• Varied opinions are held regarding the exact land of origin of the castor plant. Some workers view that though castor is cultivated throughout India, Yet it is indigenous to Africa.
• Castor is native to India by some workers.
• They hold this view mainly on the basis of knowledge of the medicinal uses of this plant as found in Sanskrit literature.
• Some workers toured to India and found some evidence only at the foot of Himalayas to show that castor is a native of India.
• They therefore believes that it may have originated in India as well as in Africa.
• Hindus have known castor oil from very remote periods.
• This oil has been mentioned in Susruta Ayurveda, one of the oldest works on Ayurveda.
• It is therefore possible that castor has originated both in India and Africa.

• The world area and production statistics for castor seed are fluctuating every year.
• The main castor seed producing countries are Brazil, India and Argentina.
• Other countries growing castor include Indonesia,Indo-China, Madagascar, Angola and Mozambique.
• During the Second World War the crop was also developed in Mexico and Japan.

• This is by far the most important area now for castor production in India.
• It is sown in July-August and harvested from January to March.
• The crop is concentrated mainly in Mahaboobnagar and Nalgonda districts.
  In the Telangana, castor is sown as a pure crop.
  Mixtures are rare.
  
• Here it is mostly raised as a pure crop but mixtures of castor with Jowar, bajra, groundnut and ragi, are also to be found.

• The production of castor seed in this state is mainly concentrated on the banks of rivers particularly the Ganges.
• Of the total estimated production, about 40 per cent is contributed by Bhagalpur district, 14 per cent by Purnea and Monghyr, 30 per cent by the western districts of Suran, Champaran and Muzaffarpur.
• The balance is drawn from the districts of Darbhanga, Patna and Gaya.
• In the eastern districts, a pure crop is in vogue more than mixtures.
• The crop is sown in September-October and harvested in March - April.
• In the western districts, mixtures are more common and raised both in the kharif (monsoon) and rabi (winter) seasons.
• In Kharif, castor is mixed with maize, Red gram or cotton and in rabi with mustard, peas potatoes or chillies.

• Of the total production, nearly 70 per cent comes from Kathiawar and Gujarat.
• Castor crop is important in Junagadh, Nawanagar, Kutch, Ahmedabad, Surat, East Khandesh and Kaira.
• In the other areas, castor crop is mostly raised as a pure crop.
• If sown as mixtures, it is mixed with cotton, jowar, bajra and sesamum.
• Sowings are done in June-July and harvesting in December to February.

• Salem is an important districts for castor and to a smaller extent Coimbatore, Tiruchirapally and North Arcot districts as well.
• About one-third of this is grown as pure, while the rest is sown as mixture with Sorghum, bajra and groundnut, ragi, etc., Castor is also sown along the borders of sugarcane fields as well as a shade crop for turmeric fields and chillies.

• Of the total production, 20 per cent is drawn from northern district of Lakhimpur, 6 per cent from sitapur and Bahraich, 30 per cent from the central districts of Etawah, Kanpur, Fathepur and allahabad.
• The major portion of the balance is produced in the southern districts of Jalaun, Banda and Hamirpur.
• About 95 per cent of the crop is raised as Kharif which is sown in June-July and harvested between February and April.
• As a mixture, it is raised with maize, arhar, jowar, bajra and cotton.

• The crop is mostly concentrated in the Chitradurg, Tumkur, Mysore and Bangalore districts which, together, cover more than 80 per cent of the total area under castor in the state.
• The crop is generally sown as a mixture with jowar, ragi, lablab etc.
• In some parts of Bangalore district, sowing is done in July and crop harvested from January to March, whereas in Mysore district sowings commence in April-May and crop is harvested in October-November.

• The other growing areas including Assam, Bengal, Madhya Pradesh, Orissa, part of the Punjab.
• In Assam, Castor is mainly raised to feed the Eri silk worm.

• Despite phenomenal increase witnessed in the production and productivity of castor over the last ten years, there still exist wide regional disparities in the per hectare yields of castor.
• A multitude of factors such as its cultivation in submarginal and marginal lands under rainfed conditions with practically little or no inputs, use of poor quality seed and inefficient crop management are rersponsible for such dismal yield.
• The area under castor in Composite A. P. is gradually declined along with other crops in the last five decades.
• Ruling varieties and hybrids include Aruna, Sowbhagya, Bhagya, Kranti, GCH-4 and others. No significant change can be observed in the production of castor over the last five decades.

• Castor oil is unique in its chemical composition.
• It remains viscous at high temperatures and liquid at low temperatures.
• It is a non-drying oil. On account of this, it is considered as one of the best lubricants and is extensively used in the manufacture of lubricants.
• Before 1914-1918, railways used to buy large quantities of castor oil for lubrication. Some of the railways had their own mills.
• During the last two decades, castor oil has been replaced to a large extent by mineral oil.
• Castor oil is also used in various industries such as textiles, flour milling, as lubricant.
• Its medicinal use is known since a long time.
• Castor oil is used for lighting purposes in rural areas and some of the railways use it for lighting the signal and hand lamps.
• Castor oil and kerosene are mixed in the proportion of 7 : 1.
• It is estimated that about 5,000 tons of castor oil are annually utilised in the preparation of sulphonated castor oil, known as Turkey oil which is used in cotton dyeing, printing and leather industries.
• About 3,000 tons of castor oil are consumed in the manufacture of soaps.
• Castor oil imparts a certain degree of transparency to soaps.
• Castor oil soaps impart a shining and silky appearance to jute fabrics.
• Raw castor oil is used for promoting growth of hair.
• Castor oil is used in the manufacture of refined and perfumed hair oil.
• It is estimated that about 2,000 tons of castor oil are utilised for this purpose.
• Dehydrated castor oil is the largest new development for conversion to Sebacic acid, an important ingredient for the synthesis of Nylon fibre.
• Castor oil or its derivatives are used in the manufacture of disinfectants such as phenyles.
• About 1,000 tons of castor oil are consumed in this industry.
• The use of castor oil as a purgative is well known.
• About 2,000 tons of oil are consumed for medicinal purposes.
• In rural areas, castor oil obtained by boiling the seed, is considered better.

In medicinal uses, castor oil has to satisfy the British Pharmacoepia Standard as shown below :

• The oil for medicinal purposes is required to remain bright when cooled to 0⁰C and kept at that temperature for 3 hours.
• Its optical refraction should not be less than three to five.

• There have been no imports of castor cake.
• Before 1914-1918, United Kingdom and some other countries took some castor cake from India, but in recent years, the exports to other destinations have been negligible.
• But Ceylon is the only buyer outside India.
• The entire quantity of castor cake available is used as manure as it contains 4.5 per cent of nitrogen.
• Castor cake is mostly used for sugarcane fields as this cake is not attacked by white ants.