Edible Products. 



210 



[March 1908. 



growth, the lead was taken by ' blue 

 top ' which gave the enormous return of 

 21*9 tons of tubers, containing over 7 

 tons of starch, per acre. 



These results indicate that in the Ligu- 

 anea Plain, it would be advisable for a 

 starch factory to put in half its area in 

 ' white top,' for quick returns, and the 

 remainder in ' blue top ' grown as a 

 biennial. 



It has still to be ascertained whether 

 the practice in the East Indies of 

 harvesting the mature tubers without 

 destroying the plant, and leaving the 

 small ones to grow on, is suitable 

 for large-scale cultivation in Jamaica. 

 In friable soil where the tubers 

 are readily accessible, the treatment 

 of the cassava plant as a perennial 

 on this basis might prove to be sound 

 practice. The chief omen against the 

 success of this method is tnat it would 

 most certainly have established itself to 

 be the custom of the country, had it 

 been from objection ; since many gener- 

 ations of estate cultivators, inspired by 

 the genius of the empty stomach, have 

 been growing cassava in this island, and 

 it is certain that this must have been 

 well tested in previous ages. 



COST OP PRODUCTION OP TUBERS. 



The cost of growing cassava on a large 

 scale in Jamaica has been studied by 

 Messrs. J. W. Middleton, Joseph Shore, 

 the Hon. H. Cork, the Hon. J. V. Calder, 

 and at the Hope Experiment Station. 

 It has been deduced from the figures put 

 forward, that cassava should cost, for 

 cultivation only, from £3 13s. to £5 per 

 acre, according to locality and circum- 

 stances. 



The lower price represents the esti- 

 mated cost under the most favourable 

 conditions of broad-scale implemental 

 culture on friable soils, while the higher 

 price would be the cost of cassava farm- 

 ing on rocky land by hand labour. 



An average cos t of £4 per acre repre- 

 sents the estimated cost under favour- 

 able conditions of estate cultivation. 



The Hon. Henry Cork has estimated 

 that a capital of £1,600 to £2.000 would 

 be required for starting a cultivation of 

 100 acres of cassava on new land. Allow- 

 ing 10 per cent, on capital and 20 per 

 cent, on live and dead stock account, 

 Mr. Cork's estimate sets the actual cost 

 of such a cultivation at £6 to £8 per 

 acre. With regard to the yield of tubers 

 to be expected, it would appear that an 

 8-ton crop should be a fair average, while 

 good lands with efficient tillage should 

 return 10 tons and more per acre. These 

 figures indicate that cassava can be grown 

 in Jamaica at less than £1 per ton. 



Should cassava farming be started, it 

 would be desirable for the purchasing 

 factory to pay on the starch value of the 

 tubers. We have found from experi- 

 mental trials that the specific gravity of 

 cassava tubers bears a definite relation 

 to the percentage of starch they contain, 

 and that it is possible approximately to 

 ascertain the starch value of cassava 

 tubers by means of the potato balauce, 

 used on the Continent. A table is being 

 prepared, giving the approximate starch 

 content corresponding to the readings 

 of the cassava balance, which should 

 be useful to buyers of cassava in 

 arriving at a fair price for the purchase 

 of cassava tubers from contributary 

 growers. 



MANUFACTURE. 



Much has still to be worked out as to 

 the most efficient plan for dealing with 

 the cassava grown in Jamaica, for the 

 manufacture of starch, cassaripe, and 

 cattle food. The first process is that of 

 washing and decorticating the tubers. 

 For this purpose the simple machine 

 recently devised by the Hon. T. H. 

 Sharp, which I have seen at work at 

 Eltham Park, appears to be entirely 

 satisfactory. 



The great cost of peeling tubers by 

 hand in the early experiments is thus 

 entirely avoided, and the tubers ai*e 

 automatically washed and delivered free 

 of the cortex by the operations of this 

 machine. This invention has solved one 

 of the outstanding difficulties that faced 

 the starch producer in Jamaica. 



To secure an efficient recovery of 

 starch, the finest possible disintegration 

 of the cut-tissues of the cassava is 

 necessary. There are mills now obtain- 

 able that give excellent results and pro- 

 duce a very fine disintegration at a high 

 rate of production. 



A second grinding or disintegration 

 should be carried out where starch is the 

 main object of manufacture, but where a 

 good market can be found for the dried 

 residue as a cattle food, the second mill- 

 ing may probably be disregarded. 



The sieving, purification, settling, 

 refining, and drying of the starch seem 

 all to be capable of easy accomplishment 

 with suitable machinery, and there is 

 now no doubt at all, that a starch fac- 

 tory to produce 1,000 tons of starch a 

 year could be erected with every cer- 

 tainty of producing a high grade of 

 cassava starch. Such a factory should 

 not cost more than £6,000 or £7,000 

 to erect, and, with intelligent manage- 

 ment, a satisfactory result should be 

 assured. 



