SEi>^ 1, 1899.] THE THOPICAL 
AGRICULTURIST. 
Permanganate of potash solution— Sulphur— Lime— 
Besin wash — Jensen's hot water treatment for wheat 
and oat smut — Paraffin — Formalin — Lysol — Kesin com- 
pound — Fumigation with hydrocyanic acid gas — Steri- 
lising soil — Poisonous properties of fungicides. 
After this we are treated to some " Eco- 
nomic Considerations" on "Statistics relating 
to losses caused by grain rust in Prussia- 
loss through rust of wheat in Australia- 
destruction of vineyards in the United 
States caused by fungi "; and to an account 
of " Various methods of spraying— spraying 
apparatus"; and still again to "Descriptions, 
with preventive and curative methods, of the 
various kinds of parasitic fungi attacking 
plants of economic importance." Various 
useful indexes conclude the volume. 
But now, in regard to the two products 
and their diseases in which Ceylon is at 
this time most concerned, namely tea and 
cacao, we repi'oduce all that Mr. Massee has 
to say even at the risk of some repetition. 
Here are three pests of tea : — 
"blister blight" op tea plant. 
(Exobasidiuvi vexajis, Massee.) 
Dr. Watt, who investigated the pests and bligbts of 
the tea plant in Assam under instructions from the 
Government of India, says of the preseat parasite ; 
' One of the very worst blights on 'tea is known lo the 
planters aa Blister blight. I have seen hundreds of 
acres completely ruined by it.' 
The fungus attacks the leaves, first appearing as a 
minute pink spot, which continues to inci.case ia size : 
the under surface of the leaf at this point becomes 
depressed, forming a circular pit, a corresponding 
bulging out appea'riug on the under surface of the 
leaf at the same point. Several of these warts of 
blisters frequently form on a leaf. The convex surface 
of the blister eventually presents a minutely velvety 
or woolly appearance, due to the formation of 
the fruit of the Fungus on the surface of the 
blister. The first fruic consists of small, one- 
septate conidia, which often commence germination 
in situ. These are followed by basidia> usually bear- 
ing two spores each. Sometimes fruit is also pro- 
duced on the concave side of the blister. 
When the disease has gained a foothold on the 
leaves, it also frequently attacks young shoots. 
Preventivb Means.— Dr. Watt states that the 
disease ' invaribly appears on tea that has not been 
pruned in the autumn. About April it extends to the 
pruned tea, which has by then come ir to leaf.' As 
to whether it would not be wise under the circum- 
stances to prune all plants, lack of practical know- 
ledge prevents me saying; however, the statement 
suggests that the mycelium is perennial in the 
branches, and produces the first crop of spores the 
following season, which are carried by wind to the 
pruned trees. In addition to collecting and burning 
diseased leaves, it is absolutely necessary to cut otf 
all diseased branches. 
Ascertain that the fungus is not also present on wild 
plants in the neighbourhood of the tea plantations, 
Watt, The Pests and Blights of the Tea Plant, p. 419, 
Massee, Kew Bulletin, 1898, p. 109, figs. 
" GREY BLIGHT " OP TEA PLANT. 
(Pestalozzia guepini, Desmaz.) 
Said by Dr. Watt to be one of the most destructive 
and dangerous of parasitic fungi to which the tea 
plant is liable. It occurs in Assam ac d Cachar, and 
probably in all the tea districts of India, also in 
Ceylon. The disease first appears as minute, 
brownish-grey spots on the upper siirface of the 
leaves. These spots gradually increase in size and 
coalesce, forming large, irregular blotches, which 
finally become grey and sprinkled with minute black 
points, the fruit of the fungus. During the increase 
iu size the blotches are often bordered by a dark. 
Slightly raised line. Diseased leaves are not at all 
blistered or swollen ; in fact the grey patches are 
thinner than the uninjured portion of the leaf, owing 
to collapse o£ the tifs^ues. 
