388 
THE TROPICAL AGRICULTURIST. [Dec. 2, 1901. 
wake up one day to the fact that Java has 
Sven them the "go by" ui that produot, 
as she has torrnerly done m cinchona and m 
•1 lesser degree, in coftae. These Dutch 
planters travel slow, but sure ! I am sure 
it is to none of our advantages to see more 
tB-s,-anywliere. [But what about local con- 
duinstion ?-Ed. T.A.] I wonder, too. if that 
ULTRA-CLEANLINESS FaOM WEED3 
that every Ceylon planter I have ever met 
seems to think a ^^simqiumon of good 
tea cultivation, has anything to do with the 
increase in both quality and quantity of 
diseases which tea in Ceylon seems more 
snbiect to than here . T,,r, T 
A^Eter nearly 10 years P'^\"ti"S 
am prepared to bet my bottom dollar that 
fZ,ty tea, jnst as is tne case with young 
cinchona, g^ows stronger and ^^^^ }^ 
amon'^st weeds. Sometimes old tea seem, to 
do so too -of the right sort of course-not 
b id grasses, which should be regularly forked 
out in my opinio-n, and the tertihsing weeds 
sometimes left though not to a too luxuriant 
arount and then dug in. Young tea on my 
estate and on others I have to do witb, 
seems to me to revel in such conditions - 
fmTsurely it is only following " N^vtnre ' 
that it should do so -for the young stems and 
crowns of the roots are all the tune pro- 
tected from excesses of sun, wind, wash and 
all forms of exposure and in the warm season 
kept cool and regularly re-dewed, 
I saw really bad 
" GREY BLIGHT" 
for the first time in my life in Java last 
week and that was on the young tea estate 
Tf a Ceylon co-Director of mine, now resident 
ia Java: on whose estate there is not a 
sino-le weed of any sort to be seen. It is a 
S'ct example of a clean tea estate and 
the weeding cost per bouw is very cheap, but 
^„ i^nre or less 100 bouws the bushes 
were baJe from the joint attack of Helopeltis 
Tnd this awful Grey Blight, and at that rate 
the deeding cost cannot be very c-ap Per 
lb even if it is per bouw! Can it not oe 
Ifosslble the young tea would have been 
Tardie. and better able to withs and these 
.ittpoks if let to run a bit wild at tirst 
Sn tWs estate I am sure such is the case 
But this is all treason to write to 
aUeyloaman, I know ! So I w ill refrain. 
LECTURE ON TEA BLIGHTS. 
By J. B. C.VRRUTEIER3, ESQ , P.L.S. 
Hnmint' to Ambegatnuwa to talk aboat the disaasea 
of tea is "somewhat like taking coals to Newcastle as 
voa? Chairman has obsecved so carefully knows 
well the nature and effects of your common blights 
Still you are already interested in them by means of 
Mr OoUett, you may be, more wiUing to hear what I 
^ wVmTy'for practical purposes group the diseases 
which tea and oiher cultivated plants are subject to 
as environmental and specific. Environmental are 
those diseases which are due to phyaioa conditions 
iniurious to the vigorous growth of the plant such as 
IrouKht excess of Water ao the roots, continuous and 
„owerf'il Wind, absence of ntitritive substances in 
rwe soil&c. These are evils which the planter knows 
* LI aadhe knows the way to cure the plant suffering 
fiooi 9> dieeaae of this ordeMemove the ooaditioaa 
if DJssible an! tha pl^nt recovers if it is not too late. 
While mjritionin? this I m ly siv that it would be an 
a iv:iQti;<3 ifpla isers w juid rn iks fis-nsslves acquiintii 
with tUs usuil sympVjiin in the leiE of somj of t'lese 
enviraa'nental di39i,333. I£ hi eia do it in no other way 
let him select a bash of no greit value, somswhera 
tint he cm convocieutly exiiii'ns eicti div, and 
d t,m ige tha root i by severely outtiug them, so as to 
imitate to f^ome extent the pliysio.ogicil efficts of 
drought, fie will then have aa objeco lesson of a tea 
b ish puffijiing from an environmental disease — « 
disease which he is able himself to deal with quite as 
wall as if mt b Hter thaa a plint pithologist. I 
have frequsatly Bint to me spscimeas of tea leaves 
and the leives of other cultivated pliuts, which are 
merely discoloured and pirtially dead from the effects 
ofj drought or " wet feit." I; is n >t alwiys eisyto 
siy without a m^scroscopical es.imtQation it this is 
80; but in m tny cases an acq laintuaace with the 
efficts caused by drought, wiud etc., would lead to 
the planter being himself able to remedy the evil. 
In the other class — the specific diseases are mora 
cominon perhaps and more diffi jult to remedy or cure. 
They are diseases due to the attacks of a foreign 
orgmism oa the plant an insect, fungus or bacterium. 
It is the duty of all to euJeavouc by observation 
and experiment to get all the knowledge possible of 
these enemies, so that we may bi able tj war in- 
telligently against them aud reduce the loss to the 
tea bush. It is important to remember that though 
the fungus or bacterium is called the '• cause '' of 
the disease yet it is ouly one of the causes, strictly 
spe.ikiug. Sneh disease are the effect of a number 
of factors working together. In the case of leaf 
diseases on tea we can see what conditions in addi- 
tion to the presence of the spores of fungi are needful. 
We have in tea in Ceylon some specific leaf diseases, 
of which grey blight (Pestaiozzia rjuepiui) is the 
most widely distributed and best known; and as it 
is known so well a great many leaves which are 
dying owing to environmental diseases, and other 
specific diseases not gray blight, are attributed to it. 
Grey blight is due to the pce-sence of the growing 
mycelium of Pestaloz~.ia in the leaf tissues, bat the 
attack ot blight in any spot on the leaf canuot take 
place unless when the spore lights on the under 
surface of the leaf when there is moisture in the at- 
mosphere to allow it to germinate. Here in Amba- 
gamuwa you have exceptionally favour^ible conditions 
for the germination of spores of fungi. Your days in 
which there is a moist atmosphere sufficient for spores 
to germinate are in a tremendous proportion to your 
anti-fungus growing days, i. e., with dry atmosphere. 
The spore of the grey blight lights on the under 
surface of the leaf — as in the diagram — and in a 
moist air — a very damp atmosphere is not needed. 
I have grown the spores of grey blight on dry glass 
plates in the evening and early morning of an average 
day at Peradeniya when the air was not, either by 
the wet and dry bulb thermometor or to dub's own 
senses, dimper than usual. The spore grows along 
the surface of the leaf until it reaches a breathing 
hole or stoma in the leaf, of which there are large 
quantities on the under surface of the tea or other 
leaves. When it reaches one of these holes it 
tarns in and grows in the space between the 
ojUs of the leaf. After it has grown for some 
tima ia these spaces it penetrates the cells and kills 
them successively. The time taken to kill any defini'.e 
area of tissue in a leaf varies with the condition of the 
leaf, the moisture of the air, and other factors. In 
soma experiments of tea leaves I found that a dis- 
coloured patch about the size of a ten-cent piece was 
produced some time after the spore had been sown on 
the leaf. In one case a visible patch of this size was 
caused in 12 days, in another 19, and in a third in 2i 
days. It is important to keep in miud that the time of 
the visible signs of disease is not the same as th.i tima 
of the ontbreak of the disease or rather the origin Plan 
ters frequently say of tea diseases as well as others " a 
sudden otttbrealj— I kuow exactly whea it gocurred'' 
