August, 1889. 
162 
ORCHARD #£Sr% GARDEN 
t'ONUl'CTKI) BV PKOK. F. LAMSON SCRIBNER, 
Botanist, Experiment Station, Knoxville, Tknn. 
Plum Pockets, 
(Taphrina pruni.) 
This disease is due to the presence of a 
parasitic fungus which attacks the young 
fruit, and by its growth within their tissues 
causes the peculiar development of the lat- 
ter which finally results in the formations 
of the so-called ••pocket.’’ 
The “pockets" (^Fig. 1599) make their ap- 
pearance soon after the flowers have fallen, 
attain their full size and drop from the tree 
towards the middle or last of June. At 
first they are more or less globular in shape, 
but as they grow older they become oblong 
or oval and frequently more or less curved. 
They vary in size, but as a rule are from 1 
to 2 inches in length and from one half to 
one inch in diameter. When young they 
are nearly smooth and can be distinquislied 
from the healthy fruit by their pale yellow 
or reddish color. As they grow older the 
color changes to gray, the surface appear- 
ing as though it had been sprinkled with 
fine powder, and at the same time the 
‘•pockets’’ become 
wrinkled. Finally 
they turn black or 
dark brown, and rat- 
tle like bladders when 
brought in contact 
with any hard sub- 
stance. Sections 
through the diseased 
Fig. 159". fruit show that the 
walls are quite thick and that in place of 
a stone there is a large cavity filled with 
fungous threads and air. 
The fungus attacks the young branches 
and leaves, and when this occurs the in- 
jury is. of course, much greater than when 
the fruit alone is attacked. 
The disease never sweeps over the coun- 
try attacking all varieties of the plum alike, 
but, on the contrary, it often happens that 
a particular tree will bear nothing but 
“pockets” while adjacent trees of the same 
variety, grown under precisely the same 
conditions, show no traces of the disease 
whatever. As a rule a tree that has once 
borne a crop of “pockets,” seldom recovers, 
but continues with each succeeding year to 
produce a greater or less number of the 
malformations. 
All plums are more or less subject to the 
attacks of this parasite, but it is usually 
more abundant on the red and purple varie- 
ties. It occurs also on the wild red and the 
beach plums, and on the dwarf, the wild 
black, and the choke cherries. 
A microscopic examination of one of the 
diseased plums will show that the fungus 
oeeuring within the tissues consists of three 
parts, namely, 1 mycelium; 2 asci; 3 spores 
or reproductive bodies. The mycelium con- 
sists of colorless septate filaments. These 
are particularly abundant between the epi- 
dermis and cuticle where by repeated 
branching and interlacing they form a net- 
work which is not more than one cell deep. 
The threads forming this net-work are com- 
posed of very short cells which soon start 
an independent growth at right angles to 
the surface of the pocket, forming small 
cylinders standing close side by side but 
apparently unconnected (Fig. 1597). They 
at first cary the cuticle upon their ends but 
finally rupture it and appear on the surface. 
These bodies are the immature asci. [Fig. 
1596 shows these asci in a more advanced 
stage of growth, some of them being 
mature and containing spores.] Each 
“pocket” develops countless numbers of 
asci. and each ascus, as a rule, contains no 
less than 8 spores. 
The mycelium of the fungus is found in 
(he smaller branches in early spring be- 
fore the diseased fruit appears, which seems 
‘‘Plum Pockets.” Fig. 1599. 
to indicate that it may live from year to 
year in the tree itself; moreover the annual 
recurrence of (.lie “pockets” on the same 
tree furnishes additional proof of this fact. 
The treatment suggested is to remove 
and destroy all the “pockets” before they 
reach maturity, and cut back the branches 
so as to destroy all the parts which are like- 
ly to contain the mycelium of the fungus. 
— B. T. Galloway, in Annual Report of 
the U. S. Department of Agriculture for 
1888. 
Treatment of the Powdery Mildew of 
the Grape vine with Siilphuret of 
PotaaHinm. 
In the Report of the Department of Ag- 
riculture for 1888, page 333, is given the ex- 
perience of Mr. E. M. Hudson of Mobile Co. , 
Alabama, in treating the powdery mildew 
which attacked his European vines. Mr. H. 
says: “I commenced when the shoots were 
perhaps 6 to 8 inches long, with a solution 
of half an ounce (avoirdupois) of the liver 
of sulphur to one gallon of water. It was 
applied again when the grapes were begin- 
ning to color. The solution happened to be 
quite powerful enough and produced no in- 
jurious effects whatever on the the tender 
leaves and shoots. This treatment was ap- 
plied to two hundred vines (all marked) with 
absolute and unexceptional success, giving 
me a full crop of superb clusters of magni- 
ficent berries in every instance. About 34 
vines, interspersed- among those treated as 
above, and left wholly untreated, had their 
entire crop destroyed by the mildew. 
* * * 
“In preparing the solution, half an ounce 
of the liver of sulphur was dissolved in one 
pint of hot water; as soon as dissolved, the 
cold water (1 gal. less 1 pint) was poured 
with the hot solution and the whole imme- 
diately strained through a thick Osnaburg 
cloth into a tin can and closely stopped. It 
was then ready for use. 
On 250 vines 4 gallons of water with 2 oz. 
of liver of sulphur were used at each appli- 
cation. * * 
The applications were made with a Ver- 
morel Sprayer.” 

Tlie Powdery Mildews. 
The powdery mildews are of special in- 
terest to the horticulturist as they are wide- 
ly distributed and 
numerous, and at- 
tack a great varie- 
ty of plants. They 
are all surface- 
growing species, i. 
e., they grow en- 
tirely upon the 
surface o f the 
plants which they 
infest, and for this 
reason they are far 
more easily com- 
bated than other 
fungi which pene- 
trate more or less deeply into the tissues of 
the host. There is the Powdery Mildew of 
the Cherry, of the Rose, of the Pea, of the 
Gooseberry, of the Maple, of the Oak, of 
the Catalpa, of the Lilac, of Wheat, of the 
Grape, all, and many others besides, may 
be found in almost any county of the States 
East of the Mississippi. Nearly all appear 
as a white powdery or mealy substance 
upon the upper surface of the leaves. They 
are not confined to the foliage but may at- 
tack any of the growing or green parts. As 
soon as noticed they should be treated 
at once by applications of flowers of sul- 
phur or, better, with a solution of liver of 
sulphur (sulphuret of potassium), to J>.< 
oz. to the gallon of water. This is a cer- 
tain remedy for the powdery mildews, just 
as good as “liquid grison” and far more 
easily prepared. 
We propose to describe and illustrate 
some of these Powdery Mildews in future 
numbers of Orchard & Garden. 
Bekcham’s Pills cure bilious and nervous ills. 
AAA 
Fig. 1596. 
\ 
