Cordyline. Blight

See under Orchids.

Coreopsis. Mildew

(Sphaerotheca humuli variety fuliginea) - Powdery mildew of the leaves.


Dust with sulfur.

Corn. Smut (Ustilago Zeae)

Boils on stalks, ears or tassels, at first white, then black, and, when burst open, containing black powder, the spores.


Cut out developing smut-boils and burn.

Wilt (Pseudomonas Stewartii)

Sap-tubes turn yellow and plant wilts and drys up.


Burn affected plants. Grow varieties not affected.

Catalogue Of Diseases, Continued. Cornus. Twig-Blight (Diaporthe Albocarnis)

Twigs die, bark turns yellow and is covered with numerous small pimples.


Prune off and destroy affected parts.


See under Filbert.

Cosmos. Stem-Blight (Phomopsis Stewartii)

Brown spots rapidly enlarging on stems of mature plants. Parts above wilt and die.


Difficult and no certain methods known. Remove diseased stems and burn. Cotoneaster.

Rhus (Gymnosporangium Clavariseforme)

Orange rust pustules on leaves.


Keep at a distance from junipers.

Cranberry. Blast, Or Scald (Guignardia Vaccinii)

Young flower and fruits blasted, older fruits appear scalded or watery.


Spray five or six times with bordeaux mixture, 5-5-50, to which has been added four pounds of soap. Begin just before the blossoms open. Crataegus.

Rust (Gymnosporangium Sp.)

Orange rust pustules on leaves and petioles.


Keep at a distance from junipers. Cress.

White Mold

See under Horse-Radish.

Crocus. Root-Rot (Rhizoctonia Sp.)

Important in France and likely occurring here.


Sanitation, new soil frequently or soil sterilization.

Cucumber. Blight, Or Mildew (Pseudoperonospora Cubensis)

A blighting and premature yellowing of the leaves.


Spray with bordeaux mixture, 5-5-50, every ten to fourteen days after plants begin to run.


See under Cucurbita.

Cucurbita. Wilt (Bacillus Tracheiphilus)

Sap-tubes are clogged and destroyed, causing the plant to wilt.


Eradicate the striped beetle. Gather and destroy all wilted leaves and plants.

Cupressus. Root-Rot

See under Pine. Same disease.

Twig Disease

See under Chamaecyparis.

Witches' Broom (Gymnosporangium Ellisii)

Fasciation of branches.


Prune off affected parts.

Currant. Wilt, Or Cane-Blight (Botryosphaeriaribis)

Canes die suddenly, the leaves wilting.


No satisfactory method known. Cut out and burn affected plants.

Rust (Cronartium Ribicola)

Brown rust pustules and brown felt-like growth on under side of leaf. Black currants especially susceptible.


Grow at least 500 feet from white pine trees.

Cycas Leaf-Spot (M Ycosphaerella Lulasnei Cladosporium Her-Barum)

Gray spots and final death of leaves.


Remove and burn affected parts.

Cyclamen. Leaf-Spot (Glomerella Rufomaculans variety Cyclaminis)

Spots circular, slightly water-logged, with sharply defined outlines.


Destroy affected leaves by burning.


Similar to Lilium Leaf-Spot, which see.

Dahlia. Wilt (Sclerotinia Sclerotiorum)

White mold on stem, later yellowing and wilting of plant, and finally stem collapses.


Remove and burn affected plants. Green stable manure favors the disease. Daphne.

Leaf-Spot (Mycosphaerella Laureolae)

Similar to Strawberry Leaf-Spot, which see. Date. See under Palms.

Delphinium. Black-Spot (Bacillus Delphini)

Sunken black spots on stem and leaves.


Remove and burn diseased parts.

Dewberry. Leaf-Spot (Septoria Rubi)

Small pale spots of dead leaf-tissue finally becoming dotted with black specks.


No successful method of treatment is known.


See under Carnation.

Digitalis. Mildew (Peronospora Sordida)

Broadly effused, clingy lilac patches of mildew on under surface of leaves.


Spray with bordeaux mixture.

Diospyros. Mildew (Podosphaera Oxyacanthae)

Powdery mildew of the leaves.


Dust with sulfur.

Dracaena. Blight

See under Orchids.

Eggplant. Anthracnose (Gloeosporium Melongenae)

Spots on fruit. Same as on Piper, which see.

Stem Rot (Nectria Ipomaeae)

Spreading spots on the stem.


Spray mixtures may be of avail.

Elaeagnus. Root-Tubercles

See under Alnus. Not destructive

Endive. Rust (Puccinia Endiviae)

Rust spots on leaves.


See under Chicory.

Eucalyptus. Tumor ( Ustilago Vriesiana)

Woody tumors at collar of tree. Production of black soot-like mass of spores between wood and bark.


Surgery methods.

Euphorbia. Blight (Gleosporium Euphorbiae)

Causes death of floral portion just before flowering time and the parts below are soon blighted.


Burn affected plants. Spray with bordeaux mixture.

Catalogue of Diseases, continued.

Fagus. Heart-Rot (Fomes Igniarius)

White, dry, and somewhat solid decay of heart-wood bordered by fine black lines.


See under Arboriculture, Diseases of Trees.

Ferns. Tip Blight (Phyllosticta Pteridis)

Brown spots at or near tips of the fronds covered with minute black dots.


Remove and burn the blighted leaves and then spray with bordeaux mixture.