\0L. XIII. Xo. 306. 



THE AQRIOULTURAL NEWS. 



19 



SUGAR INDUSTRY. 



EXPERIMENTS WITH SUGAR-CANE 



IN PORTO RICO, 1913. 



The sugar-cane experiments in this territory have been 

 carried on along the same lines as in 1912. In Bulletin 

 No. 5 of the Experiment Station of the Sugar Producers' 

 Association of Porto l!ico, where the results for 1913 are 

 recorded, attention is given first to the raanurial trials. It 

 is stated that an average yield of 3-l'49 tons per acre was 

 obtained from first ratoons by the use of a complete ferti- 

 lizer, or a gain of 608 tons over the non fertilized areas. 

 The series of tests to find out what effect, if anj', manures 

 have upon the purity and quality of the juice gave results 

 which show that neither the kind nor the amount of fertilizer 

 effects the sucrose and purity of the juice to any appreciable 

 extent. It is pointed out that tho.se plantations which are 

 making fertilizer tests can profit by this conclusion, as it 

 will not be necessary nor profitable tr make analyses of the 

 different plot.*. As regards the efi'ects of fertilizers when 

 applied to hill land, the re.'^ult of two years' work leaves no 

 doubt that fertilizing this class of soil with high-grade 

 chemical manures will pay handsoaiely. Their use over 

 a period of two years has doubled the jield (jf cane over the 

 plots not fertilized. Thus, contraiy to the general belief, 

 these hill soils respond more readily tn manures than do the 

 low lands. 



Interesting experiments were made during the past year 

 in connexion with hole versus furrow planting. There 

 appears to be no difference in the yield obtained under either 

 system of cultivation, but the advantage of planting in 

 furrows rests in the fact that it is much less expensive, and 

 that future cultivation, irrigation, and fertilization are 

 rendered more simple. The hole system is perfectly adapted 

 tfi poorly drained land where labour is cheap; but times have 

 changed, labour has become scarcer and higher, and a great 

 deal of land has been put into cultivation where drainage is 

 not the main consideration. Conditions to day require all 

 work possible to be done by animals and mechanical 

 implements. 



The experiments conducted by the Association on the 

 question of distance planting proved not only that close 

 planting results in a large increase of yield, but also indicate 

 the reason for this. Where cane is planted too far apart 

 there is not time the first year for it to stool out sufficiently 

 to cover the ground. There are theielore not enough stalks 

 per acre. 'I'he results showed that during both years the 

 weight of cane per acre was to a certain extent proportional 

 to the number of canes produced per acre. 



Of considerable interest in the West Indies are the 

 results obtained with seedling varieties. Of those which 

 have given satisfaction. Yellow Caledonia, B.3412, B.376, 

 B.4596, D.117, B.17.53, White Transparent and B.137C may 

 be- mentioned. In the selection of seedling varieties an 

 important factor which has to be considered is resistance to 

 the attacks of the white grub and other insects. Some of the 

 British West Indian varieties are useful in this respect. It 

 may be interesting to mention that 11.1753 is planted on the 

 limestone soils bordering the hills, and has been found after 

 long trial to be well adapted to this class of soil. Four 

 seedling canes have been very fully tested for two years in 

 the uplands. Of these B.206 came first with .ly^ tons per 

 acre and B. 1753 second with 33S; 11.306 was third and 

 1).117 fourth. 



In conclusion it should be stated that a large amount of 

 work is now being done in Porto Rico in the matter of raising 

 their own seedling varieties. It has been decided to adopt 

 the letter P to designate all seedlings produced at the 

 Experiment Station, whilst those raised at the Federal 

 Station of Porto Rico will carry the aEBx PR. 



THE MANUFACTURE OF WHITE SUGAR. 



Modern white sugar manufacture has as its principal 

 requirement the condition that a perfectly clear and lights 

 coloured juice shall be used as the material for crystalliza- 

 tion. As pointed out recently in the Ixttnuitional Swjar 

 Journal (December 1913), all new methods of juice 

 purification are directed towards this condition. In the 

 application of the single or double carbonatation process the 

 clearness of the thick juice leaves nothing to be desired, 

 but during evaporation the liquid becomes very dark in 

 colour owing to chemical changes between glucose and' 

 other chemical substances. It is frequently the case that 

 this difficulty is overcome by the employment of the acid- 

 thin juice process, which was described in the Agricultural 

 Neirs, Vol. XII, p. 355; but a useful alteration is the 

 method introduced by Messrs. Gordon of Wallaceburg, 

 Canada, and lately described in the Louisiana Planter 

 (December 13, 1913) 'The cane juire coming from the 

 cane mill is run through a heater and brought up to a sutti- 

 cientl}' high temperature to coagulate all of the free albumen. 

 The juice ihus heated and the free albumen coagulated are 

 then cooled down to a low temperature by a process the 

 reverse of the healing process — the use of a cold water cooler. 

 'Ihis seems to be the central idea of this new process: the 

 coagulation of the albumen contained in the juice before 

 liming and then having the juice cooled at once and thus 

 avoiding that inevitable inversion that results in the 

 ordinary method of clarification where lime is introduced 

 into the juice before this coagulation of the albumens has 

 been effected. This process avoids any destruction or elimin- 

 ation of glucosH, the glucose going in the molasses, thereby 

 retaining the value of this glucose instead of wasting it. 

 The juice thus cooled is then limed in excess and submitted 

 to the carlionatation process, the lime combining with the 

 organic acids of the juice and thus forming a flocculent 

 neutral juice, which, by the carbonatation process, the 

 carbonic acid combining with the lime, produces flocculent 

 neutral juice, which is reheated and readily passed through 

 filter pi esses, from which it emerges bright and clear as pale 

 sherry wine, and is ready for evaporation in the multiple 

 effects, and for concentration in the vacuum pan. From this 

 it emerges as pale coloured massecuite, and after centrifugal- 

 ing emerges as pure white sugar, which when passed through 

 the granulators, receives the final touch that makes the 

 produce pure dry granulated .sugars.' 



The Cu/-a Review (December 1913) reproduces from the 

 International Suyur Journal a portion of H. C. Prinsen 

 Geerling's paper dealing with the distribution of the world's 

 sugar. It will be remembered that British India consumes 

 her oivn produce together with the greater part of that of 

 ilauritius and one-third of that of Java. The United States 

 complement their own scanty production with that from 

 Cuba, Porto Rico, the Hawaiian Islands and many of the 

 Antilles. China and .Japan take their supply from Formosa 

 and ti> some extent from the Philippines, whilst Australia 

 depends on Fiji, Java, and Mauritius. South Africa uses the 

 sugar produced in Natal and Zululand, together with small 

 amounts from Mozambique and Mauritius, 