Dr. Watt states that the disease commences for the 
most part on one side of a bush, very often on the 
same side of all the bushes over an effected plot — a 
circumstance that may be taken as indicative of the 
germs having been wind-conveyed. 
In addition to growing on the tea plant, Pestalozzia 
gtiepiiti also occurs as a parasite on other species of 
Camellia and on Bhododendron in India; in Europe it 
is not uncommon on cultivated camellias and rhodo- 
dendrons. In the United States it also occurs on 
introduced species of Camellia and Citrus, from 
whence it possibly passed on to the native Magnolia. 
Finally it is known to occur on indigenous plants 
{Niphoblous) in New Zealand, and on Alphitonia in 
Queensland. 
Preventive Means. — The remarks I offered in the 
Keir Bulletin are repeated here. If the diseased leaves 
were collected with the amount of care and intelli- 
gence exercised iu collecting sound leaves, and burned 
at once after being collected, the disease would soon 
be stamped out, as the mycelium of the fungus is not 
perennial in the tea plant ; consequently infection 
and a reiurreuce of the parasite depends entirely on 
inoculation by the numerous conidia or reproductive 
bodies of the fungus present on diseased leaves. 
Kemembering the very different kinds of plants on 
which the fungus is known to be parasitic, it is very 
probable that it also occurs on wild plants growing in 
the vicinity of the tea-gardens. If such proves to be 
the case, all such plants should be removed if practi- 
cable, as the conidia of fungi are carried considerable 
distances by wind, birds, and insects, and no amount 
of attention in the way of removing the parasite from 
the tea plants would avail if the supply of conidia 
requisite for inoculating the tea plants were formed 
on other plants growing in the neighbourhood. 
Watt, The Pests and Blights of the Tea Plant. 
Massee, Kcw Bulletin, 1898, p. 106, figs. 
thread BLIGHT OF TEA PLANT. 
(Stilbum nnnum, Massee.) 
Indian tea-planters have known this most destruc* 
tive fungus for at least the last thirty years. Tbe 
name ' thread blight ' is given on account of the very 
thin strands or films of white mycelium that are 
firmly attached to the branches and under snrface of 
the leaves of the tea plant. The mycelium also runs 
under the snrface of the branches, living in the , 
tissues of the bark, and coming to the surface here 
and there to spread over the outside of the leaves and 
twigs. 
GThe fruit only appears to be formed on very old, 
rotten branches that have fallen to the ground and be- 
come decayed, and resembles pins in miniature — a 
very slender stem and a round head, the whole not 
half a line high. Repeated observation proves the 
fruit to be very rare, and infection from spores may be 
left out of consideration, except in the case of reclaimed 
ground, where the trees have been neglected for' 
some time. 
The amount of evidence forthcoming seems to 
suggest that the mycelium travels underground) and 
first attacks the root, afterwards passing up the stem, 
either externally or internally, always finally coming 
to the surface. 
Preventive Means. — It seems to be generally 
admitted that thread blight is common in the jungle on 
various plants ; and to prevent its spread to the tea 
plants, narrow trenches should be kept open. These 
need not be very deep, as underground mycelium rona 
near the surface. By similar means, diseased patches 
in the plats should be isolated. Prnnings should 
be burned and not buried, as each buried mass may 
prove a centre of infection. If quicklime is available, 
and not in other respects injurious to the tea plant, 
a shallow trench should be made round the stem, 
filled with lime, or lime mixed with sulphur, and 
covered over with soil. 
Spraying with Bordeaux mixture or with potassium 
sulphide would check the external spread of the 
mycelium on the plant. 
Watt, Pests and Blights of the Tea Plant, p.'43a. • 
Cunningham, Scientific Mem. Med. Officers' of Army of 
/neiia, pt. X. p. 20. ; 
Massee, Kwi Bulletin, 1898, p. 111, figs, 
