558 



NATURE 



\pct. 9, 1879 



coffee from Ceylon, may be very distinctly traced. In 

 1869-70, before the disease had appeared generally upon 

 the coffee plantations, Ceylon exported 1,009,206 cwts. of 

 coffee, consisting of 860,707 cwts. plantation coffee, and 

 148,499 cwts. native coffee. In 1876-77, when there were 

 52,000 more acres in bearing, the total exports were only 

 797,763 cwts., viz., 727,420 cwts. plantation coffee, and 

 80,343 cwts. native coffee.^ 



The yield of native coffee ^ has been steadily declining 

 since 1868, owing to the want of high cultivation and 

 manuring which have, in some measure, at least, 

 saved the plantation coffee from being subject to the 

 full influences of the disease. The culmination of 

 crop and total value for native coffee was reached 

 in 1868, the year before the leaf disease appeared, 

 when 218,584 cwt. were exported. In 1877 the export 

 of native coffee had fallen to 76,182 cwts., only a little 

 over a third of what it was in 1868.^ The influence of 

 the disease has also seriously reduced the yield per acre. 

 The Rev. R. Abbay, in the paper mentioned above, states 

 that " Previous to and including 1871 the average yield 

 for five years over the whole island had been 4^5 cwt. per 

 acre, whilst for the five succeeding years the average has 

 only been 2 9 cwt. a decrease in the production of some- 

 what more than one-third." * 



The deficiency in value of crop has been variously esti- 

 mated ; " the average annual deficiency in the whole 

 island has been estimated by some as at least 2,000,000/. 

 Since the 'disease' made its appearance in i86g, the 

 coffee enterprise has suffered to the extent of from 

 12,000,000/. to 15,000,000/. in crops alone." ° A portion 

 of the loss which the coffee estates have suffered may be 

 and is, no doubt, due to exceptionally unfavourable sea- 

 sons for the blossoming and development of fruit, and to 

 the fact that many unsuitable areas were planted with 

 coffee, which have since become unproductive ; but there 

 is a marked difference in the uniform succession of crops 

 and in the yield per acre since 1 871, even in the best 

 coffee districts, which is evidently attributable to the 

 action of the coffee-leaf disease. 



When the trees are severely attacked by "disease," 

 there is a premature fall of leaf and a check to the 

 growth, which invariably results in a partial loss of crop. 

 The trees also appear much thinner than formerly, having 

 a wiry, sickly look, and do not make new wood so rapidly. 

 As the disease shows itself mostly in dry weather, and 

 just before the crop is ripening, its effect upon the trees 

 is more severe and lasting than it otherwise would be ; 

 the tips of the branches often die back, involving, as the 

 tree does not ripen all the berries, a great percentage of 

 light coffee and black-hearted beans. The vitality of the 

 trees being thus yearly weakened, there is often a failure 

 of blossom even in what may be called favourable sea- 

 sons, for though the blossom is forced out, it finds insuf- 

 ficient food-supply to support it, and, consequently, a 

 large and wonderful show of blossom often ends in a 

 total or partial failure of crop. 



It appears that during the earlier years of its ravages 

 the disease, after a very severe attack, would so com- 

 pletely disappear, and the trees, relieved from its en- 

 feebling effects, would put forth such an abundant supply 

 of new wood and foliage that it was confidently hoped 

 that it was only a passing visitation, and that it would 

 soon and entirely pass away. Even now its attacks are 

 often confined for some time to certain districts, and even 

 to certain parts of estates, but it seems to be seldom 

 absent from patches of old and ill-cultivated coTee, snd 

 from native gardens. It soon, however, became evident, 

 in spite of its fugitive charactei', that though the disease 

 did not completely kill any trees, its accumulative effects 



' " Ferguson's Directory of Ceylon,*' 1876-78 Introd. 



^ Unpruned coffee grows with little or no cultivation in Sinhalese gardens. 



