December, 1918 



THE GARDEN MAGAZINE 



145 



DESCRIPTION OF TROUBLE 



CLEMATIS {Disease) 



Stem rotting at or near the ground level, top blighted 



{Insects) (Also scale insects and two-spotted mite of citrus fruits;) 



COLUMBINE {Diseases) 



Large purplish blotches on the leaves 



Whitish coating on leaves, later with numerous black spore-fruits 



COSMOS {Diseases) 



Large purplish blotches at the lower nodes of stem 

 White powdery coating on leaves 



CYCLAMEN {Diseases) 



Leaf spots irregular, dark at first but turning light and showing con- 

 centric markings 

 Leaf spots circular, watery 



CYCLAMEN {Insects) (See greenhouse insects) 



DAHLIA {Diseases) 



White powdeiy coating on leaves 



Flowers small, often drooping before opening, due to browning and 

 wilting of flower stem 



{Insects) 

 (Also apple leaf-hopper; thrips, red spider, and iris white fly) 

 Buds blasted by punctures of bugs (one-fifth inch) dull yellowish 



or greenish, mottled with reddish brown 

 Larva tunneling up and down inside the main stem 



GERANIUM {Diseases) 



Leaves showing triangular blighted areas extending from the mar- 

 gin inward; also internal brown spots 



{Insects) (Mealy bugs, red spiders, aphids, and white flies, 

 under greenhouse insects) 



GLADIOLUS {Diseases) 



Corms with black sunken rotted spots; leaf spots also produced — 

 reddish-brown color the most common 



GOLDEN GLOW {Disease) 



White granular coating on the leaves 



HOLLYHOCK {Diseases) 



Leaves show yellow to brown, much raised spore-dots 



Leaf spots angular, dark-bordered, centre ashen gray 

 Leaf spots circular, frequently breaking in the centre 

 Brown spots on leaf blades, leaf stalks and stems; on older parts, 

 sunken and light yellow to black 

 {Insects) (See also garden insects) 

 Yellow, sickly looking foliage due to work of dark-green to deep- 

 bluish-green insect (one-quarter inch) with bright blue markings 

 on the head 



HYDRANGEA {Diseases) 



Leaf spots large, rusty brown, sometimes blighting entire top 

 Leaf spots small, white, with red or purple border 

 Orange-colored, powdery spore-dots on lower surface of leaves; 



later angular, reddish brown spore-dots on upper surface, but 



not powdery 



IRIS {Diseases) 



Elliptical, brown, yellow-bordered spots on the leaves 



Dusty or powdery, reddish spore-dots on the leaves 

 Rhizomes or roots self-rotted 



{Insects) ' 



Small, white-winged active insects cause yellowing of leaves or 

 smutting (black mold in honey dew) 

 IVY, BOSTON (Leaf spot of Grape creeper and white fly) 

 IVY, ENGLISH {Diseases) 



Leaves with large, irregular spots, grayish-brown above, brown be- 

 low 



Leaves showing dark brown, extended, dead areas, with many black 



spore-fruits, frequently in circular zones 

 Leaves with brown, raised, definitely bordered spots, terminal or 

 central 



{Insects) (Mealy bugs, white fly, and scale under Garden 

 Insects; also bean aphis) 

 MATRIMONY VINE {Disease) 



Dense, white, powdery coating on the leaves 



MIGNONETTE {Disease) 



Pale leaf spots with yellowish or brown borders, but uniform brown 

 when older 



{Insects) (Corn ear-worm; imported cabbage worm; and two- 

 spotted mite or "red spider" in greenhouse) 



NASTURTIUM {Disease) 



Leaves become yellow, wilt and die; stems with dark vascular 

 strands 



{Insects) (See bean aphis and thrips under bean insects;, im- 

 ported cabbage worm under cabbage) 

 Long, winding mines in leaves made by yellowish maggot (one- 

 eighth inch) 

 OLEANDER {Diseases)^ 



Irregular galls or swellings on stem and twigs 



Dead spots on leaves 



{Insects) (See scale insects and mealy bugs under Garden and 

 general greenhouse insects) 

