Vol. XI. No. 264. 



THE AGRICULTURAL NEWS. 



181 



intensity is greatly affected by external conditions. The im- 

 portance of the disease as a controlling factor in sugar-cane 

 cultivation is gaining in appreciation, but it is only where it is 

 completely recognized that remedial measures can be applied 

 with real prospects of success. 



Peasant canes have continued to be purchased at the 

 Gunthorpes and Bendals factories in Antigua During the 

 year the former purchased if, 542 tons, and the latter 4,176 

 tons of peasants' canes. There is no doubt that the provision 

 of an adequate market for peasant-grown cane has had a con- 

 siderable effect in improving the position of the peasantry in 

 Antigua. 



The year may, on the whole, be said to have been dis- 

 tinctly satisfactory as regards ths cotton industry. As the 

 outcome of the favourable results obtained in the previous 

 year, considerable increases in the area planted under the 

 crop occurred in all the Presidencies. 



Moderately favourable weather was on the whole 

 experienced, and satisfactory yields were almost everywhere 

 obtained. A notable feature of the season was the relatively 

 small prevalence of insect pests. Prices declined somewhat from 

 the high value of those in the previous year, and during the 

 earlier months of 1911, owing to trade depression in England, 

 the product was difficult of sale. At the time of writing 

 the bulk of the crop has been disposed of at fairly satisfac- 

 tory prices. 



The cultivation of limes continues to occupy the position 

 of principal agricultural industry in Dominica, and further 

 expansion has once again to be recorded. The crop for the 

 year was 369,0C0 barrels, an increase of 8.5,000 barrels 

 over the crop of 1900. This remarkable increase is partly 

 attributable to the coming into bearing of young plantations 

 established within recent years. Considerable efforts con- 

 tinue to be made by the Permanent Exhibition Committee of 

 Dominica to popularize limes in England and Canada by 

 means of judicious advertisement and representation at 

 exhibitions. The export of citrate ©f lime amounted to 

 .5,194 cwt., valued at £16,880; this showed an increase of 

 1,747 cwt. over the export of 1909. 



In Montserrat, the total exports of lime products were 

 valued at £9,000. Trouble continued to be experienced in 

 connexicm with scale insect pests. 



In Antigua interest in the crop continues to grow, and 

 considerable increases are being made in the areii planted 

 under the crop, especially in the southern district of the 

 island. In Nevis also, interest in the crop continues to 

 grow, while in the Virgin Islands attempts are being made 

 to foster the growth of a small industry. 



In Dominica the cacao crop amounted to 11,012 cwt, 

 valued at £23,769, a small increase over the exports of the 

 previous year. Small exports of cacao were again made 

 from Montserrat. 



Interest continues in the possibility of cacao production 

 in suitable localities in St. Kitts and Nevis. The plantations 

 are small in area: that in St. Kitts has been .slightly extended, 

 but the total amount of land suitable for tl>is- form of culti- 

 vation is relatively small. 



Rubber-growing is now attracting considerable attention 

 in Dominica. Trials have shown that the Para rubber tree 

 {Hevea brasi/iensis) grows well under the conditions obtain- 

 ing in many localities; an appreciable area has already been 

 established under the crop, and this is being considerably 

 extended. It is hoped that this form of cultivation may prove 

 especially suitable to the conditions obtaining in the interior 

 lands of the island. 



The cultivation of coco-nuts continues to attract atten- 

 tion in Antigua and Nevis. About 200 acres have already 



been established under the crop in each of these islands, and 

 the area is being extended. The older trees present a pro- 

 mising appearance, especially in Nevi.s, where they are now 

 coming into bearing. Should these pioneer plantations prove 

 financially successful, it appears probable that they may lead 

 to considerable fixrther developments in this direction in the 

 future, as the Colony possesses considerable areas of land at 

 present in waste, which appear likely to be well adapted 

 to this form of cultivation. 



The possibilities of vanilla cultivation on a systematic 

 basis are now engaging some attention in Nevis and Dominica, 

 and small trial plantations have been established: the develop- 

 ment of these attempts mil lie watched with interest. 



Onion cultivation for export continues to be carried on 

 with success as a small industry in Antigua The onions are 

 chielly grown as a catch crop on land prepared for cane plant- 

 ing. In the other islands onions are raised in small quanti- 

 ties, chiefly for domestic use. (From Colonial Reports — 

 Annual, No. 711, p. 10.) 



CARBON ASSIMILATION IN PLANTS. 



The leaf of a plant has been likened to a factory 

 engaged in elaborating complex substances from the simple 

 raw materials supplied to it. In the case of the carbohyd- 

 rates, the final product, starch, and the .simple raw materials, 

 carbonic acid and water, are known definitely, but there is 

 some uncertainty as to which of certain sugars are formed as 

 intermediate products of as.similation. It is now some years 

 since Brown and Morris brought forward experimental 

 evidence, based on the study of Tropaeolum, to prove that 

 the first sugar to be synthesised by the leaf is cane sugar. 

 When the concentration of this sugar exceeds a certain 

 amount, it is transformed into .starch, which is a more stable 

 and permanent reserve material than sucrose. These con- 

 clusions have not escaped criticism, but it is only recently 

 that fresh experimental evidence on the subject has been 

 obtained by Parkin, in England, and Strakosch, in Austria. 

 Parkin selected the snowdrop for his experiments, choosing 

 it because it is one of the few plants which do not elaborate 

 starch in their leaves. It is therefore a more simple material 

 for investigation than the Tropaeolum. Parkin comes to the 

 same conclusion as Brown and Morris, namely that 

 cane sugar is the first product formed. Subsequently 

 it is broken down by an enzyme in the Ie*f into 

 the more simple sugars dextrose and levulosc, which 

 according to the older views of Sachs and others, are 

 these first formed in the leaf The older view, how- 

 ever, has received some confirmation in the work of Stra- 

 kosch, carried out with the leaves of the sugar beet. 

 Using a somewhat different method for determining the sugars 

 from that employed by the English workers, he claims that 

 dextrose is the first sugar to appear, part of it soon becoming 

 transformed into levulose, and the two combining to form 

 cane sugar. Starch is only formed when a considerable quan- 

 tity of cane sugar has accumulated in the leaf sap. The cane 

 sugar produced in the leaf of the beet travels in this form to 

 the root to be stored: in the Tropaeolum, Brown and ilorris 

 considered that cane .sugar is not translocated as such, luit in 

 the form of its simple components — dextrose and levulose. 

 A .similar conclusion is reached by a study of the beet in the 

 second year of growth. The cane sugar stored up in the root 

 is translocated to the growing parts as a mixture of dextrose 

 and levulose, which are recombined on reaching their destin- 

 ation. The evidence at present seems to favour the retention 

 of the view expressed by Brown and Morris; but it is evident 

 that the problem is not fully solved. (The Gardeners' Chron- 

 irle, April 20, 1912.) 



