Jltne 1, 1899.] THE TROPICAL AGRICULTURIST. 
82.3 
REPORT ON COFFEE LEAF DISEASE 
IN COORG. 
[Including Deschiption op Coobg; Culti- 
vation OF Coffee — Shade, Weeding, Man- 
UBBS,— Si;ED, Vabieeies, Hybridsing.] 
BY MB. JOHN CAMERON f.l.s. 
{Concluded from page 7oS). 
COFFEE PESTS. 
"W« should be happy that it is an industry that 
involves a certain amount of trouble. Otherwise it 
would be taken cut of our hands altogether." Such 
ia the pithy and hopeful remark made by an able 
and experienced planter on the occasion of the 
last Conference of the United Planters' Association 
at Bangalore. A statement of this sort indicates 
the true energy which underlies all the actions of 
Briti»h enterprise. 
In the latter case obstacles are of litlle moment, 
and may be of real advantage in keeping out the 
faint-hearted. The same spirit prevails in Co irg, al- 
though borer, leaf-rot, leaf -disease, bug and other pests 
have each done their best to diminish the planters, 
profits— uncertain crops and foreign competition being 
a futher tax on his patience. Leaf-disease, whi< h is 
most dreaded, wa<! not very prevalent or any of the 
estates visited. llennUio. Vastatrix, th« fungoid 
parasite which causes leaf disease, by partially cr 
wholly disorganising the functions of the leaf, made 
its appearances in Coorg in the early seventies after 
committing great havoc in the planting districts of 
Ceylon. The peculiarity of the fungus is that it 
persistently [ollowa the coffee bush all over the 
country and is more cr less prevalent whererer 
coffee is grown. A virulent attack on the experimen- 
tal plot in the Gardens (Lai Bagh), has just b«en 
temporarily checked by burning every infected leaf 
and coating the ground with a thick layer of 
quicklime. 
Combustion, whether active or passive, is the 
natural enemy of f nngoid organisms ; and when Mr. 
Marshall Ward recommended burning everything 
that could be burnt with safety on the estate, he 
gave good advice. During the pruning and wood- 
ripening season, tons of le&ves and twigs could be 
disposed of in this way, although it is admitted that 
a coffee zone such as the " Bamboo" provides 
but little space for kindling fires. It is the annual 
recurrence of the scourge which makes it so disas- 
trous, and anything that would harass it or deprive 
it of nourishment at critical periods wouli have the 
effect of saving the host to a large extent. 
Spraying operations were observed at Hallery, where 
Mr. Sprott thinks he has gained some advantage over 
the fungus. The mixture, in use is 3 lbs. lulphate of 
copper and the same quantity of lime dissolved in 25 
gallons of water. 
The Califoinian remedies for fungoid and other 
pesta are given at the close ef this paragraph. 
The lAfe-hislonj of 
J/eiiiileia Vasfalrix vras thoroughly worked out by 
Mr. Marshall Ward in 18S1, and readers cannot do 
better than refer to his acientitic reports, written for 
the Ceylon Government on the subject about that time. 
The Director of Kew Gardens gave it as his opinion, 
in 1S92, that Hemileia Vanlatyix is a species endemic to 
the Island of Ceylon. Thisgreat authority futher adds, 
" Like thousands of other microscopic leaf fuBgis, 
itpiobably maintained its existence in an unconspicu- 
ous manner in some native Rubiaceous plant (i. e., 
belonging to the same family as the coffee). It was 
probably only by a kind of accident tliat about 1869 it 
feund a suitable host in cultivated coffee, and thus 
was euab'ed to develop itsfilf on a scale which speeilily 
made it a scourge." Since the latter date, whea 
first ob.ser\ei, tlie parasite has followed its host unre- 
mittingly to every coffee region of the old word. 
Change of food would poasibly arrest its progress 
sooner than anything. Slight constitutional change in 
the liOHt miyht bring this about, and the process of 
liybiidisiug would be of much value if it secured even 
partial immunity to the coffee plant from the attack 
of llemileia. That such a thing is possible has 
already been proved by the rising of certain varieties 
of potato which are wholly immune from Phytrphthora 
infestans, the most hurtful fungoid parasite of that 
esculent. 
THE BOEEB. 
The next pest to be briefly considered is the borer 
{Xylotrechus quadrupes^, which is indigenous to the 
country. In fict, there are several borers, and the 
remedies here recommended will app'y to them all. 
It is only in the more exp> sed parts of South Coorg 
that the ravages of these insects ire much f' It, and 
even there the conditions are far more hopeful than 
they were thirty years ago. At th-n time the whole- 
sale "estrnotion of forest trees, accompanied by undue 
exposure and indifferent cultivation, aggravated the 
attack and was the indirect cause of enormous loss to 
the planter. But it is now understood that sufficient 
shade and moisture, supplemented by good tillage, 
are conditions inimical to the spread of borer. The 
rush for extension which prevailed a few years ago, 
when prices went up, must be held responsible to a 
large extent for the maintenance, it not increase, 
of coffee pests. A large area (in fragments here and 
there) of unsuitable land was placed under cultivation, 
and by a process of forcing in some cases and compa- 
rative neglect in others it was hoped to increase the 
average ontturn of bean. But a cycle of dry seasons 
shortly followed, and the new openings were mostly 
foun i to be infested with leaf disease and borer, which 
rapidly spread to healthy tracts that had not suffered 
before to the same extent. The occupation of such 
lands by coffee is therefore a standing danger to the 
whole local industry. I can imagine nothing more 
disheartening to a really good planter than to 
have neighbours who will act recklessly in the 
selection and treatment of land, to the jeo- 
pardy of the whole community. In addition to 
depth of soil, moisture, and shade, the presence of 
numbers of insectivorous birds is recommended for 
the extinction of borer. Of these, woodpeckers, jays, 
thrushes, mynas, hoopoos, sparrows, larks, jungle 
fowl, the crow pheasant and many others are insect 
eaters. When the larvas can be got at, which ia not 
very frequently, the direct aplication of neem oil 
is the surest remedy. If poured into the holes and 
tuunels caused by the insect, it will either bring out 
the latter quickly or cause its death inside. In this 
connection 1 may mention that neem oilcake, which 
is manufactured at Hunsur, might have a remedial 
effect if applied to land affected by borer. Rubbing 
the coffee stem at intervals with the oil would be a 
good practice. 
LEAT ROT. 
PfUicuIaria Koleroga, or "leaf-rot," is an epiphytal 
fungus which envelopes the coffee leaf during the 
monsoon and subsequently kills it. Continuous or 
heavy rainfall, density of shade, drip, and stagnation 
of drainage, are the causes of this fungoid growth. 
A modification of the above conditions with the use of 
fire to destroy all affected leaves, and the application of 
flowers of sulphur in the early stage? of attack are 
the best known remedies. Bordeaux mixture and 
other fungicides should also be tried. For the eradi- 
cation of bug and scale insects, the importation of 
a useful species of lady-bird is under trial. The brown 
Ecale-insect,* Dactyhpins adonidum, is prevalent on 
many of the jungle trees, where it is farined by ants 
for the secretion known as "honey dew." It if 
usually accompanied by the black fungus Tii$ponum 
Gardneri, Berk, Kerosine emulsion is a good remedy 
for these pests. 
REMEDIES FOR PLANT DISEASES. 
Extract from Spraying Calendar, Central Experi- 
Farm, Ottawa. 
•The 'Brown scale insect' is Lteaiiium eoffea 
Dacti/hpiits «(^»(Wi(m is the so-called 'Mealy bug" — 
El). T.A. 
