Brown-Rot

See under Peach.

Polygonum. Tar-Spot (Rhytisma Bistortae)

Black tar-like spots on leaves.

Control

Burn affected leaves.

Pomegranate. Internal Rot (Sterigmatocystis Castanea)

Central cavity of fruit occupied by a black sporulating fungus.

Control

None known.

Catalogue of Diseases, continued.

Pomelo. Wither-Tip (Colletotrichum Glaeosporioides)

Anthracnose cankers of stem, spots on leaves and flowers and general wilting of tips of branches.

Control

Prune off affected parts and spray with bordeaux mixture.

Populus. Heart-Rot (Polyporus Sulphureus)

Red rot of the wood, which finally breaks up into cubes.

Control

Surgery methods.

Potato. Early Blight (Alternaria Solani)

Circular spots, usually in July and final blighting of whole leaf.

Control

Spray with bordeaux mixture, every ten days, beginning when plants are 6 to 8 inches high.

Late Blight And Potato-Rot (Phytophthora Infestans)

Quick-spreading watery appearing spots in leaves. Mildew on under side. Plants appear as scalded by hot water. Tubers rot in soil or soon after digging.

Control

Spray with bordeaux mixture, 5-5-50, at least three applications and in wet seasons, six or more may be necessary. Use from forty to one hundred gallons per acre.

Scab (Oospora Scabies)

A scabby and pitted roughness of the tubers.

Control

Keep lime and ashes off the land. Soak uncut seed tubers in a solution of formalin, one pint to thirty gallons of water for two hours. Avoid land that has grown scabby potatoes.

Potentilla. Leaf-Spot

See under Strawberry.

Primula. Rot (Botrytis Sp.)

Similar to rot of Paeonia, which see.

Prune

See under Plum.

Prunus

See under Cherry, Plum and Peach.

Pseudotsuga. Blight (Sclerotinia Fuckeliana)

Gray mold of seedlings and younger shoots of older trees in moist situations.

Control

Spray with bordeaux mixture.

Psidium

See under Guava.

Pyrus

See under Apple and Pear. Quince.

Blight

See under Pear.

Rust (Gymnosporangium Globosum)

Orange rust of fruit.

Control

Destroy red cedars in the neighborhood, also wild apples and hawthorns. Spray as for Apple Scab. Radish. White "Rust" or Mildew (Albugo candidus). - A whitish powdery growth on the leaves and petioles, often causing distortion.

Control

Steam sterilize the soil before planting.

Club-Root

See under Cabbage.

Black-Rot

See under Cabbage.

Ranunculus. Mildew (Plasmopara Pygmaea)

Downy mildew of leaves.

Control

Spray with bordeaux mixture.

Raspberry. Anthracnose (Glaeosporium Venetum)

Circular or elliptical, gray scab-like spots on the canes.

Control

Remove diseased canes as soon as fruit is picked. Avoid taking young plants from diseased plantings.

Crown-Gall

See under Blackberry.

Red, Or Orange Rust (Gymnoconia Interstitialis)

Dense red powdery growth on under side of leaves of black varieties and blackberries.

Control

Dig up and destroy affected plants.

Leaf-Spot

See under Dewberry. Same disease.

Retinospora. Gall (Gymnosporangium Sp.)

Swellings on limbs and twigs with red-brown pustules covering them.

Control

Prune off affected parts and keep at a distance from species of Pomeae.

Rhamnus. Rust (Puccinia Coronata)

Irregular yellow blotches, with yellow pustules on under side of leaf. Also on fruit and flowers.

Control

Keep at a distance from "rusted" cereals and other grasses.

Rheum. Soft-Rot

See under Carrot.

Rhododendron. Galls (Erobasidium Rhododendri)

Galls of the size of a pea or larger, at first pale green, then red and brownish covered with white bloom.

Control

Leaves bearing galls should be removed and burned.

Rhubarb. Soft-Rot

See under Carrot.

Rhus. Canker And Twig Blight (Endothia Parasitica)

See under Chestnut. Causes death of twigs.

Ribes

See under Currant and Gooseberry.

Richardia. Soft-Rot (Bacillus Aroideae)

Soft rotting of conns (bulbs) and leaves.

Control

Change soil every three or four years. Reject corms which show the disease.

Robinia. Heart-Rot (Trametes Robiniophila And Fomes Rimosus)

Heart-wood converted into punk. Shelf-like bodies grow from wounds.

Control

Surgery methods.

Rose. Mildew (Sphaerotheca Pannosa)

A white powdery mildew on new growth.

Control

In greenhouses, keep steam-pipes painted with a paste of equal parts lime and sulfur mixed in water. Out-of-doors roses should be dusted with sulfur flower or sprayed with potassium sulfid, one ounce to three gallons of water.

Stem-Blight

Similar to Raspberry Anthracnose, which see.

Catalogue of Diseases, continued.

Rubus

See under Raspberry.

Salix. Rust

Numerous species of the rust fungi produce red rust spots on the leaves.

Control

Keep at a distance from species of conifers.

Heart-Rot (Trameles Suaveolens)

Enters through wounds.

Control

Surgery methods.

Salsify. Mildew (Albugo Tragopogonis)

Distortion and white blisters on host.

Control

Eradicate affected plants and grow on new soil apart from wild and cultivated species of the Composiatae.

Sambucus. Cankers

See under Lonicera.

Sarracenia. Blight

See under Orchids.

Saxifraga. Rust (Puccinia Pazschkei And P. Saxifrage)

Dark brown concentric circles of rust pustules on upper surface of the leaves.

Control

Burn affected leaves.