December, 1890. 
211 
O R CH PiR D 
GARDEN \ 
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^ for two-thirds their length, beyond which 
they are transparent. 
Within the central body is a single, very 
delicate sac (see as, figure 350) which, in 
turn, encloses eight ovoid or oblong spores — 
the ascospores or sporidia. These ascospores, 
thus securely wrapped, first by the strong 
walls of the perithecium, then by the thin- 
ner membrane of th»* sac orascus, are well 
protected from injury by accident or severe 
winter weather, through which season they 
are designed to pass. In spring or early 
summer the ascospores escape from the 
case-like perithecium by the natural decay 
of the latter, and happening to be carried 
to some young plum or cherry leaf they 
start a new growth of the parasite. 
As the entire plant body of this fungus is 
exposed to any direct application made to 
destroy it, the treatment is a comparatively 
simple mattter. Treatment should be made 
before the formation of the mature fruits as 
these are far less easily destroyed than the 
simple mycelium or conidia. The flowers 
of sulphur, properly applied, will destroy 
these. A good effective liquid remedy for 
this, as well as other Powdery Mildews, is 
a solution of liver of sulphur (sulphuret of 
potassium), one half ounce to the gallon of 
water. This solution ought to be used as 
soon as prepared, and it is best applied 
warm. ^ 
Treatment of Anthracnose of the Vine. 
In “Le Progres Agricole" for Oct. 26. 1890, 
we find the following preparation recom- 
mended for the treatment of Anthracnose: 
Water 3 gals. 
Sulphate of Iron 7 lbs. 
Sulphate of Copper 2 lbs. 
Sulphuric acid 1 gill. 
This is to be applied to the vines two or 
three weeks before vegetation starts in the 
spring. 
A powder v\ hich is highly recommended 
^ as a remedy for anthracnose, is prepared 
by mixing in equal parts Portland cement 
and sn bli mated sulphur, to which is added 
one to five per cent, of finely powdered sul- 
phate of copper. This compound should be 
applied just alter rains or when the dew is 
on, in order that it may adhere well. Three 
applications are recommended, to be made 
during the growing season. 
Rose-leaf Blight. 
(Cercospora Rnscecnla). 
Rose-leaf blight, or Leaf-spot of the Rose 
as it has been named, is caused by a para- 
sitic fungus of the genus Cercospora. This 
genus is a very large one — Saccardo de- 
scribes 233 species— and its members are 
found upon a great variety of plants, 
almost always attacking the leaves, the 
tissues of w hich they invade and destroy. 
Their presence is manifested by the death 
and browning of the leaf-tissues around the 
points of infection, imparting to the leaves 
* a more or less spotted and diseased appear- 
ance. The fungus growth in the interior 
of leaves comes primarily from spores 
which have fallen upon their surfaces and 
there germinated. The delicate germ-tubes 
which these spores emit, quickly penetrate 
the skin or epidermis, and in the tissues 
which underly this they find a soil well 
suited for their further development. 
After a certain period, when the fungus 
has gained sufficient vigor for the produc- 
tion of its fruit — the spores — special centres 
of growth are formed just underneath the 
cuticle and from these spring little tufts of 
branches, called hyphee, which, breaking 
through the epidermis of the leaf, ap- 
pear upon the 
outside and bear 
upon the>r sum- 
mits the slender 
and more or less 
elongated spores, 
called here c.on- 
idia. Such a tuft 
of conidia-bear- 
ing hyphae is 
shown in our il- 
Fig. 356, Hyphae and conidia, , ,. „ 
of the fungus of Rose-leaf Blight, mstration qJ j-[ )e 
Cercospora of the Rose, Fig. 356. 
If the reader will take the trouble to 
compare our illustrations in previous num- 
bers of the Orchard & Garden, of Black- 
spot of the rose and Powdery Mildew of the 
rose, with those given here of Rose-leaf 
Blight, he cannot fail to notice how very 
different the last named is from either of 
the former, particularly in its microscopical 
characters. Sometimes there is a slight 
resemblance between the external charac- 
ters of Black-spot and our Leaf-blight and 
the two might occasionally be confounded 
by a casual oi server, but there is a striking 
and unmistakable difference in the fungi 
causing these dis- 
eases, well shown in 
our illustrations (see 
figure 26 ? in the March 
number and figure 356 
of this issue). The 
spots caused by the 
blight fungus are dark 
brown, sometimes 
grayish in the ceutre, 
with well defined, dark 
red borders. They vary 
in size from less than 
a twelfth of an inch 
to one-fourth of an 
inch or more in di- 
ameter. A diseased leaflet is show n in fig- 
ure 555. 
Rose-leaf Blight, while perhaps no less 
widely distributed than Black-spot, is rarely 
so destructive. It is found attacking both 
our wild and cultivated roses, but of the 
latter it seems to prefer the more hardy and 
especially the climbing varieties. Such ha.' 
been our observation the past season. Under 
conditions generally unfavorable to the 
growth and health of the plams ihe foliage 
is very likely to be severely attacked oy 
this parasite, and a premature falling of 
the leaves results. 
Plants situated where they will have an 
abundance of air and light, and which are 
well pruned and otherwise properly cared 
for, will rarely show any signs of this leaf- 
blight disease. 
Fig. 355. Leaflet of rose 
attacked by Leaf-blight. 
Beet-leaf Blight. 
(Cercospora belicola.) 
Every one must 
disease which we 
name here Beet- 
leaf Blight. It is 
common both in 
this country and 
in Europe ; during 
the later months 
of the season one 
can hardly pass 
through field of 
beets, or even a 
garden patch, with 
out seeing at least 
a few leaves at- 
tacked by the 
blight, and occa- 
sionallv they will 
find a plat in which 
nearly every plant 
will have one or 
more of its leaves 
attacked. When 
thus severest must 
very materially af- 
fect the crop if not in the size of the roots, cer- 
tainly in the amount of food material which 
they contain. Where beets are grown for 
the making of sugar this disease is to be re- 
garded with apprehension as it will large- 
ly diminish the amount of this product. 
The fungus causing this blight is a Cer- 
cospora, very similar in its habits and char- 
acters to the Cer- 
cospora of the rose, 
differing chiefly in 
its conidia which 
is very much long- 
er, more slender 
and divided into 
many cells by fre- 
quent cross parti- 
tions or septa, see 
figure 354. The dis- 
eased leaves are 
lliickly covered 
with small round- 
ish spots one-six- 
teenth to one- 
eightli of an inch 
in diameter, of a 
pale or grayish col- 
or bordered by a 
narrow ring of 
dark red. Within 
this ring the leaf 
cel's are dead and 
the tissue becomes 
thin and dry. The 
Fig. 354. substance o f the 
leaves, thus weakened, is liable to break 
away here and there, particularly near the 
margin, so that the foliage often presents a 
broken and ragged appearance. 
We do not know of any efforts or experi- 
ments which have been made with the view 
of preventing or checking this disease. 
Clean, open culture, giving the plants 
plenty of r< om. in well-drained soil, will 
prevent its doing serious damage. All dis- 
I eased leaves should be destroyed. 
