DISEASES AND INSECTS 



DISEASES AND INSECTS 1029 



solution may be boiled at home and stored in barrels to be used as 

 needed. For method of preparation see page 1043. 



Test with a Baum<i hydrometer, which has a scale reading from 

 25 to 35. Dilutions are reckoned from a standard solution test- 

 ing 32. If the solution tests only 28, it is not so strong as stand- 

 ard, and cannot be diluted so much as a solution testing 32. The 

 table shows the proper dilution for solutions testing 25 to 35 

 Baum6: 



Decimals are given in all cases, but for practical purposes the 

 nearest even gallon or half gallon can be used, unless appliances 

 for more accurate measurement are at hand. It is understood in 

 making all dilutions that water is added to one gallon of the con- 

 centrate to make the stated amount. Do not measure out the 

 stated amount of water and add the concentrated solution to it. 



(5) Commercial concentrated lime-sulfur. As manufactured 

 and placed on the market is a clear amber liquid, and should test 

 32 to 35 Baum6. It costs about 20 cents a gallon retail, and 

 comes ready to pour into the spray tank. For apple and pear dis- 

 eases. Arsenate of lead can be used with this solution, and increases 

 its fungicidal value. 



(6) Scott's self-boiled lime-sulfur. This is a mechanical mix- 

 ture of the two substances, and is really not boiled, the heat being 

 supplied by the slaking lime. In a small barrel or keg place eight 

 pounds of good quicklime. Add water from time to time in just 

 sufficient amounts to prevent burning. As soon as the lime begins 

 to slake well, add slowly (preferably through a sieve) eight pounds 

 of sulfur flour. Stir constantly, and add water as needed. As soon 

 as all bubbling has ceased, check further action by adding a quan- 

 tity of cold water, or pour into a barrel or tank and make up to 

 fifty gallons. Keep well agitated. Very effective against peach 

 scab and brown rot. Several other formulas have been used: 

 10-10-50 and 5-5-50. Arsenate of lead can be used with this 

 mixture. 



By using boiling water and allowing the hot mixture to stand for 

 half an hour, a stronger spray mixture than the above can be 

 secured. It cannot be used safely on peaches, but has been used 

 successfully on grapes for surface mildew. The addition of sulfate 

 of iron or sulfate of copper, one or two pounds to fifty gallons, has 

 been used for apple rust. 



Potassium sulfid (liver of sulfur). -^-Simple solution, three ounces 

 in ten gallons of water. For mildew in greenhouses, on rose bushes 

 and other ornamentals. 



Resin-sal-soda sticker. Resin, two pounds; sal-soda (crystals), 

 one pound; water, one gallon. Boil until of a clear brown color, 

 i.e. from one to one and a half hours. Cook in an iron kettle in 

 the open. Add this amount to fifty gallons of bordeaux. Useful 

 for onions, cabbage, and other plants to which spray does not 

 adhere well. 



Sulfate of copper (blue vitriol). Dissolve one pound of pure 

 sulfate of copper in twenty-five gallons of water. A specific for 

 peach leaf-curl. Apply once before buds swell in the spring. Cover 

 every bud. For use in preparing bordeaux mixture. Costs from 

 5 to 7 cents a pound, in quantity. 



Sulfate of iron (copperas). A greenish granular crystalline sub- 

 stance. Dissolve one hundred pounds in fifty gallons of water. 

 For mustard in oats, wheat and the like, apply at the rate of fifty 

 gallons an acre. Also for anthracnose of grapes as a dormant spray. 



Sulfur (ground brimstone, sulfur flour, flowers of sulfur). 

 Should be 99 per cent pure. Valuable for surface mildews. Dust 

 on dry or in the greenhouse used in fumes. Evaporate it over a 

 steady heat, as an oil-stove, until the house is filled with vapor. Do 

 not heat to the burning point, as burning sulfur destroys most 

 plants. To prevent burning, place the sulfur and pan in a larger 

 pan of sand and set the whole upon the oil-stove. 



DONALD REDDICK. 

 Catalogue of diseases. 



Abies. WITCHES' BROOM (dEcidium elatinum. Melampsorella ela- 

 tina). On fir causing swellings, cankers, and witches' brooms. 

 Control. Prune off all affected parts. 



Abutilon. RUST. See under Hollyhock. 



CONTAGIOUS CHLOROSIS. Variegated leaves. 



Control. Remove variegated leaves and their shoots, keep 

 in dark and remove any further variegated leaves; then the 

 plant should remain green. 



Acacia. RUSTS (Mcidium sp.). Distorts branches and twigs. 

 Control. Prune off diseased parts. 



CATALOGUE OF DISEASES, continued. 



Acer. TAR-SPOT (Rhytisma acerinum). Black tar-like spots on 

 upper side of the leaves. 



Control. Burn all old leaves in fall or winter. 