 Plant lice on tender shoots, yellow or yellow with black spots 



Foliage eaten by a metallic blue beetle (three-eighths inch long) 



PALM {Diseases) 



Leaves showing small or large dead brown spots, generally more or 

 less circular: 



Minute fungous fruits or spore-tufts present 

 Fungous fruits absent at first (Some molds may show later) 



Leaves with small circular raised spore,-dots which suggest scale 

 insects 



(Insects) (General greenhouse insects; scales and mealy bugs) 



PANSY {Diseases) 



Dead, black-bordered spots on leaves and petals 

 Plants wilt and die; stem rotted at or near ground level 

 Brown, powdery spore-dots on leaves and other green parts 

 {Insects) {" red spider" especially) 



NAME 



Stem rot 



Leaf spot 

 Powdery mildew 



Stem-rot 

 Powdery mildew 



Leaf spot 

 Anthracnose 



Powdery mildew 

 Phoma disease 



Tarnished plant- 



bug 

 Stalk-borer 



Bacterial blight or 

 spot 



Hard-rot 



Powdery mildew 

 Rust 



Leaf spot 

 Leaf spot 

 Anthracnose 



Blue sharp-shooter 



Leaf spot 

 Leaf spot 

 Rust 



Leaf spot or blight 



Rust 



Root-stock rot 



White fly 



Leaf spot 



Leaf blight 

 Anthracnose 



Powdery mildew 

 Leaf spot 



Wilt 



Serpentine leaf- 

 miner 



Twig-gall or tuber- 

 culosis 

 Leaf spot 



Oleander or milk- 

 weed aphis 



Blue milkweed 

 beetles 



Leaf spots 



Sun scald (In green- 

 house) 



Palm smut or scale 

 spot 



CAUSE OF TROUBLE 



Anthracnose 



Stem-rot 



Rust 



Asochyla clematidinia 



Ascochyta sp. 

 Erysiphe polygon! 



Phylitinla sp. 

 Erysiphe cichoracearum 



Phoma cyclamenae 



Glomerella rufomaculans, var. 

 cyclaminis 



Erysiphe polygoni 

 Phoma dahliae 



Lygus pratensis 

 Pseudomonas erodii 



Septoria gladioli 



Erysiphe cichoracearum 

 Puccinia malvacearum 



Cercospora althaeina 

 Phyllosticta althaeina 

 Colletotrichum malvarum 



Tettigoniella circellata 



Phyllosticta hydrangeae 

 Cercospora sp. 

 Pucciniastrum hydrangeae 



Heterosporium gracile 



Puccinia iridis 

 (Bacterial rot) 



Aleyrodes spiraeiodes 



Ramularia hedericola 



Phyllosticta concentrica 



Colletotrichum gloesporioides, 

 var. hederae 



Sphaerotheca sp. 

 Cercospora resedae 



Bacillus solanacearum 



Agromyza pusilla 



Bacillus savastanoi 

 Macrosporium nerium 



Aphis nerli 

 Chrysochus cobaltinus 



Various fungi 



Sun shining through water 



drops 

 Graphiola phoenicis 



Colletotrichum viola-tricolons 

 Fusarium violae 

 Puccinia violae 



REMEDY 

 REFERENCE 



23, to 26, 

 26 



5 or 7 

 10 



26,24 

 10 or 9 



26 and 5 or 



7 

 26, 5 or 7 



8, 9, 10 

 No treat- 

 m e n t 



perfected 



18, when in 



nymph 

 38 



33; avoid 

 crowding 



24, 42, 30 

 5 



8,10,7 



23 and 24, 



(fall); 5 

 (spring) 



5,7 



5, 7 



5, often 



18, with 

 prsesure 

 o f 150- 

 200 lbs. 



