^90 
THE TROPICAL 
AGRICUr.rURIST. [June 2, 1902. 
Two cases o£ tisa strack by lightning weve examined, 
and from the tacis observed by the plaiueis si u(3ing 
theiu.Hnd ihf - vpe vnin s luidi-i tli^ nuc-.io . opr of botii 
Stem and k-a-VvS, ilitjie wiis i;u . uub. iliciujiiiy 
Wa& dut to ihe pa-sage ut ..u elec;; i-.u c;u )c-:jt along the 
ground ocoupitd by the loot.; of bepauis. I iiave 
investigated a sunilai- case in Euglaod, of elms in 
Leicestershire stru> k by iightmug, whtre the shrubs 
and other pljuts ntar the elm trees were damaged 
along the tr ck of the currc-iit. 
In the Oylou case a urevillea tree was struck and 
the tea bushe"^ immediately suirouuding were damaged. 
In such cases of aocdeulal injury it is pot&ible by the 
help of some cattle or olher suitable manure to prevent 
the plants dying, if they are observea and treated soou 
after the shock. 
It is often not easy to say definitely that the lack of 
health of a plant is due to environmental causes, 
especially without careful observations of the circums- 
tances of the case, bat these are evils that ihe planter 
knows well and knowa the way to cure— by removiiig 
the conditions. In my experience the planter generally 
does recognize environmental diseases, though, as is 
only to be expected, he is iuclined lo attribute the first 
eliects of certain root diseases which are caused by 
fungi to such causes. If, however, bushes in nearly 
similar condition.s, and apparently originally as vigo- 
rous, are " shuck,'' some root disease of a fungal nature 
may legitimately be suspected. In any case of doubt 
the roots shou d be examined, and if a fungus is found, 
or if signs of it are seen, such as discolouration and 
decay of the root tissues, the whole should be destroyed 
by burning, and the soil around limed. 
The planter who will suffer least fiom diseases in his 
cultivations must exercise the same observation and 
use the same care to keep his plants in health aa he 
does for his horse or his dog. Without a kuowledge of 
the anatomy and physiology of animals, he is yet 
able to prevent and cure many of the diesases of his 
domestic animals, and so in the case of his plants ; 
whatever kind they are he may use preventive and 
curative means as soon as he notices any disease affect- 
ing his estate. 
LEAP DISEASES OF TEA- 
Tea has been throughout the year less affected than 
last year by leaf diseases. In the case of Gray Blight 
(Pestaloxzia Gliepini,) it has been sent to me from 
almost every tea district in the Island, and therefore 
seems to have spread across vv'ide aieas. Though I 
have since my airival in the Islaaa exiimined an im- 
mense numoei' of diseased leaves from jungle and 
other plants said to be affected by thid leaf disease, 
I have in no case found the fungus to be growing on 
any other plant. lu many cases badly atfeoted tea is 
surrounded on one or more sides by jungle or scrub 
and though vast numbers of spores must have lit upon 
the leaves of plants growiug there, no blighted leaves 
with this paticular fungus iiave been found. 
Au interesLing cace of the method of distribution of 
spores was observed on au estate in a vi/aii district. On 
the windwaid side of a n,irrow strip of jungle, at the 
brow of a hill, was a bad y blighted field of tea ; a road 
s me 20 or 30 feet wide had been cut through the 
jungle, and Oii the leeward side was a field of tea, 
only biighied on the buohes wihch were opposite the 
opening through the wood. This p .ints to the pro- 
tection of tea in some cases by means of wind or other 
belts of trees The whole question of spore distribution 
is one of rather a com(;li;x nature ; it is however one of 
great importance from an economic point of vievv', and 
the experiments initiated during the year wilh a view 
of gaining a definite knov/leUge of coiiditious under 
which spores are distributed will, it is to be hoped, 
lead to measures l.kely to prevent or hinder the 
spreading of the spores of leaf diseases. 
SI'OI!i; »lyTRIliUXION EXPERIMENTS. 
The experimental " tabernacle.), " whicli are built of 
jute hossian and are 45 feet long by 8 feet broad, 
eaclosiug thirty tea bushes in two rows of fifteen, are 
9 feet high, and are placed at right angles to the pre- 
vailing winds in certain selected distiicts at various 
cleVcitious and climates. Tney are open to the bky, 
and the tea in the enclosure is ae neaily as possible 
under the same conditions as that outside. The ob- 
servations already made in the tjbeinacle where the 
tea has already begun to bear leaves have yielded 
valuable information, and when the whole of th.-ee en- 
closures at varying heights i,nd climates are under ob- 
servation many data of importance will be gained. 
All the tea both in the tabernacle and the sunound- 
iag field is pruned, and when the field Ims come into 
bearing all leaves on bushes inside ihc enclosure and 
around it which show any sign of disease are examined 
microscopically and the disease determined. The out- 
break of disease on either side cf the tabernacle is also 
observed and recorded in the same way. By thus ob- 
seiviug at close and regular intervals the same thirty 
bushes a knowledge is gained of the behaviour of 
different bushes to disense. One question of much in- 
terest as regards tea with gray Blight and other leaf 
diseases, viz., whether the weakly bushes are more or 
less liable 1 3 attack than more vigorous plants, and as 
to how they re-act to the disease, can here be studied 
carefully. The data are to be collected at the different 
stations by the superintendents of the estates selecte d 
and tlie leaves forwarded to me for examination. 1 
also hope to personally inspect them at eert-^in inter- 
vals. These geutleinen have most kindly taken a 
great iuteiest in the investigation, and their valuable 
help ill this matter will, I hupe, be repaid by an ad- 
vance in our knowledge of the whole question. The 
following is the schedule to be returned after each 
plucking, which will explain to those interested the 
modus oiierandi of tho investigation : — 
TEA BLIGHT INVESTIGATION. 
The Mycologist, w hile wishing lo reduce the amount 
of trouble taken by each observer, will be glad to re- 
ceive as complete answer as possible. If the terms sug 
gested in the footnotes only are used the com- 
parison of the observations at the different stations will 
he simplified. When convenient the returns should be 
sent to Peradeniya next day, so that the diseased 
leaves can be examined with little delay. All the 
diseased leaves should be sent, unless too bulky, when 
they should be weighed and the weight sent, with as 
many of the leaves as possible. 
The tabernacle should be kept c osed and only the 
Kangany or Cooly who is to pluck the bushes admitted. 
Name of Estate 
Date of plucking ■ 
Weather Conditions * 
Wind t 
"Weight of leaf plucked from enclosed ) 
bushes (green) J 
Approxim.ite number cf bushes from ( 
when the diseased leaves came \ 
Conoition of nearest bushes on North ) 
side of tabernacle j 
Condition of nearest bushes on South \ 
side of tabernacle J 
Does the flush on enclosed bushes ( 
fairly agree with the rest of the field ? j' 
Remarks or observations: — 
* "Very wet," lainy, " "no rain," "no sun,'' 
" sunny, " '• hot sun. " 
t "No wind, " "little wind," "variable," "con- 
stant wind, " " stiong wind. " 
GRAY BLIGHT ON YOUNG SHOOTS. 
As was mentioned in my last annual report, a cir- 
cumstance v^ith regard to Uiay Blight, which calls for 
attention, has been again more than once brought to 
my notice. It is the fact that the fungus grows in 
some leaves so vigoiously that it penetrates back 
through the leaf-staik to the young shoot. In these 
cases It is able to grow longer than it can do in the 
leaf, which usually fulls off the bosh when entirely 
killed by the fungu.j and consequently it ia on these 
older parts that 1 have at last discovered the perfect 
