144 
August, 1890. 
in April before the buds have started the 
trees should be most thoroughly sprayed 
with a strong solution of sulphate of iron 
or better, perhaps, a solution of sulphate of 
copper — one pound to eight or ten gallons 
of water. Then just before the blossoms 
appear spray again, this time using the 
amuioniacal solution of sulphate of copper 
or the modified eau celeste. At least two 
more sprayings should lx* made at intervals 
of from ten to fifteen days, and if the sea- 
son has been cold and wet, an additional 
spraying may be necessary. In orchards 
so badly infested as those referred to above, 
the labor of freeing them from the Fusi- 
cladium will be considerable and involve 
much patience and care, but the treatment 
is inexpensive, thoroughly practical and 
certain to prove successful; if not com- 
pletely so, at least to a degree sufficient to 
amply repay the undertaking. 
The Powdery Mildew of the Hose. 
In this vicinity one often sees rose bushes, 
particularly the new shoots, appearing as 
if covered with hoar frost, and on such 
plants the new leaves remain small, become 
more or less curled and look very much as 
though they had been frost-bitten. This 
whitened appearance and injured growth 
is due to the attacks of a fungus well known 
to the rose culturist and generally desig- 
nated by him as mildew. It is a fungus 
very closely related to the gooseberry mil- 
dew and has the same habit of growth. 
The surfaces of the affected parts are cov- 
ered with a more or less dense web-like or 
felt-like growth, which consists of a vast 
number of very fine and delicate threads 
(really slender tubes) that are closely inter- 
laced or woven together. On the older 
leaves this growth usually appears here and 
there as white blotches of varying size, but 
on the young leaves both surfaces are often 
completely covered, the fungus extending 
down the common leaf -stalk and enveloping 
the stem. The diameter of such leaf -stalks 
and shoots is increased abnormally and the 
leaves never fully expand and often become 
spotted with purple. Of course such leaves 
are unable to perform their normal functions 
and their duration is brief. One of these 
dwarfed leaves is illustrated in Figure 296. 
Examined under a strong microscope the 
structure of the 
powdery cover- 
ing — the fungus 
— becomes appar- 
ent. We see the 
slender tubes 
which form the 
web-like mass 
and which ex- 
tend in every di- 
rection over the 
surface, and ris- 
ing from these 
tubes are erect 
branches com- 
posed of numer- 
Fl (?. 293. Rose leaf dwarfed ous short cells 
and distorted by the Powdery , . , ,, 
Mildew. which swell out 
and become more rounded as we ap- 
proach the extremity of the branch. These 
cells form the spores or reproductive bodies 
of the fungus, the topmost one falls off and 
then the one immediately below separates 
from the others and so on. 
In Figure 293 some of the horizontal 
threads with three of the upright spore- 
bearing stalks are shown, very much en- 
larged. To the right are three detached 
spores. 
As the fungus grows wholly upon the sur- 
face, how does it obtain 
its needed nourishment? 
Referring to the figure 
j ust cited , we see two very 
fine branches extending 
downwards from one of 
the horizontal threads 
through the cuticle of 
the supporting leaf into 
the epidermal cells be- 
neath. Within these the 
1 tranches swell out into 
bladder-like expansions. ^oorSnr-nocf 
It is through these pecu- Fig. 293. Spore-bear- 
liar branches, winch are Meldew. 
called suckers or haustoria, that the fungus 
draws its food from the host-plant. It is 
no wonder that our roses suffer serious 
injury from this parasite, when we consider 
that many thousands of these little suckers 
which have bored their way into the epi- 
dermal cells, are all pumping at the same 
time the vital juices of the rose from the 
leaves and other affected parts. 
The spores mentioned above are produced 
throughout the season in the greatest abun- 
dance, and as they are ready to germinate 
as soon as ripe, the propagation of the fungus 
is, when the weather or other conditions 
are favorable, most rapid. 
Another kind of spore formation takes 
place towards the close of the season. At 
that time there are developed on the hori- 
zontal threads minute, black, round bodies, 
which are hollow spheres with a compara- 
tively hard covering, and it is within these 
that the second kind of spores are devel- 
oped. These spores are evidently designed 
to preserve the fungus through the winter 
season or protect it from accidental injury. 
It is upon roses out of doors that we have 
most frequently seen this Powdery Mildew, 
but it is even more troublesome in the green- 
house and all should know how to combat 
it. As to the conditions which favor this 
mildew, the observations of Prof. S. T. 
Maynard have led him to the following con- 
clusions: (1) That this disease may be 
brought on by the exposure of the plants to 
draughts of extremely cold air when they 
are growing rapidly; (2) by high tempera- 
ture, running the same both night and day; 
(3) by watering or syringing just before 
night; (4) by too little water ;(5) by extreme 
dryness; (6) by poor drainage; and (7) by a 
deficiency in plant food. 
These conditions do not cause the mildew, 
but only favor the development of the 
fungus, which is the mildew, and it is this 
fungus which causes the disease. If we can 
keep off the fungus or prevent its develop- 
ment by the use of remedies the mildew 
will not appear, no matter how favoring 
the conditions may be. 
Treatment: The Rose Powdery Mildew 
and the Powdery Mildew of the Vine belong 
to the same natural group of fungi — the 
Erysiphe ce — and their treatment is similar. 
They are outside growers, penetrating the 
host only by the little suckers we have de- 
scribed, so that they are exposed to the 
direct application of any remedial or de- 
structive agent. For many years the flowers 
of sulphur has been used to combat the 
Powdery Mildew and, if properly applied, 
is a successful remedy. At low tempera- 
tures the sulphur is inert, hut when the 
temperature is somewhat elevated (70“-90 w ) 
it gives off fumes which are destructive 
to vegetable life, and consequently in its 
use we must guard against injuring the 
plants we seek to protect. By a too liberal 
use of sulphur during the hot days of sum- 
mer the bushes may be defoliated or even 
killed. 
In greenhouses or other inclosed spaces, 
the fumes of sulphur may be forced off by 
heating brimstone in any convenient recep- 
tacle, allowing the vapor to fill the room 
until there is a preceptible odor of sulphur 
throughout. Due care must be taken that 
the brimstone does not take afire or the 
fumes become too dense. 
The liver of sulphur (sulphuret of potas- 
sium) in solution, % to % ounce to the 
gallon of water, is an excellent remedy for 
this rose mildew and one easy of application 
being readily applied with any ordinary 
sprayer. 
Floral Notes for August. 
Now approaches the time when we should 
consider how and with what we shall adorn 
our rooms the coming winter and so make 
preparation for the window gardens that 
shall console us for the loss of our out-of- 
door flower beds when that time arrives. It 
is none too early to begin for it is desirable 
that plants should go into winter quarters 
in the best possible condition if they are to 
give us a satisfactory amount of bloom from 
the start. Some plants such as Zonal Gera- 
niums need cutting back to induce a break 
or start of new growth; take off one-third 
to one-half of the green wood aud aim to 
preserve a shapely appearance to the plant. 
If they are bedded out in the open, take 
them up and put in rich soil, using pots no 
larger than will just accommodate the roots; 
after a while they will need repotting into 
pots from one to two im-hes larger in diam- 
eter. If the plants have been growing all 
summer in large pots, they should be turned 
out, the soil pared off or broken away, and 
the plant returned to the same pot with 