3 The falling off in native coffee is possibly not quite so much as these 

 figures would indicate, for latterly an increasing quantity of native garden 

 parchment is shipped as plantation coffee. 



■* Lumean Society's Journal " Botany." vol. xvii. pp. 17VS' ^ Ibid. 



upon them, and especially on the older trees, were such 

 that they could not be depended upon to ripen their crop 

 or to produce, except in ahemating periods, a moderately 

 average crop. In 1874 Dr. Thwaites reported that " there 

 is great reason to believe, from what has been observed, 

 that high cultivation, with judicious manuring, enables 

 the tree to better sustain the attacks of the fungus, and 

 to retain strength and vigour enough to produce a fair 

 yield of berry." Encouraged by this opinion, planters 

 adopted manuring operations generally, not as a cure 

 for leaf disease, but in order to strengthen the trees 

 and enable them the better to bear the double strain 

 induced by crop and leaf disease. Though to some extent 

 successful, it was noticed that, with the leaf disease present, 

 the effects of manuring were not nearly so lasting as 

 formerly, and were seldom apparent after the first or 

 second year. There was also a less ready response on 

 the part of the trees, and cases were not infrequent where 

 trees had almost died out when forced to produce heavy 

 crops, and others, where trees in a large degree had ceased 

 to yield to any stimulus whatever. 



3. Remedial Measures. — From what has been already 

 mentioned it may naturally be supposed that the coffee- 

 leaf disease and its effect on coffee cultivation in the East 

 have occupied considerable attention during the last ten 

 years, and, indeed, it may be looked upon as the most press- 

 ing and momentous of all questions affecting the pros- 

 perity and welfare of Ceylon, which depends so largely 

 upon its coffee enterprise. Many suggestions have beer 

 made from time to time with regard to the application of 

 suitable and effective remedies. As early as 1869 the 

 Rev. M. J. Berkeley recommended the use of flowers of 

 sulphur, or " one of the sulphurous solutions recommended- 

 for the extirpation of the hop-mildew," but the fugitive 

 and deceptive nature of the disease and the vast area 

 (over 200,000 acres) to be treated prevented any decided 

 steps being then taken. 



The hopes that were entertained respecting the tem- 

 porary nature of the visitation and its possible mitigation 

 by the application of suitable manures also led planters 

 to look to indirect rather than direct means for checking 

 the ravages of the disease. A few experiments were 

 initiated, but from an imperfect knowledge of the disease 

 and want of suitable apparatus no satisfactory results 

 were obtained. 



In January of this year a series of systematic experi- 

 ments were initiated at Wallaha Estate, Lindula, in con- 

 junction with the Hon. G. A. Talbot. In these experi- 

 ments advantage was taken of the fact that the disease 

 in its first or filamentous stage appears to exist as an 

 external parasite upon the leaves and branches. It was 

 found experimentally that an application of flowers of 

 sulphur and coral lime entirely destroyed these external 

 mycelial threads and without inflicting the slightest injury 

 even to the most dehcate parts of the plant. 



This fact fully established, and being confirmed by 

 subsequent experiments on larger areas, gave an entirely 

 new aspect to the subject, and the present year has been 

 signalised by an earnest and it is to be hoped a successful' 

 attempt to reduce the ravages of the coffee-leaf disease. 



As sulphur had been used so extensively and so success- 

 fully against fungoid parasites in other parts of the world 

 it may appear a matter of surprise that no steps had been 

 taken long before this to test its efficacy on the coffee 

 plant. In order to treat this disease successfully, however, 

 it appears to be indispensable to carefully watch its 

 various stages and apply specifics only when the disease- 

 is mostly external During several months of the year, 

 especially during a continuance of wet weather, the vegeta- 

 tive system of the Hemileia seems mostly to be developed,, 

 and as the mycelial threads are present externally upon 

 the branches and leaves, it offers a favourable means for 

 being treated. 



Unfortunately the disease during this stage is entirely 