5,7,8 

 5, 5, 8 



Rarely se- 

 vere 



23, 24, ii 



late fall 



5,8 

 Not severe 

 25 



26 (entire 

 tops) 



5, 7, or 8 if 



away from 

 painted 

 structures 



7 or 10 



7 or 10 



28, control 



insects 



18, (91- 

 400) 



26 



Not serious 



18 



11 or 12 



when 

 beetles 



appear 



7 if severe 



7, 5, or 8 f 



or F ir 



5 



30,31 

 25 



5 pounds resin with 1 pint fish oil, cooling slightly and adding I 



pound soda lye while stirring The mixture should be diluted 



with s gallons of water. The "sticker" makes the bordeaux stick 



I ter ? n< * * S neec * eal m s P ra ying plants having a smooth surface. 



7. Ammoniated Copper Carbonate. Copper carbonate, 5 

 ounces; Ammonia (26 degrees Beaume), 3 pints; Water, 50 gallons. 

 Dilute the ammonia with about 12 pints of water and use just 

 enough to dissolve the copper carbonate. The strong solution 

 may then be diluted to the proper volume. It should be used very 

 soon after preparation. Not as good as bordeaux but may be used 

 when the sediment or stains from that are objectionable, as in late 

 sprayings of small fruits. 



8. Lime-Sulphur. _ Home boiled or factory boiled or commer* 

 cial lime-sulphur is an insecticide as well as a fungicide. It is very 

 extensively used in place of bordeaux for fungous diseases since it is 

 less likely to cause burning or russeting. The home boiled article 

 may be made according to the following formula: Sulphur, 1 to i\ 

 pounds; Fresh stone lime, \ pound; Water, § gallon. (1) Slake 

 the lime m the cooker. (2) Add the sulphur and water. (3) Boil 

 briskly till the sulphur is dissolved (about 45 minutes) stirring con- 

 tinuously and keeping the cooker covered; as it boils down keep 

 adding water. (4) When finished let settle. (5) Use only the clear 

 liquid, which may be stored if kept from the air. Prepared in this 

 way lime sulphur should give a hydrometer reading of about 26 

 degrees Beaume, somewhat weaker than the factory made product. 



[The commercial preparations ready made, and merely needing 

 dilution will be found most convenient, especially when only small 

 quantities are needed. — Ed.] 



9- Potassium Sulphide. Potassium sulphide, 3 to 5 ounces; 

 Water, 10 gallons. Quite generally used for gooseberry and other 

 mildews. Not as effective as lime-sulphur, but may be used if 

 that shows any injurious effects. 



10. Sulphur. Flowers of sulphur or any brand of finely sub- 

 limed sulphur may be used as a dust spray. Sulphur dust has been 

 recommended especially for grape powdery mildew, and may be 

 tried for other powdery mildews also. It is effective for asparagus 

 rust, and has recently been used with fair success in treatment of 

 fungous diseases of apples and nursery stock. There are various 

 commercial forms of sulphur such as "atomic sulphur," "sulphur 

 paste," etc., which may be used as liquid sprays at the rate of 2 to 6 

 pounds to 50 gallons of water. These are valuable in mildew control. 



11. Arsenate of Lead. Arsenate of lead paste, 1 to 2 pounds; 

 Water, 40 to 50 gallons. For newly hatched insects, it is not neces- 

 sary to use it stronger than I to 50. For old or large insects, use 



2 pounds to 50 gallons. Some more resistant forms may require 



3 to S pounds to 50 gallons. First mix the paste with a small 

 quantity of water, then dilute to the desired volume. Powdered 

 arsenate of lead is about twice as strong as the paste, so 1 pound to 

 50 gallons is generally sufficient. 



12. Paris Green. The important compound in this insecticide 

 is arsenious oxide and the commercial grades vary in strength. Ac- 

 cording to the Federal Insecticide Law, the standard is not less than 

 50 per cent, of arsenious oxide, and arsenic in water soluble form must 

 not be present to the equivalent of more than 3^ per cent, of arsen- 

 ious oxide. Paris green was for many years the standard arsenical, 

 but on account of its scorching effect on foliage, has been very 

 largely replaced by arsenate of lead. It may be applied either wet 

 or dry. Mixing with bordeaux, lime, or an inert substance lessens 

 the danger of foliage injury, {a) Dry or as dust spray: Paris green, 



1 pound; Air slaked lime, gypsum, or flour, 25 to 50 pounds, {b). 