 SUN SCALD or SCORCH. Maples suffer commonly from a drying 

 up of the foliage, due to over-transpiration of water at times 

 when hot winds occur. 



Actinidia. MILDEW (Uncinula necator). See under Ampelopsis. 

 ^Esculus. LEAF-SPOT (Phyllosticta paviae). Irregular spots develop 

 rapidly, the larger part of the leaf being involved. Leaves 

 fall prematurely. 



Control. Spray with bordeaux mixture, beginning when the 

 leaves are about half -grown and repeating the process every 

 three weeks. 



Agave. LEAF-BLOTCH (Coniothyrium concentricum). Grayish, 

 more or less circular dead patches, ranging from J to 1 inch 

 in diameter. 



Control. Remove and burn diseased leaves. 

 Allium. See under Onion. 



Almond. BLIGHT. (Coryneum beyerinkii). See Peach Blight. 

 YELLOWS. See under Peach. 



Alnus. ROOT-TUBERCLES. Clumps of small tubercles on the roots. 



Not important. 



WITCHES' BROOMS and BLADDERY DEFORMATIONS OF FLOWERS 

 (Exoascus sp.). Broom-like tufts of branches and irregular 

 deforming and contortion of fruits. 



Control. See under Peach Leaf-Curl. 

 Alyssum. MILDEW (Erysiphe polygoni). See under Verbena. 



Disease very similar. 

 Amarantus. WHITE "RUST" or MILDEW (Albugo bliti). See 



similar disease under Radish. 



Amelanchier. RUST (Gymnosporangium sp.). Orange rust spots 

 on leaves. 



Control. Keep junipers at a considerable distance. 

 WITCHES' BROOM (Dimerosporium collinsii). Thick twisted 

 broom-like growth of branches. 



Control. Cut out the brooms. 

 Ampelopsis. BLACK-ROT. See under Grape. 



MILDEW (Uncinula necator). Powdery mildew growths on 

 upper side of leaf. 



Control. Dust with sulfur. 



Anemone. ROOT-DECAY (Sclerotinia tuberosa). Rhizomes decayed 

 and large lumps form on the outside. 



Control. Eradicate affected rhizomes and the cup-like 

 fungous bodies near such plants. 

 RUST. Several rusts attack species of Anemone. 

 Anthurium. BLIGHT (Glomerella cincta). See under Orchids. 

 Apple. BLIGHT. The same disease as Pear Blight, which see. 

 CANKER. Smooth cankers in bark of trunk or limbs usually 

 indicate blight (Bacillus amylivorus); rough ones, New York 

 apple-tree canker (Sphceropsis malorum), or the nail-head 

 canker ( Numularia discreta). 



Control. As soon as noticed, cut away dead bark and wood 

 to the living tissue and paint over with lead paint or coal-tar. 

 SCAB (Venluria insequalis). Olive^green, brownish or blackish 

 scab-like spots on leaves and fruit. 



Control. Rake and burn or plow under old leaves very 

 early in spring. Spray with lime-sulfur 32 Baum, 1-40, 

 or bordeaux, 3-3-50: (1) when blossom buds show pink; 

 (2) when majority of petals have fallen: (3) three weeks 

 after 2, depending upon the weather; (4) if a late attack is 

 feared, spray before fall rains begin. 

 Apricot. YELLOWS. See under Peach. 



BLACK-SPOT or SCAB. See under Peach. 

 Aquilegia. MILDEW (Erysiphe polygoni). See under Verbena. 



Disease very similar. 



BLACK-SPOT (Bacillus delphini). Sunken black spots on leaves 

 and stems. 



Control. Remove and burn diseased parts. 

 Artemisia. RUST (Puccinia asteris). Same rust as on Asters, 



which see. 



Artichoke. SOFT-ROT. See under Carrot. 



Arum. LEAF-SPOT (Protomyces art). Irregular bleached patches 

 on leaves and leaf-stalks of A. maculatum. 



Control. Burn diseased plants. 



Asparagus. RUST (Puccinia asparagi). A rust of the tops which 

 is often so severe as to kill them, thus interfering with root- 

 development. 



Control. Dust with flowers of sulfur about every three 

 weeks while dew is still on in the morning. Use dusting- 

 machines. 



Aspidistra. LEAF-BLOTCH (Ascochyta aspidistrse). Large, irregular, 

 bleached spots with black streaks running across. 



Control. Remove diseased leaves. 

 Aster. RUST (Puccinia asteris). Brown rust of leaves. 



Control. Eradicate the affected leaves. 



Aucuba. FREEZING. Young leaves suffer from spring frosts. 

 Auricula. LEAF-BLOTCH (Heterosporium auriculi). Three or 

 four olive-green spots on each leaf. Spots become brown and 

 fall out. 



Control. Do not have excessive moisture. Spray with 

 potassium sulfid and ventilate well. 



Avocado, or Persea. ANTHRACNOSE (Colletotrichum glceosporioidet). 

 See under Pomelo. 



