A FORTNIGHTLY REVIEW 



OF THE 



IMPERIAL DEPARTMENT OF AGRICULTURE FOR THE WEST INDIES. 



LIBt 

 NEW 

 B0TA 



QAR 



Vol. X. No. 244. 



BARBADOS, SEPTEMBER 2, 1911. 



PuicE Id, 



CONTENTS. 



British (iuiana. Trade aiul 

 Commerce of, 1910-11 



Calcium C'janamide as 

 a Manure, Use of ... 



Canadian iSiational E.\liibi- 

 tion, 8t. Vincent and 

 the Virgin I.sland.s at 



Cas.sava from Reunion ... 



Cotton Notes : — 

 Caravonica Cotton 

 Cotton ill Algeria 

 West Indian Cotton ... 



Dominica, Green Dressing 

 Trial-, in 



Fibre Plant, New 



Fiji, Sisal Fibre-Cleaning 

 in 



Fungus Notes : — 



Tlie Die-I)ack Fungus of 

 Para Rubber and of 

 Cacao 



Gleanings 



Growth of Stems, Eftects 

 of C'oui]iie.s.sion on ... 



Pack. 



281 



281 



Page. 



287 

 276 



278 

 278 

 278 



277 

 28.5 



283 



28G 

 284 



281 



Insect Notes : — 



The Mango Weevil .. 282 

 Light and the Growth of 



Trees 273 



ManurinL; and Meat Prfi- 



duction 283 



Market Reixa-ts 288 



Non-i)roteid Bodies, Use 



of, by Animals ... 281 

 Notes and Comments ... 280 

 Periodicity ir. Yield of 



Plantation Crops ... 280 

 Pine-Ap]ile <irowing and 



Manganese Soils ... 27G 

 Rubber L.ite.x, Acetic Acid 



Coagulation of 279 



Rublier Supply to the 



United Kingdom .. 279 



Students' Corner 285 



Sugar Industry : — 



Sugar in Cuba in 1910 27n 

 West Indian Products ... 287 

 West Indies in Canada, 



1911 280 



Light and the Growth of Trees. 



[tKE.S, like all other green plants, require 

 light, in order that they may [iroduce material 

 ^for the new growth without which they 

 cannot remain alive. This makes it evident that, 

 where a large number of trees are existing together, 

 the extent to which their requirements are satisfied in 

 the matter of light determines the number that are 

 standing on a imit of area, as well as the manner of 



growth in those which continue to live. The importance 

 of the proper .'upply of light to trees has been recog- 

 nized first, in an organized, practical manner, in forestry, 

 and it will be well to give short attention to a recent 

 publication* which presents particulars of the latest 

 c .nsiderations and results belonging to the subject. 



In this Bidletin, reference is first made to the ways 

 in which plants are affected by light. They are influ- 

 enced by this in the building up of food materials, and 

 it is a'so responsible for the structure, form and colour 

 of the leaves, and the form of the stem and of the crown 

 of the tree. In collections of trees, as in forests, the 

 grortth in height, the rate of thinning out and of 

 natural pruning, the character of the smaller plants 

 growing under the trees, and the vigour of the j^ounger 

 trees, are all matters that are determined by the supply 

 of light. It is the recognition of this fact that has 

 stimulated enquiry into the subject, in order that those 

 responsible for forest work may be in possession of 

 accurate information concerning the light required by 

 trees, when growing together. 



It must be remembered that plants are subjected 

 to two kinds of light — direct and diffused, and that the 

 proportion of the former is increased as the equator 

 is approached, while they both decrease in amount 

 with increase of latitude. Height above sea-Kvel 

 also affects the ratio of these two kinds of light: 

 the greater the altitude the less is the amount 

 of diffused light, and the larger the quantity of 

 that which is direct. As far as a plant in any given 

 position is concerned, this is illuminated by light 

 which reaches it in different ways, the kinds being 

 overhead light, which is the strongest, side light, light 



♦Bulletin 92 of the Forest Service of the United Stat-es 

 Department of Agriculture, entitled Light in Relation to Tref 

 (iroicth. 



