DISEASES AND INSECTS 



DISEASES AND INSECTS 1031 



CATALOGUE OF DISEASES, continued. 



Cornus. TWIG-BLIGHT (Diaporthe albocarnis). Twigs die, bark 

 turns yellow and is covered with numerous small pimples. 



Control. Prune off and destroy affected parts. 

 Corylus. See under Filbert. 



Cosmos. STEM-BLIGHT (Phomopsis stewartii). Brown spots 

 rapidly enlarging on stems of mature plants. Parts above 

 wilt and die. 



Control. Difficult and no certain methods known. Remove 

 diseased stems and burn. 



Cotoneaster. RHUS (Gymnosporangium clavariae forme). Orange 

 rust pustules on leaves. 



Control. Keep at a distance from junipers. 



Cranberry. BLAST, or SCALD (Guignardia vaccinii). Young flower 

 and fruits blasted, older fruits appear scalded or watery. 



Control. Spray five or six times with bordeaux mixture, 

 5-5-50, to which has been added four pounds of resin. fish-oil 

 soap. Begin just before the blossoms open. 



Cratsegus. RUST (Gymnosporangium sp.). Orange rust pustules 

 on leaves and petioles. 



Control. 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. 



Control. Sanitation, new soil frequently or soil sterik'zation. 

 Cucumber. BLIGHT, or MILDEW (Pseudoperonospora cubensis). 

 A blighting and premature yellowing of the leaves. 



Control. Spray with bordeaux mixture, 5-5-50, every ten 

 to fourteen days after plants begin to run. 

 WILT. See under Cucurbita. 



Cucurbita. WILT (Bacillus tracheiphilus). ^-Sap-tubes are clogged 

 and destroyed, causing the plant to wilt. 



Control. Eradicate the striped beetle. Gather and destroy 

 all wilted leaves and plants. 



Cupressus. ROOT-ROT. See under Pine. Same disease. 

 TWIG DISEASE. See under Chamxcyparis. 



WITCHES' BROOM (Gymnosporangium ettisii). Fasciation of 

 branches. 



Control. Prune off affected parts. 



Currant. WILT, or CANE-BLIGHT (Botryosphseriaribis). Canes die 

 suddenly, the leaves wilting. 



Control. 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. 



Control. Grow at least 500 feet from white pine trees. 

 Cycas. LEAF-SPOT (Mycosphxrella tulasnei=Cladosporium her- 

 barum). Gray spots and final death of leaves. 



Control. Remove and burn affected parts. 



Cyclamen. LEAF-SPOT (Glomerella rufomaculans var. cyclaminis). 

 Spots circular, slightly water-logged, with sharply defined 

 outlines. 



Control. Destroy affected leaves by burning. 

 BLIGHT. 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. 

 Control. Remove and burn affected plants. Green stable 

 manure favors the disease. 



Daphne. LEAF-SPOT (Mycosphxrella laureolse). Similar to Straw- 

 berry Leaf-Spot, which see. 

 Date. See under Palms, 



Delphinium. BLACK-SPOT (Bacillus delphini). Sunken black spots 

 on stem and leaves. 



Control. Remove and burn diseased parts. 



Dewberry. LEAF-SPOT (Septoria rubi). Small pale spots of dead 

 leaf-tissue finally becoming dotted with black specks. 



Control. No successful method of treatment is known. 

 Dianthus. See under Carnation. 



Digitalis. MILDEW (Peronospora sordida). Broadly effused, dingy 

 lilac patches of mildew on under surface of leaves. 



Control. Spray with bordeaux mixture. 



Diospyros. MILDEW (Podosphxra oxyacanthx). Powdery mildew 

 of the leaves. 



Control. Dust with sulfur. 

 Dracaena. BLIGHT. See under Orchids. 

 Eggplant. ANTHRACNOSE (Glceosporium melongeme). Spots on 



fruit. Same as on Piper, which see. 

 STEM ROT (Nectria ipomaex). Spreading spots on the stem. 



Control. Spray mixtures may be of avail. 



Elaeagnus. ROOT-TUBERCLES. See under Alnus. Not destructive 

 Endive. RUST (Puccinia endirise). Rust spots on leaves. 



STEM-ROT. 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. 



Control. Surgery methods. 



Euphorbia. BLIGHT (Glceosporium euphorbise). Causes death of 

 floral portion just before flowering time and the parts below 

 are soon blighted. 



Control. Burn affected plants. Spray with bordeaux 

 mixture. 



CATALOGUE OF DISEASES, continued. 



Fagus. HEART-ROT (Fames igniarius). White, dry, and some- 

 what solid decay of heart-wood bordered by fine black lines. 

 Control. 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. 



Control. Remove and burn the blighted leaves and then 



spray with bordeaux mixture. 

 Ficus. LEAF-SPOT (Leptostromella elasticx}. 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 forsythix). Forms sub- 

 circular spots. 



Control. Spray with bordeaux mixture. 



Fraxinus. RUST (Puccinia frnxinata). 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 gentianse). Lower leaves first at- 

 tacked, 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 hypophytta). Leaflets become 

 covered with small black specks, causing some of them to 

 turn yellow and fall. 



Gooseberry. MILDEW (Sphserotheca mors-uvse). 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 bidweUii). Brown circular spots 

 on leaves, black, elongated, sunken pits on petioles, canes, 

 etc., and on the berry a brown rot with shriveling and wrink- 

 ling. 



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 (Pestalozria 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 tricheUa). 

 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 hettebori). Large cir- 

 cular 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 idaecola). Indistinct brown 

 spots with whitish centers. 



Control. Burn affected leaves. 

 MILDEW (Microsphsera euphorbia). 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. 



