Vol. VII. No. 160. 



THE AGRICULTURAL NEWS. 



7»^ 



SUGAR INDUSTRY. 



Sugar-cane Experiments in Porto Rico. 



Sugar productiiin forms the chief industr}- of Forto 

 Eieo, tlie value of the sugar t'.vports during 1907 reach- 

 ing .S14,738,.572. It is eonhdently anticipated that 

 the output will continue to increase for several years 

 yet, and that with superior canes and improved methods 

 of cultivation, a larger return will be obtained per acre. 

 The Ann luiL Ri'porf {li)07) on the Agricultural E.xperi- 

 ment Station of the island mentions that work in the 

 production and trial of seedling canes is in progress, 

 and that many of these seedlings show a much higher 

 percentage of juice than the ordinary varieties culti- 

 vated. The following is taken from the section of the 

 report dealing with sugar-cane work : — 



Owing to the [injfitable nature of sugar-cane cultivation, 

 Porto Rican lilanters employ every means to grow a cane crop 

 year after year on the same land. As nitrogen is by far 

 the most expensive element of the fertilizer, and apparently 

 the one most needed, e.xperimeuts are being carried out with 

 a view of demonstrating the feasibility of supjilying this 

 element in the cane fields by the growing of leguminous crops 

 between the rows. Of the legumes being tested, the cowpea 

 (Viffna C'rt(^a/K/) and the horse bean (C'a«^H'a/fa ensiformis) 

 are the most promising, but several years' experimental work 

 will be necessary to determine the value of the system (if grow- 

 ing these crops on the same ground with cane. The cowpea will 

 mature in seventy days, so that a crop can be readily grown 

 between the rows after planting the canes and again after the 

 last flowering. 



Experiments with distances of jilanting in cane produc- 

 tion are being carried on for the purpose of determining the 

 method that will give the most cane per acre at the least cost 

 of production. The usual practice in the island is to plant 

 very close, 5 by 6 feet. The station's experiments have been 

 carried on with hill planting at distances of from .5 by 5 feet 

 up to 10 by 10 feet, and also in continuous rows. For the 

 first crop the narrow iilanting has given the heaviest yield. 

 As only one crop has been harvested from these plots, 

 figures on the ratoon crops cannot be given, but the 

 indications are that the differences in yield as between the 

 wide and narrow plantings on the second crop will 

 be less than in the case of the plant canes. As the 

 cane is an intensive crop, it seems advisable to grow as 

 much as possible each year on the same area, supplying 

 the drafts on the soil by the application of suitable 

 fertilizers, and avoid thereby the necessity of leaving the 

 lands idle for a series of years, for the purpose of recui)era- 

 tion. In proportion to the development above ground tlie 

 root system of the cane plant is not extensive, therefore 

 a very heavy tonnage can be taken from a small area. 



Some of the large sugar companies in Porto Rico have put 

 in steam ploughs which are going to a <lepth of 8 inches or more. 

 This is fo'iiid a very profitable ]iractice, giving large profits 

 for the cost of the work. After the canes are planted, more 

 thorough cultivation of the surface should bo given than is 

 •|i.sually practised. A great deal of hand labour should lie 



supplanted by the cultivator for reasons of economy. 



In planting cane it is a better praittice to open furrows 

 with the plough, it being less expesisive than cutting holes 

 with spades, as is usually do.ie. More^iver, by this method 

 the ground is stirred to a greater dypih a:ul a larger .surface- 

 is pulverized. From preliminary experiments at the station, 

 continuous rows have given larger yields than the same- 

 number of canes planted in squares. In planting in rows, canes 

 were stuck in the ground on end, as is the usual custom. The- 

 Hawaiian system of planting the canes in lines covered entirely" 

 with earth has also been followed. This is a lietter practice- 

 where the mole cricket (tSec/iteriiKyHs didactylii») does not 

 give too much trouble. Where this insect is prevalent, 

 however, the young seedlings are liable to be cut otf when 

 they break through the ground. If the canes are planted' 

 entirely below the surface, the young .seedlings will doubtle.ss 

 get more )iourishment than w-hen planted on end. Again, 

 when planted on end, the ants carry off a considerable 

 amount of the juice of the cutting, and some of it is lost by 

 drying out and rotting above the ground. From the one 

 crop of plant canes, the Hawaiian system gave more tonnage 

 than the similar plots iilanted in the native fashion, although 

 by the former method a small portion had to be replanted 

 liecause of the ravages of the mole cricket. 



Deterioration of Sugars on Storage. 



Under ordinary trade conditions sugar is freipient- 

 ly kept in storagi' for more or less lengthy periods, and 

 in those circumstances it is liable to undergo fermentive 

 changes whereby the amount of sucrose present is- 

 decreased. This question, in regard to muscovado sugar, 

 was dealt with by Dr. Francis Watts, C.M.G, and 

 Mr. H. A. Tempany, B. Sc, in a paper contributed to the 

 West Inilian Bulletin, Vol. VII, p. 226. The work of 

 these two investigators indicated that the fermentation 

 changes were induced lay a micro-organism, which might 

 be destroyed on sterilization by heating. 



Further investigations on this subject have been 

 lately carried out at the Hawaiian Experiment Station, 

 and the results of the work are embodied in Bulletin 34, 

 issued by the Station. The following is a summary of 

 the chief conclusions arrived at : — 



In the great majority of cases deterioration in stored 

 sugar is the result of bacterial activity, but a fall ia 

 polarization sometimes occurs without any evidence of this 

 being due to bacteria. 



The presence of moisture is necessary for the bacterial 

 action to take pUu-e, but so long as the sugars do not 

 contain more than 1 ]>er cent, of moisture, the danger of 

 bacterial action is small. 



Four distinct organisms are often present in Hawaiian 

 sugars, and one of these was of very frequent occurrence ia 

 sugars whicli deteriorated. 



The capacity of sugars for absorbing moisture varies- 

 largely, and this is an impoftant factor in determining the 

 keeping qualities of the sugai-^. Some evidence exists that 

 the quantity of moisture absorbed is connected with the 

 amount of chloride present in the sugar. 



In factories where trouble is experienced on account of 

 the deterioration of sugars, the provision of an interior paper 

 lining to vessels containinc; the sugar might be of service in 

 protecting the contents from the influence of atmospheric 

 changes. 



