260 



THE AGRICULTURAL NEWS. 



August 24. 1918. 



THE CULTIVATION OF THE CASTOR 

 OIL PLANT, AND THE PREPARA- 

 TION OF THE OIL. 



Attention was drawn to the increasing demand for castor 

 oil in an article in \he .igrlailfiiral .Xeics, May 18, 1918. 

 This demand still continues, and in many of these islands 

 interest is being taken in the cultivation of the plant. 



Mr. A. E. Collens, Superintendent of Agriculture for 

 the Leeward Islands, delivered an interesting address on the 

 subject to the Antigua Agricultural and Commercial Society 

 on August 2, much of which is reproduced below. 



According to DeCacdolle, in his book 'The Origin of 

 Cultivated Plants", the castor oil plant is a native of Africa, 

 although it is now naturalized throughout the tropics. 



The oil has been employed for various purposes from 

 the earliest times. It is especially valuable at present as a 

 lubricant for fast moving machinery, particularly for aeroplane 

 motors, owing to the fact that it is unaffected by a wide 

 range of temperature. 



The medicinal use of the oil is well known, but it is also 

 valued in India as an illuminant, burning with a minimum 

 production of soot. It is also used in leather dressing, and 

 for fixing alizarine red in the dying of cotton. 



The leaves of the plant are employed in rearing a certain 

 type of silk-worm in India, and recently attention has been 

 paid to this matter in Trinidad. The leaves are also fed to 

 cattle in India, and are said to make excellent forage. 



With regard to cultivation, castor seed requires much 

 the same attention and cultural methods as cotton. It 

 thrives best on a rich, well-drained, sandy loam, and will not 

 do well on heavy wet soils, or ill-drained, swampy lands. 

 The root penetrate.s deeply, and therefore the land requires 

 to be deeply ploughed and well worked. 



Castor seeds have an extraordinary vitality; seeds known 

 to havj been kept for fifteen years in a stoppered bottle have 

 been sown in Queensland, and have produced healthy plants. 



Under normal conditions germination is slow, and the 

 seeds when sown may take a more or less prolonged time to 

 germinate. In modern pra<-tice it is advocated that the 

 seeds should be softened by having hot water (almost 

 boiling) poured over them, and being left to soak for twenty- 

 four hours before planting. 



The seeds are usually planted 6 feet apart each way, 

 three or four seeds in a hole. They usually germinate within 

 ten days. When the plants are 8 to 10 inches high they are 

 thinned out to one .stem in each hole. In the experiments in 

 Antigua the feeds were planted 4 feet by ') feet. If exten- 

 sive rultivation is undertaken, a space ."hould be left every 

 eighth row. to allow for the passage of a waggon or cart to 

 collect the seed in harvesting, .\bout 8 lb. to 10 lb. of seed are 

 required per acre. 



In from three to tour months the i)lants commence to 

 bear, and will continue in bearing for at least three months. 

 In the tropics the castor plant is a perennial, but it is ques- 

 tionable whether under cultivation it is desirable to allow the 

 plant to continue growing after six months. As the plant 

 ages it is liable to be attacked by scale insects, and apart from 

 that, the difBrulty of gathering the crop, and the diminished 

 yield indicate that at the end of six months it should be 

 ploughed up. If l-'ft alone, the plant would grow to an 

 inconvenient height. It should therefore be topped by pinch- 

 ing back the main stem when the plant is about 2 feet 

 high: this will cause the plant to throw out more fruit 

 npikes. When the capsules turn brown it is time to harvest 

 the seed. This is done by cutting off the spikes, and remov 



ing them to a barn to dry. The seeds should not ordinarily 

 be allowed to dry on the plant, as in some varieties the pods 

 are very apt to burst open automatically. 



Several methods are adopted for removing the woody 

 capsule. 



In the United States the spikes are spread out on a 

 drying ground to a depth of inches or 1 foot, according 

 to the weather. This drying ground niiy be either covered 

 or open; the floor should be clean swept or boarded; and it 

 should have a low wall or fence to prevent the seeds from 

 scattering when the capsules burst. If out of doors, means 

 should be available for protecting them from the weather, 

 e.g. by drawing them into heapa and covering them if riin 

 threatens. 



The spikes should be turned over frequently in the sin; 

 the capsules soon burst, and in four to five days they will 

 have shed their seed. The .seed is then winnowed free from 

 the husks. 



In the Bengal gaols the splitting of the shell is done 

 with a machine, which consists of two smooth iron rollers about 

 2 feet long, placed parallel to one another, and working 

 towards one another by a simple arrangement of cog wheels. 

 <)ne of the cylinders or rollers i.? fixed, the other movable by 

 a screw adjustment. By means of the latter contrivance the 

 space between the cylinders can be regulated to the re(|U;rsd 

 distance, the space being increased or diminished according to 

 the size of the seed about to be spilt. The great point is to 

 give tlie seed sufficient squeeze sc as to split the shell with':<ut 

 crushing the kernel. The seed can then be winnowed by 

 hand or by a mechanical shaker. 



Mr. Archibald Spooner, several years ago, while in 

 Antigua, experimented in castor oil cultivation and devised 

 a machine with a knapping action, consisting of two 

 horizontal superimposed wooden discs; the top of one was 

 fixed and the lower one revolved. The capsules were fed in 

 on the centre, and traveHed along grooves until they finiilly 

 came in contact with the fixed top disc, when the knapping 

 action caused them to split open. 



The yield per acre varies with the different kinds of 

 seeds, and also with the typo of hnd. In Madras, where 

 over .500,000 acres are planted in this crop, the normal return 

 ill dry lands is 200 lb. to ")00 lb. per acre, while in more 

 favoured localities up to 70<i Wj. are obtained. In Texas 

 and Florida yields as high as 2,700 lb. per acre are stated to 

 be obtained, while the average yield in the United States 

 varies from 700 lb. to 1 000 ft), per acre. In Oolo:i;bia 

 2 lb. per plant is stated to be the average yield, which appears 

 to be somewhat high; 1 lb. of dried seed per plant being 

 nearer the usual quantity. 



The following table represents some yields obtained in 

 the I>eeward Islands in recent years; — 



<"AI,rII,ArKl> VIET.liS I'KR .\(UK. 



Variety. Antigua. Nevis. 



1911. 1912. 11)1314. I9I7, 

 Hisinus coiumunis (major) — — — ."i.^O 



(minor) — — _ 460 



Zanzibarensis 980 390 1040 U.'iO 



Native large — — — 780 



Native small — — — . H.^ 



.■5172 1280 4.50 400 



,il7.'i — 420 .'560 



317.5 900 — — 



;jl7fi 780 330 460 



The yield varies greatly, but this may be partly due to 

 seasonal changes. The rainfall in 1912, for example, wan 

 abnormally low, the average being .'52 inches ,as against 

 a normal average of 1.5 inche.s for forty-four years. 



