Smut ( Urocystis Cepulae)

Black pustules on leaves and bulbs. Seedlings may be killed outright.


Grow seed in new soil. Drill in with the seed one hundred pounds of sulfur and fifty pounds of air-slaked lime to the acre.

Opuntia. Spot (Diplodia Opuntiae)

Sometimes a serious pest of cactus.

Orach. Galls (Urophlyctis Pulposa)

Glassy swellings on leaves, stems and flowers of Chenopodium and A triplex.


Burn affected plants.

Orange. Black-Mold (Capnodium Citri)

Black mold-like growth on leaves and fruit.


Spray with any good fungicide.

Orchids. Leaf-Blight (Glomerella Cincta)

Leaf dies back from the tip, turning brown.


Burn affected leaves. Spray frequently then with bordeaux mixture.

Ornithogalum. Warts (Synchytrium Niesii)

Dirty white warts on leaves, bounded by a dark line.


Burn diseased leaves.

Paeonia. Stem-Rot And Wilt (Sclerotinia Paeoniae)

Gradual wilting and dying of leaves caused by decay of stem at or near surface of soil.


Spray the stems frequently with a strong fungicide. Burn affected plants.

Palms. Leaf-Spot (Gloeosporium Allescheri)

May cause ultimate death of leaves.


Frequent spraying with bordeaux mixture and eradication of diseased leaves may prove beneficial.

Catalogue of Diseases, continued.

Pandanus. Black Canker (Nectria Pandani)

Kills branches and entire plants.

Black pustules on bark oozing black tendrils.


Cut out diseased portions as soon as noticed.

Pansy. Leaf-Spot (Peronospora Violas)

Discolored spots with pale violet growth on them.


Spray with bordeaux mixture.

Papaver. Mildew (Peronospora Arborescens)

Downy mildew of wild and cultivated poppies. Especially injurious to seedlings of garden species.


Spray with bordeaux mixture.

Parsley. Leaf-Scorch (Septoria Petroselini)

Small scattered brown patches, which increase in size until whole leaf is covered.


Spray early with dilute bordeaux. Pick off and burn affected leaves.

Parsnip. Leaf-Blight

See under Celery, Early Leaf-Blight.

Pea. Miidew (Erysiphe Polygoni)

A powdery mildew on pods and leaves.


Dust dry sulfur over the plants.

Peach. Blight (Coryneum Beyerinkii)

A spotting, gumming and death of the buds and twigs, particularly in the lower parts of the tree. The fruit drops.


For California conditions, two applications bordeaux mixture, 5-5-50, or lime-sulfur, 1-10, (1) in November or December, and (2) in February or March.

Leaf-Curl (Exoiscus Deformans)

Leaves curl and wrinkle.


Spray with lime-sulfur, 1-11, before buds swell.

Brown-Rot (Sclerotinia Fructigena)

Rot on fruit and cankers on limbs.


Spray with self-boiled lime-sulfur, 8-8-50, adding two pounds arsenate of lead. Spray (1) about time shucks are shedding from young fruit; (2) two or three weeks later; (3) one month before fruit ripens.

Scab, Or Black-Spot (Cladosporium Carpophilum)

Black scablike spots on fruit.


Self-boiled lime-sulfur applied as under Brown-Rot.


A fatal disease. Red spots in fruit. Tuft-like growth of new shoots and finally yellow foliage.


Burn affected trees.

Pear. Blight (Bacillus Amylovorus)

Flowers, young fruit, twigs, and leaves turn black and die. Limbs die back and sunken cankers form in bark.


Eradicate all wild hawthorns, pears and apples. Inspect and remove all blighted parts of tree. Paint wounds with coal-tar.


Very similar disease to Apple Scab, which see.

Pecan. Leaf-Blotch (Mycosphaerella Convexula)

Dark-colored blotches covered with minute black dots on leaves in midsummer.


None given.

Pelargonium. Dropsy

Translucent spotting of leaf. Spots finally die.


Withhold water until absolutely necessary.

Persimmon. Anthracnose (Glomerella Rufomaculans)

Similar if not identical to Piper Anthracnose, which see.

Petunia. Wilt

See under Dahlia.

Phlox. Stem-Canker (Pyrenochaeta Phlosidiss)

Canker just above the ground on the stem. Plant dies; first turning yellow and then falls over.


Diseased stems should be removed and burned.

Physalis. Wilt (Bacillus Solonacearum)

Pith of stem turns brown, sap-tubes filled with viscid ooze.


Get rid of insects such as potato beetle and burn all affected plants.

Picea. Leaf-Spot And Leaf-Cast (Phoma Sp.)

Causes discoloration and dropping of needles. Black dots on affected needles.


Clean up all fallen needles and burn.

Drought Injury

Drying up of needles. Water in dry weather.

Pine. Root-Rot (Armillaria Mellea)

Tops turn yellow and die, swelling of trunk at surface of ground. Decay of roots with black threads abundantly present. Toadstools around base of tree.


Dig up and burn and destroy all toadstools near the affected trees.

Pineapple. Heart-Rot

Browning of the axis of the fruit, due to excessive moisture at time of ripening.


Keep down humidity in greenhouses.

Piper. Anthracnose (Glaeosporium Piperatum)

Spots on leaves of plants. Also apple bitter-rot fungus (Glomerella rufomaculans) causes similar spots on the fruits.


Frequent spraying with bordeaux mixture.

Platanus. Anthracnose

See under Oak. Same disease.

Plum. Black-Knot (Plowrightia Morbosa)

Black tumorous swellings from 1 to several inches in length, on limbs and twigs.


Burn all affected parts in the fall. Burn whole tree if badly affected.