122 PICTORIAL PRACTICAL CARNATION GROWING. 
Chapter X.—Diseases and Enemic¢s, 
[By “ PATHOLOGIST.” ] 
I.—Mildew. 
CARNATIONS, both under glass and in the open ground, are liable 
to attack by a white mould commonly called mildew (Erysiphe 
communis), which produces patches of a white or grey meal-like 
coating here and there on the leaves. The attack cripples, stunts, 
and disfigures the growths. The young growth of plants raised late 
from layers is often affected, possibly from tenderness of the growths 
encouraged by the rooting so late in the season. The dews of late 
summer, and the moisture on the leaves for long periods, render the 
plant more susceptible. 
It is towards autumn that mildew makes its appearance on the 
young plants, commonly after a period of dry weather, especially on 
light soils outdoors, and on plants that after being potted up are kept 
close and moist in frames or houses. If allowed to spread the 
mildew soon renders the plants weak, and they give indifferent 
results as compared with others kept clear of the pest. The closer 
and moister the conditions, the more rapidly the mildew develops. 
Mildew is best avoided out of doors by choosing an open and 
airy situation, and under glass by giving plenty of air, with a position 
in full light. Great care is necessary in watering. Spraying with a 
solution of sulphide of potassium (4 oz. to 1 gallon of water) about 
twice a week, prevents and represses attacks in the conidial stage 
(Oidium erysiphoides), which is the proper one at which to combat 
it. The fungicide has no effect on the epiphytal parasite in its 
perithecial form or resting stage. The grower should pick off and 
burn any leaves with minute black bodies on them. 
As a dry preparation for dusting on the plants, flowers of sulphur 
mixed with one-third of slaked lime answers well, if the dusting is 
FUNGOID ENEMIES. FIG. 59 (NEXT PAGE).—MILDEW. 
A, a young plant in a 43-inch pot badly affected with mildew: a, stumps of 
shortened leaves at layering; +, young grass crippled and stunted ; ¢, 
patches of mildew on the leaves; d, the central growth deprived of 
nourishment and distorted. 
B, a young plant outdoors infested: e, patches of mildew on the leaves; /f, 
stunted crown. 
C, mildew, or conidial condition of the fungus named Oidium erysiphoides : 
g, mycelium efiused, arachnoid, on both surfaces of the leaf; Ah, 
conidiophore ; i, conidium or spore, magnified. 
D, the final or resting stage of the fungus, Erysiphe communis: /, peri- 
thecium, superficial, spherical, minute (just visible to the naked eye as 
black points), scattered or gregarious ; /, appendages short, asci (contained 
in perithecium) sub-globose, four to eight spored, four to eight in a 
perithecium ; spores elliptical, magnified. 
