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COTTON DISEASE. 



From Commissioner, Imperial Department of Agriculture, to Director 



of Public Gardens. 



Imperial Department of Agriculture for the West Indies, 



Barbados, January 23, 1906. 

 My dear Fawcett, 

 I am in receipt of your letter of the 8th instant advising the 

 sending of some bolls from Mr. DeMercado's cotton in Vere ap- 

 parently attacked by anthracnose. 



I enclose for your information a report prepared by Mr. Stock- 

 dale on the samples sent. 



With kind wishes, 



Very sincerely yours, 



(Sgd.) D. MORRIS. 



Imperial Commissioner, 



The four cotton bolls forwarded by Mr. Fawcett from Mr. De 

 Mercado's estate in Vere are small and ill-shaped. Two of these 

 show the characteristic spots of anthracnose, from which spores of 

 Colletotrichum gossypii are given off. These spores appear to be of 

 a greater diameter than those described by Mr. Lewton-Brain (W. 

 I. B., Vol. v., p. 191) as Colletotrichum gossypii var. harhadcnse, and 

 I should be pleased if Mr. Fawcett could obtain further specimens, 

 so that this difference might be looked into more fully. 



The spots of anthracnose on these two bolls were over-grown 

 with Fusarium which is probably saprophytic (West Indian Bulle- 

 tin. Vol. v., p. 178). The other two bolls show no signs of 

 anthracnose, but appear to have been dried up through some 

 purly physiological causes and have subsequently become covered 

 with Fusarium. I have seen many such examples in Barbados this 

 year, more frequently immediately after changes of weather when 

 the plant does not seem able to support or properly feed a large 

 number of bolls. 



Suggested Remedial Measures — The fungus that causes the An- 

 thracnose spreads by means of spores which are disseminated by 

 wind and insects and is capable of growth on all parts of the 

 plant. If the area is badly attacked it would be advisable to 

 destroy all diseased plants and parts of plants and not to set 

 cotton in the infected area for a few years. 



If a young crop of cotton is badly infected, spraying with Bor- 

 deaux mixture would probably prevent the germination of spores 

 and so prevent further infection of bolls. This must not be done 

 if any of the bolls are matured, as the solution of copper salts 

 would seriously discolour the lint and therefore reduce its value. 

 If the crop of cotton is advanced and the disease is doing serious 

 damage, experiments with dry fungicides might be conducted, say 



