10 



Various remedies have been tried. The gathering and burning 

 of the diseased leaves sometimes recommended gave poor results. 

 Enough of the fungus remains on the stems to serve to reinfect the 

 plant so that it is soon as badly diseased as before. The lime-sulphur 

 sprays, of which both the boiled and unboiled were used, were in- 

 effective, as was also the sulphur alone applied as powder. Bordeaux 

 mixture is really effective.^ The fungus can not grow on a leaf 

 covered with this spray, and it adheres better tlmn the other fungi- 

 cides, especially when made up with twice the usual amount of lime. 

 Owing to the frequent and heavy rains of the wet season even this 

 spray is washed off to some extent after a few days. In attempting 

 to increase the adhesion various substances were added to the mix- 

 ture, including borax, but the ordinary mixture with merely an extra 

 amount of lime was found to be better than any of these. In the 

 use of any spray material difficulties are met with, among which is 

 that of training the peon to direct the spray so as to cover the lower 

 sides of the leaves and to be thorough in the work, leaving no un- 

 sprayed, diseased leaves to serve as centers of infection. On many 

 of the trees reinfection takes place from the pieces of fungus threads 

 Avhich the spray has missed or which have been partly concealed 

 under the bark, making necessary repeated sprayings if the trees are 

 to be kept clean. It is possible to destroy the fungus entirely on 

 some trees by one spraying and to prevent the infection of healthy 

 trees to a large extent, but to exterminate the disease even with re- 

 peated sprayings is difficult. The work of one year seemed to indi- 

 cate that spraying furnished excellent means of checking the dis- 

 ease, but further work has shown it to be less satisfactory than it first 

 appeared. To open up the trees to the wind and air by felling the 

 shade could only have a bad effect on the coffee and is not to be 

 recommended. 



As. the nearest approach to a good way of controlling the disease 

 Bordeaux mixture made up with 4 pounds of copper sulphate and 

 8 pounds of unslaked lime or 16 pounds of air-slaked lime to 50 

 gallons of water applied as spray to the underside of the leaves is 

 recommended. In no event should a larger area be treated than can 

 be conveniently looked over from time to time in order to note any 



1 In case Bordeaux mixture is to bo used in any except very small quantities it will 

 be well to make up stock solutions of the required ingredients, and take from these from 

 time to time as needed. In this way it will be always possible to have a freshly made 

 up and effective solution, that having been made up for some time spoiling. The 

 ordinary mixture, 4 : 4 : 50 formula, is made by dissolving 8 pounds of the copper 

 sulphate in 25 gallons of water. The lime and water for the other stock solution is 

 made by slaking 8 pounds of live lime, using enough water to form a thin paste and 

 adding to 25 gallons of water. The Bordeaux mixture is made by taking one part of 

 each of the stock solutions, two parts of water, and agitating the mixture thoroughly. It 

 is often convenient to make the mixture in the spray pump. The formula used in the 

 work with coffee differs from the above in having twice the amount of lime, which has 

 the effect of making it adhere somewhat better to the foliage. 



