FuNc.oi!s DiSLASiiS oi' PiANis, Pi:.\( n Vi:i.i.ows 143 



berry bushes or forbidJinq by law their being planted near wheat 

 fields/" 



Erwin Smith followed with interest the study made by Harry 

 Marshall Ward''" of a leaf disease of coffee trees on the island of 

 Ceylon. Ward was an honor graduate of Christ College, Cam- 

 bridge University, England, a science student of the Science and 

 Art Department at South Kensington, and a former student of 

 Sachs at W'^iirzburg and of DeBary at Strassburg. When he began 

 his investigations of the coffee disease, the losses were already 

 estimated in millions'of pounds sterling.^'' Year after year, this 

 ravage destroyed foliage on whole areas of coffee plantations, dis- 

 couraged planting, and threatened to change, as it finally did, the 

 center of the coffee growing industry from Java and the English 

 Indian Ocean Empire to Brazil and South America. ^^ Ward 

 proved that a fungus, Heniileia vastatrix, was the cause, and that 

 fungicides had to be applied to the foliage at a precise time antici- 

 patory of the fungus and its recondite development, to wit, 



after the spore, germinating on the leaf -surface, had put out its delicate 

 germ-tube but before this germ-tube had time to penetrate through a 

 breathing-pore into the leaf-interior. "" The life of the parasite," [Ward 

 said} "is so arranged that as short a time as possible shall intervene 

 between the well-protected spore condition and the safely ensconced 

 mycelium." *^ 



Fungicidal treatments — lime and sulphur among them proved 

 efficacious — were applied so as to be " ' already on the leaves ivhen 

 the spores were germinating! " The next best method practically 

 available when the malady occurred was to plant the areas affected 

 with crops not subject to attacks from the fungus. Some control 

 was achieved by protecting cultivated species of coffee by natural 

 or artificial windbreaks, wild species being noticed to be compara- 

 tively unharmed and could form a barrier against "spore-laden 

 winds." Still another method used in Africa was to restrict coffee 



'° B. T. Galloway, Progress in treatment of plant diseases, op. cit., 192 ; ]. C. 

 Arthur, op. cit., 153-155; E. C. Large, op. cit., 131-135. 



"H. H. Whetzel, op. cit., 100-102; E. M. Freeman, Harry Marshall Ward, 

 Fhytopattoology 3 (1): iff., 1913. 



'* Fifty years of pathology, op. cit., 19; also, E. F. Smith, The coffee disease of 

 Ceylon, Science 23 (575): 80, 1894. 



^' E. C. Large, The advance of t/je fungi, op. cit., chap. XV, 196-208. 



*" E. C. Large, op. cit., 205-206. 



