Plant Diseases And Insects. Part 13
Description
This section is from the book "The Standard Cyclopedia Of Horticulture Vol2", by L. H. Bailey. See also: Western Garden Book: More than 8,000 Plants - The Right Plants for Your Climate - Tips from Western Garden Experts.
Plant Diseases And Insects. Part 13
Ficus. Leaf-Spot (Leptostromella Elasticw)
Causes spots on leaves. See also under Fig.
Fig. Leaf-Spot (Cercospora bolleana) - Brown spots on leaves. Leaves turn yellow and drop off.
Control
Spray with bordeaux mixture while leaves are young.
Filbert. Black-Knot (Cryptosporella Anomala)
Serious stem disease, canker girdles the stems and kills parts above.
Control
Prune off affected parts and burn.
Forsythia. Leaf-Spot (Alternaria Forsythiae)
Forms sub-circular spots.
Control
Spray with bordeaux mixture. Fraxinus.
Rust (Puccinia Fraxinata)
Swellings of midribs of leaves and petioles with orange rust spots on them.
Control
Keep the common grass Spartina cynosuroides away from the trees.
Freesia. Leaf-Spot And Wilt (Heterosporium Gracile)
Large brown spots with darker margin, numerous; soon the leaves wilt and die.
Control
Spray with ammoniacal copper sulfate. Galanthus.
Decay (Sclerotinia Galanthi)
In place of the flower a shapeless mass is produced covered with brown mildew. Tubers decay also.
Control
Remove all affected parts and burn. Use new soil thereafter.
Gardenia. Rust
See under Coffea. Same disease.
Genista. Root-Tubercles
Beneficial.
Gentiana.
Rust (Puccinia Gentianae)
Lower leaves first attacked, become yellow and die. Disease gradually works upward.
Control
Destroy affected plants.
Geranium. Mildew (Plasmopara Geranii)
Downy mildew of leaves.
Control
Spray with bordeaux mixture.
Gladiolus. Smut ( Urocystis Gladioli)
Black smut pustules on corms.
Control
Destroy affected corms. Use new soil.
Gleditsia. Leaf-Spot (Leptostroma Hypophylla)
Leaflets become covered with small black specks, causing some of them to turn yellow and fall.
Gooseberry. Mildew (Sphaerotheca Mors-Uvae)
A powdery mildew of the fruit and young growth of English varieties.
Control
Spray with potassium sulfid, one ounce to two gallons of water, at intervals after leaves begin to unfold.
Grape. Black-Rot (Guignardia Bidwellii)
Brown circular spots on leaves, black, elongated, sunken pits on petioles, canes, etc., and on the berry a brown rot with shriveling and wrinkling.
Control
Spray with bordeaux mixture, 4-4-50, before rains. Spray (1) when the third or fourth leaf unfolds; (2) as soon as the blossoms have fallen; (3) when berries are size of a pea; (4) about two weeks later. Two more applications if wet season.
Downy Mildew, Or Leaf-Blight (Plasmopara Viticola)
White frost-like patches on under side of the leaf.
Control
Same as Black-Rot. Grapefruit.
Leaf-Spot (Pestalozzia Guepini)
Large spots with dark margins. Leaves fall prematurely. On other species of Citrus also.
Control
Destroy affected leaves. Guava.
Anthracnose (Glomerella Psidii)
Circular brown, decayed areas on fruit. Like apple bitter-rot.
Control
None given. Hedera.
Leaf-Spot And Leaf Blight ( Vermicularia Trichella)
Rapid blackening of the etiolated portion of the leaf.
Control
Remove and burn affected leaves and spray with bordeaux mixture. Helianthus.
Rust (Puccinia Helianthi)
Red rust pustules on leaves of most species of Helianthus.
Control
No specific control measures worked out.
Helleborus.
Leaf-Blotch (Coniothyrium Hellebori)
Large circular brownish blotches of scorched appearance, covered with minute black dots.
Control
Cut off and burn affected leaves.
Hemerocallis.
Leaf-Spot
See under Freesia.
Hibiscus.
Leaf-Spot (Phyllosticta Idsecola)
Indistinct brown spots with whitish centers.
Control
Burn affected leaves.
Mildew (Microsphaera Euphorbiae)
Powdery mildew of leaves.
Control
Dust with sulfur.
Hickory-nut.
Leaf-Spot (Marsonia Juglandis)
Large leaf-spot, causing premature dying of leaves.
Control
Spraying with bordeaux mixture may be of value.
Catalogue of Diseases, continued.
Hollyhock.
Rust (Puccinia Malvacearum)
All parts of plant show reddish brown pustules.
Control
Eradicate mallow. Pick off diseased leaves and burn. Spray every week with bordeaux mixture, 4-3-50.
Horse-Radish.
White Mold (Cystopue Candidus)
Deforming and swelling of leaves and stems, with white powdery surface growth.
Control
Hardly important enough on the radish to necessitate control. Hyacinthus.
Blight (Pseudomonas Hyacinthi)
Serious pest in the Netherlands. Sap-tubes filled with yellow slime.
Control
Destroy all affected plants.
Hydrangea. Leaf-Blight (Phyllosticta Hydrangeae)
Leaf-spot disease which become? serious at times.
Control
Destroy diseased leaves as soon as noticed.
Iberis. Club-Root
See under Cabbage.
Impatiens. Mildew (Plasmopara Obducens)
Downy mildew of the leaves.
Control
Remove affected leaves and spray with bordeauǽ mixture. Ipomoea.
Rust (Coleosporium Ipomceae)
Common rust spotting of leaves.
Control
Destroy affected leaves.
Mildew
See under Convolvulus.
Iris. Leap-Blight (Botrytis Galanthina)
First the leaves and flowers are much distorted and covered with black mold growth; later the bulb may be destroyed.
Control
Eradicate diseased plants and grow in new soiL Juglans.
Leaf-Spot (Gnomonia Leptostyla)
Brown leaf-spot, causing defoliation.
Control
Collect and burn fallen leaves. Spray with bordeaux mixture while leaves are young.
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