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aT FORTNIGHTLY REVIEW 



OF THE 



IMPERIAL DEPARTMENT OF AGRICULTURE FOR THE WEST INDIES. 



ft.*TA;i/<rA«^ 



Vol. XV. No. 383. 



BARBADOS, DECEMBER 30, 1916. 



Price \d. 



CONTENTS. 



Page. 



Banana, Chinese, in 

 .Jamaica 124 



Cevli>n, Co-operative 



Credit in 429 



Coco-nuts in Ceylon, 

 Manurial Experiments 

 with 427 



Coco-nuts, Scheme for 

 Encouraging the Plant- 

 ing of 424 



Cotton Notes: — 



Britisli Cotton Growing 

 .Association 419 



Sea Island Cotton Market 4U» 



Cotton Selection and Seed 

 Supply in Montserrat . . . 427 



Crop Yields in England 

 and Wales 425 



Sugar Mills in the West 

 Indies, American View.s 

 on 425 



Department News 410 



Departmental Reports ... 422 



Fungus Notes: — 



The Fungus on Cacan 

 Thrips 430 



Argen- 



. Gleanings 



luseul Ncites: — 



Intercepting tli 

 tine Ant 



Pests of Sugar-cane in 



Britisli Guiana, II ... 



Items of Local Interest ... 



Lime Cultivation in Sierra 



Leone 



Lime Juice, Concentrating 



liy Freezing 



Lime Oil, Lu.xury Trade 



Restrictions .-ind tlie 



Price of 



Market Reports 



Nicotine as an Insecticide. 



Etiects of 



Notes and Comments ... 



Page. 



... 428 



42ti 



42ti 

 420 



425 



429 



Sugar-cane, Mulching 

 Sugar-cane, Notes 

 Transpiration in the 



Trinidad, Ordiiuuice 

 Regulate Fishing at 

 West Indian Products 



42:; 

 432 



... 42.S 

 ... 424 



.. 430 



>n 



... 417 



421 

 431 



Notes on Transpiration in the Sugar-cane. 



'ECEXT research on transpiration, having 

 [special reference to crop plants that grow in 

 ,the tropics, tends to show that the variation 

 in the amount of water lost is by no means entirely 

 governed by stomatal regulation or by any other simple 

 factor, and can only be e.xplained by a complex of 

 several factors. This conclusion has been arrived at in 

 America by Muenscher* who has compared, not merely 

 varieties, but different species of plants of very 

 distant relationship. 



*Internationtl Sugar Journal, October 191(5. 



In the Dutch Kast Indies. Kuyper** has carried 

 out experiments on transpiration in connexion with the 

 movements of the stomata and accompanying water loss 

 in sugar-cane. Abundant watering of the plots in 

 these experiments doubled the amount of water ordin- 

 arily transpired. As to the daily course of transpiration, 

 different varieties, it is claimed, may be arranged in 

 three groups, two of these attaining their maxima 

 respectively in early morning and at 11 o'clock, while 

 those of the third group show verj^ small differences 

 during the whole day. These differences in the utili- 

 zation of avadable water are supposed to correspond to 

 differences in production and in resistance to drought. 



In some ca.ses the daily loss of water was double 

 in one variety than in another. No connexion was 

 established between transpiration rate and stomatal 

 count of leaf area. The maximum transpiration rate 

 may be reached after the stomata have begun to close, 

 the rate of transpiration being in a measure independ- 

 ent of stomatal behaviour. Decrease or deprivation of 

 light decreases transpiration. The varietal differences 

 in transpiration rate are thought to be important as 

 giving a new basis for the selection of canes for certain 

 conditions of soil and climate. 



Although extensive observations have not been 

 made in the West Indies, there is evidence lo show 

 that certain varieties transpire verj' much more 

 rapidly than others. The e.^act cause for this has 

 n-ot been established, and it is probably due, as 

 already intimated, to a complex of factors comprising 

 environment and the constitution of the plant itself; 

 there is not much chance of a clear solution being 

 obtained. 



**Expenment titati«n Record, Vol. 35, No. 4. 



