66 THE COFFEE-LEAF DISEASE. 



2. — A leaf of the coffee attacked at numerous points by such 

 germinating spores rapidly succumbs to the ravages of the 

 mycelium, and falls long before it would normally have done so ; 

 not only by directly robbing the tree of food prepared by the 

 labours of the leaf, but, further, by occupying space and shortening 

 the period of usefulness of the leaf, is the tree injured. 



3. — The loss of matter and functional disturbance brought 

 about by these continued and periodical ravages have for effect a 

 diminished power to mature crop on the part of the coffee ; and 

 flower-buds, flowers, and berries fall because the nutritive relations 

 between the shoots, leaves, and flowers have become overthrown. 

 More crop is borne, as a rule however, where the trees contain 

 more food material to support it. 



4. — The spores of Hemilela are carried by wind. Whether a 

 spore travels a long distance in one journey, or whether it is swept 

 along in successive leaps, it may be carried from one estate or dis- 

 trict to another. The shaking of the trees also disseminates 

 spores, and they are driven from fallen leaves to the trees. These 

 spores, scattered on the foliage, become washed down to the lower 

 surface and germinate as before, provided the atmosphere, &c., be 

 sufficiently moist. 



5. — No special predisposition on the part of the coffee is 

 required for its infection, and no other conditions are necessary to 

 the spore than moisture and the presence of aii', &c., as with any 

 germinating seed. 



6. — The spores are in such countless numbers, germinate so 

 rapidly, and some of them so easily escape the action of even the 

 most efficacious remedies, that no good and lasting results can be 

 obtained from external applications unless the sources of 

 reinfection be removed. No attempts to combat the disease 

 by passing ingredients into the tree have shown any trace 

 of success : the mycelium cannot be attacked after it has entered 

 the leaf. 



7. — Diseased leaves should be collected and destroyed, and 

 every means possible employed to prevent the ingress of winds. 

 Cultivation should be directed to these ends, and the j)runing and 

 manuring, as far as possible, arranged so that large masses of 

 young foliage are as seldom as possible exposed as a surface of 

 food material for the spores at those times when they are most 

 blo^vn about, as at the bursts of the monsoons. In cases where 

 the disease is threatening to denude the trees of leaves at the 

 critical period when crop is ripening up, there can belittle question 

 of the use of lime, unless weightier considerations, based on the 

 results of experience with that particular soil, forbid it. 



8. — Manure can in no sense be properly looked upon as a cure 

 for the disease. In so far as it enables a tree to clothe itself with 

 dense foliage, the tree may be able to afford the sacrifice of a 

 number of its leaves to the fungus ; but the well-fed mycelium will 

 in such cases produce more spores in xDroportion, and these may be 

 the more readily distributed, and germinate on other leaves, and 

 so the stock of fungus be actually increased. Nevertheless, careful 



