Scilla. Bulb-Rot (Sclerotinia Bulborum)

Yellow stripes and blotches on leaves in early summer, with olive-brown mold on them. Rots the bulb later. .


-Destroy affected plants. Spray with potassium sulfid. Use new soil thereafter.

Sedum. Leaf-Spot (Septoria Sedi)

Dark circular blotches appear on the leaves and defoliation occurs.


Destroy affected parts by burning.

Sempervivum. Rust (Endophyllum Sempervivi)

Brown rust pustules rupturing epidermis of leaf.


Destroy affected plants as the fungus lives over from year to year in the same plant.

Senecio. Rust (Coleosporium Senecionis)

Orange patches on under surface of leaf.


Keep at a distance from species of Pinus. Burn affected plants to protect neighboring pines.

Sequoia. Blight

See under Pseudotsuga.

Silene. Smut

See under Lychnis.


See under Potato, Eggplant, etc.

Sorbus. Blight

See under Pear.

Spinach. Anthracnose (Colletotrichum Spinaceae)

Spots on leaves, at first minute and watery, gradually increasing in size and becoming gray and dry.


Gather and destroy all diseased leaves.

Mildew (Peronospora Effusa)

Gray, slightly violet, patches of a velvety texture on under side of leaves.


As for Anthracnose, which see.

Spiraea. Rust (Triphragmium Ulmariae)

Reddish yellow and dark brown rust pustules on leaves.


Burn affected parts.

Squash. Wilt

See under Cucurbita.

Strawberry. Leaf-Spot, Or Leaf-Blight (Mycosphaerella Fragariae)

Small purple or red spots appearing on leaves. Leaf appears blotched.


Spray with bordeaux mixture, 4-4-50, soon after growth begins and make three or four additional sprayings during season.

Sweet Pea. Mildew

See under Pea.

Sweet Potato. Black-Rot (Ceratocystis Fimbriata)

Black shank and a black rot of tuber.


Never use sprouts from affected potatoes. Steam sterilize hotbeds.


The sweet potato is susceptible to a large number of rots, soft, dry, hard, white, etc.


Use soil which has not grown diseased sweet potatoes heretofore.

Syringa. Mildew (Microsphaera Alni)

White powdery mildew on upper surface of leaves.


Dust with sulfur.

Twig And Bud Disease (Phytophthora Syringae)

Tips of twigs killed.


Prune off twigs.

Thalictrum. Red-Spot (Synchytrium Anemones)

Red eruptions on stem, leaf and flower. Causing at times swelling and crumpling of the organ.


Burn affected parts.

Thuja. Root-Rot (Polyporus Schweinitzii)

Diseased wood yellowish, cheesy, brittle when dry.

Heart-Rot (Fomes Carneus)

Causes pockets in the affected wood.


Remove all affected wood, using surgery methods.

Tilia. Leaf-Spot (Cercospora Microsora)

Causes spotting and defoliation.


Two sprayings in Massachusetts resulted in longer retention of the leaves.

Tomato. Leaf-Spot (Septoria Lycopersica)

At first small spots appear, which spread until the whole leaf is consumed. Fruit may be attacked.


Spray with bordeaux mixture, 4-4-50, making the first application two weeks after the plants are set out and repeating every two weeks throughout the season.

Downy Mildew

See under Potato.

Late Blight. End-Rot

Due to lack of sufficient soil moisture.


Water soil in dry periods.

Toxylon (Maclura). Rust (Physopella Fici)

Pale cinnamon-brown rust pustules on under side of leaf.


Destroy by burning the affected leaves.

Catalogue of Diseases, continued.


See under Horse-Radish.

Tsuga. Heart-Rot (Trametes Pini)

Light brown decay pitted with small oblong cavities, which are white-lined.

Sap-Rot (Fomes Pinicola)

Soft decay of sap-wood.


Surgery methods.

Tulipa. Mold (Sclerotinia Parasitica)

Olive-brown, velvety patches formed on leaves, stem, and flowers; also, later, small black lumps at base of stems.


Burn affected plants.

Turnip. Club-Root

See under Cabbage. Same disease.


See under Carrot. Same disease.

Ulmus. Tar-Spot (Gnomonia Ulmea)

Black spots on upper surface of leaves.


Burn old leaves in fall or winter.

Heart-Rot (Pleurotus Ulmarius)

Soft rotting of wood.


Surgery methods.

Vaccinium. Leaf-Blister (Exobasidium Vaccinii)

Large blisters on leaves, petioles and stems, of a red or purple color. White bloom beneath.


Remove and burn diseased parts.

Verbena. Mildew. (Erysiphe Cichoracearum And Others)

Powdery mildew growths on leaves.


Spray with any good fungicide or dust with powdered sulfur.

Veronica. Leaf-Spot (Septoria Veronicae)

Well-defined spots on leaves.


Pick off and burn affected leaves.

Vinca. Leaf-Spot (Sphaeropsis Vincae)

Leaves disfigured by spots which occur on the stem at times as well.


Destroy diseased parts of plants.

Violet. Root-Rot (Thielavia Basicola)

Plants make poor growth; roots rotted off.


Start in steam-sterilized soil, and transfer to sterilized beds.


See under Grape.

Walnut. Blight (Pseudomonas Juglandis)

Black spotting of fruit and black cankers on the stems. Twigs and fruit-spurs killed.


None known except such as mentioned under Pear Blight. Grow immune varieties.

Anthracnose, Or Leaf-Blight (Marsonia Juglandis)

See under Hickory-Nut. Same disease.

Watermelon. Mildew

See under Cucumber.

Wilt (Fusarium Vasinfecta)

Wilting of leaves and plant dries up.


None recommended. Resistant varieties should be grown.

Yucca. Leaf-Blotch

See under Agave.


Sec under Corn.

Zinnia. Wilt

See under Dahlia.

Donald Reddick.