Vol. IX. No. 208. 



THE AGRICULTURAL NEWS. 



119 



it is natural that the flower-bud maggot causes greater appre- 

 hension to cotton-growers in Antigua than any other insect 

 pest. The gist of Mr. Tempany'.s observations in connexion 

 with the maggot is given in the Insect Notes of this issue of 

 the Agriciiltuial News, together with further information by 

 the Entomologist to the Department. The fact of greatest 

 importance in connexion with the matter is that the best 

 means for combating this pest is provided by early planting. 

 The matter has been dealt with quite recently in the Agricul- 

 tural Neti's (Vol. IX, p. 86), and may be resolved by saying 

 that the sowing of cotton .should be done as early as possible 

 after the end of May, given sufficient rainfall to ensure 

 successful germination and a good stand of plants, and if this 

 condition has not been fulfilled by the end of July, the idea 

 of growing cotton must be abandoned, and its place taken by 

 some other suitable crop, or crops. 



The yields of cotton have varied to a large extent on 

 ditterent estates: they have been most generally affected by 

 the degree to which the attacks of the flower-bud maggot 

 have taken place in the different districts. The best yield, so 

 far, has been obtained at Crumpland, an estate in the north- 

 eastern part of the island, where there has been a return of 

 nearly 1 bale (230 lb.) to the acre. The amount of cotton 

 that had been ginned in the island up to March l.S was 104 

 bales of 230 lb. weight, and there was material in store for 

 making 11 bales more, so that the amount of lint that had 

 been picked, up to that date, was 11.") bales. It is possible, 

 according to Mr. Tempany's estimate, that under the most 

 favourable circumstance.s, 1.50 bales will have been .shii)ped 

 by the end of the season. If this forecast is realized, the 

 yield of lint per acre will have been 1 36 lb. This is a much 

 greater return than any of those of the last three crops, 

 which were as follows : — 



Year. Lint, lb. 



1906-7 lOOo 



1907-8 730 



1908-9 56-6 



This is a subject for encouragement, and would seem to 

 show the wisdom of early planting. The matter is summed 

 up in the report from which the above information is obtain- 

 ed, by the expression of the probability that the future of the 

 cotton industry in Antigua will depend, to an extent, in the 

 districts where the flower-bud maggot is present, on the 

 ability to obtain a profitable first picking before the middle 

 of December. 



COMPOSITION OF THE LATEX OP SOME 



RUBBER TREES. 



Analytical notes of rubber plants that are growing 

 in the Botanical Gardens, Singaporo, are given in the 

 Agricultural Bulletin of the Straits and Federated 

 Malay States for February, 1910. The information that 

 appears in relation to Para rubber trees {Herea hrasili- 

 ensin), a West African rubber vine (Landolphia 

 Hcudelotii), and Ceara rubber {Manihot Glaziovii) 

 is reproduced below: — 



HEVEA BEASiLiENSis. The latex was obtained from one 

 32-year old tree, tapped at 6'30 a.m. No water was added 

 to the latex, and the formalin used was carefully measured, 

 so that the amount of latex is known. In the figures given 

 below, this formalin has been corrected for; thus they refer 

 to pure latex. 



The total yield from this tree at one tapping was 27 

 fluid oz. of latex. It was thick, white, and of very agreeable 

 odour. 



The coagulum obtained by use of acetic acid was 

 analyzed, and the amounts of several of the other constituents 

 determined. The dry rubber has the following composition: — 



Per cent. 

 Rubber 98-14 



Resin 1-86 



Albumens were not determined (as they should be for 

 strictly accurate results). Their amount is small, compared 

 to the total, and the usual acetone extraction gives figures 

 that are near enough to the truth for all ordinary purposes. 

 The analysis of the latex is: — . 



Per cent. Per cent. 



(Rubber 35-5.5 



Coagulum 36-29 -Resin 067 



[Ash 0-07 



Serum solids 2-63 /Organic matter 2-30 



(.Ash 0-33 



Water 61-08 Water 61-08 



The solids soluble in water (tannins, colouring matters, 

 pentoses, gums, sugars of the inosite group, etc.) form a 

 brown, sweet-smelling mass of an extremely hygroscopic nature. 

 The strength and ai)pearance of the rubber were very fine. 

 The proportion of 30 per cent, coagulable matter in the 

 latex is very high for Para, and is in accordance with the 

 rule that the percentage of rubber in a latex increases as the 

 tree gets older. 



LANDOLPHIA iiEUDELOTii. The Specimen examined was 

 a bush in the liotanical Gardens, growing in an inferior clay 

 soil. It was only a few feet in height, with a diameter of 

 about 2 inches on some of the branches, the basal stem being 

 larger. 



The latex ran very slowly from transverse cuts, and 

 coagulated rapidly. The rubber was obtained by picking 

 the clots from the cuts, and was handsome and strong. 

 The analysis of the dry rubber is : — 



Per cent. 



Rubber 8950 



Resin IO.jO 



The dry rubber is of a clear light brown colour, not 

 tacky, and very strong and elastic. Comjjared to Willughbeia 

 rubber, it has a better colour, and the resin content is less. 

 It is, therefore, a better rubber, as far as can be judged with- 

 out vulcanization tests. 



MAXiHor i;laziovii. The specimen examined was taken 

 from a large tree in the Botanical Gardeu.s, Singapore. The 

 bark was quite unlike that of most rubber plants, having 

 a very thin outer layer. This came away from the tree very 

 readily when the knife \\ as userl, and a large surface of it was 

 stripped back. On this exposed place, a herring-bone tap 

 was made, the plant was re-tapped again on the following day, 

 and again two days later. The latex tubes are very near the 

 outer surface of the inner bark, and these few successive tap- 

 pings did not increase the flow of latex to any appreciable 

 extent. 



LTnlike that of Hevea brasiliensis, the latex coagulated 

 quickly in the cut, so that the flow ceased almost immediately; 

 in fact, it was quite impossible to collect it in cups for this 

 reason. The rubber was obtained by stripping it from the 

 cuts. It had a very disagreeable herb-like odour. Analysis 

 gave the following figures, calculated to dry weight : — 



Per cent. 



Rubber 90-44 



Resin 6-83 



Ash 2-73 



The rubber is fine and tough, tougher than plantation 

 Para, and very light straw yellow in colour. The ash could, 

 of course, be reduced to a negligible amount by washing. 



