying Captan at 1 oz in 1 gal of water (100 gal of the mixture/ha).
Yields range from 1000 to 1500 kg/ha depending on management practices. The first pick of brown pods (before splitting occurs) are ready 5 1/2 - 6 months after planting.
Harvested pods are dried in the sun for about 1 week, after which seeds are separated with a stick.