 Wet or as liquid spray: Paris green, 1 pound; Fresh stone lime, 



2 pounds; Water, 100 to 150 gallons. London purple, an arsenate 

 of lime, was formerly used. Its arsenic content is more variable; 

 it is liable to burn foliage, and consequently it has fallen into disuse. 



13. Kerosene Emulsion. This contact insecticide may be 

 prepared as follows: ^ pound Fish oil soap ( or 1 pound laundry 

 soap); 2 gallons Kerosene; 1 gallon Water. Dissolve the soap in 

 hot water, remove from fire and add the kerosene. Churn or 

 pump mixture until creamy. Dilute as follows: {a) Dormant 

 spray: 1 part to 5 to 7 parts water, {b) Summer spray: 1 part to 

 IO to 15 parts water. Foliage injury is likely in many crops and 

 consequently tobacco preparations have come into more general 

 use for plant lice. Crude oil may be used in the place of kerosene. 



14* Distillate Emulsion. 20 gallons Distillate (28 degrees 

 Beaume); 30 pounds Whale oil soap; 12 gallons Water. Dissolve 

 soap in water and boil. Add distillate and mix thoroughly while 

 hot. For use add 1 gallon of stock to 20 gallons of water. 



15. Carbolic Acid Emulsion. 40 pounds Whale oil soap; 

 5 pounds Crude carbolic acid; 40 gallons Water. Dissolve soap 

 in hot water, add the carbolic acid and boil 20 minutes. For use 

 add 1 gallon of the stock to 20 gallons of water. 



16. Miscible Oils. These are proprietary sprays and are 

 concentrated oil emulsions intended primarily for use against San 

 Jose scale. The dilution is 1 gallon to frdm 15 to 17 gallons of 

 water. 



17. Whale Oil Soap. This is more effective than ordinary- 

 soap. An excellent article may be prepared as follows: 6 pounds 

 Caustic soda; 22 pounds Fish oil; | gallon Water. Dissolve the 

 caustic soda in the water, then add the fish oil very gradually while 

 stirring constantly and vigorously. Boiling is unnecessary, but 

 the mixture should be stirred for about 20 minutes after the oil has 

 been added. 



18. Nicotine. Use of "Black leaf 40" or other 40 per cent, 

 nicotine preparation, 1 gallon; water, 800 to 1,600 gallons. Add 



4 pounds of soap for each 100 gallons of spray. Dissolve the soap 

 in hot water and add to the mixture to make it spread and stick 

 better. When used with lime sulphur, the soap may be omitted. 

 In some cases a stronger mixture is required, as for the Chrysanthe- 

 mum leaf miner 1 part to 200 to 400. 



19. Water Only. Garden slugs may be knocked off by the 

 jet from the hose and red spider is controlled by an adequate supply 

 of moisture in the air. 



20. Dust Repellants. Certain small or soft bodied insects 

 may be controlled by the use of inert dust repellants. Thus flour, 

 air slaked lime, limoid, gypsum, etc., may be sprinkled on the plants. 

 Such treatment is employed with success in early attacks upon seed- 

 lings in the garden. 



Fumigation 



21. Hydrocyanic Acid Gas. This is a deadly poison produced 

 by tne action of sulphuric acid to which water has been added, on 

 either potassium or sodium cyanide. Particulars may be had on 

 application. 



22. Tobacco. Tobacco fumes may be used in the control of 

 plant lice, thrips, mites, etc., on house or greenhouse plants. Foliage 

 injury of tender plants may be avoided by burning the tobacco 

 slowly or by the use of one of the several proprietary, volatile to- 

 bacco products now on the market. 



Sanitary Measures 



These are mainly in the nature of preventive steps, but oftentimes 

 they deal with material already diseased or so weakened that it is easily 

 subject to infection or injury. They are especially important in the 

 control of diseases caused by organisms too small to be easily seen, and 

 which the gardener is likely to overlook as important causes of trouble. 



23. Destruction of Dead Leaves in which the organism 

 winters over. Such measures are never perfectly effective alone but 

 are valuable in supplementing other methods of control, especially 



