Soil

Castor does well in the soil which is not fit for valuable commercial and food crops. It can be grown on a wide range of soils, provided they are fairly deep and well drained.

The most suitable soils for castor are deep, moderately fertile, with slightly acidic conditions, well drained, sandy loams. While castor prefers deep sandy loam soil with a pH of around 6, it can be cultivated on soils with pH range of 5 - 8.

Land Preparation

For good growth, castor requires a well pulverised seed bed with loose sub-soil upto 45 cm depth. For annual varieties the seedbed must be weed free as young plants are delicate. Good weed control is essential, both pre- and post-emergence.

It does not require fine tilth, but for germination it requires adequate moisture for a longer period in seed bed, preferably to a depth of 15-20 cm.

Sowing

Castor bean is usually planted at the start of the rainy season during the later part of May and early June, or at the end of the rainy season in the late September and early October. Sow in such dates / periods as to avoid wet weather in 2nd half of the crops life.

Castor bean seeds for planting must be healthy, vigorous, hardy and come from prolific mother plants.

After the seedbed has been deeply cultivated, seeds in mechanized countries are planted 4–7.5 cm deep in rows 1 m apart; and about 50 cm apart within rows (some varieties can be planted just 25 cm apart).

For unmechanized societies that prefer larger varieties, seeds are planted 60 by 90 cm apart, 2–4 seeds per hole, and then thinned to one plant.

Fertilizers

The fertilizer dose recommended for castor is 40 N-40 P-20 K kg/ha.

Castor bean needs plenty of nitrogen especially during its early development. A hectare with 1,600 hills requires complete fertilizer (14-14-14) at planting time at the rate of 30 grams per hill.

Unbalanced nitrogen application encourages growth of foliage at the expense of flower and seed formation.