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COFFEE 161 



seen unless the leaf is held to the light. As the spot 

 increases in size it assumes a faint yellow colour, and 

 finally the under side is covered with a bright yellow 

 dust which soon becomes a bright orange colour. The 

 spots now vary in size, but are circular in shape except 

 where they coalesce. Although the infections occur on 

 the young leaves, the spots do not develop until the 

 leaves are older. They are usually most numerous 

 near the apex. In June and July the disease becomes 

 most severe, and thousands of spots in all stages 

 are visible, each producing great numbers of spores. 

 Many of the young shoots perish, and the berries are 

 poor or worthless. The severity of the disease depends 

 somewhat on the weather, but there is very little cessa- 

 tion until the dry season sets in. The spores are 

 produced in great abundance in the orange-red spots, 

 and are carried by the wind or insects to the young 

 leaves where they germinate within about twelve hours 

 and penetrate the leaves through the stomata. The 

 young leaves, being much more tender and retaining 

 moisture on the surface much longer than the older 

 ones, are much more susceptible to the attacks of the 

 fungus. It is said that each spot will give rise to 

 about 159,000 spores per day, and that as many as 

 60 or 70 spots will be borne on a single leaf. It is 

 claimed that the spores from the fallen leaves will not 

 germinate, and therefore their removal will not be of 

 any consequence in checking the ravages of the disease. 

 The spores are said to be easily killed by spraying with 

 tobacco water and Bordeaux. 1 



The disease is very widely distributed throughout 

 the coffee -growing regions of the old world, having 

 been reported from Burma, Ceylon, India, Tonkin, 

 China, Coorg, Malay, Phillipines, Natal, Transvaal, East 

 Africa, Malacca, Sumatra, Java, Fiji, Singapore, Samoa, 

 Mauritius, Madagascar. It has also been reported from 

 some of the American tropics, but the writer is reason- 



1 This fungus is sometimes attacked by another fungus, Aspergillis sp. r 

 and also by the larva of some insect. 



M 



