DISEASES OF PLANTS. 53 



Disease susceptibility of apple varieties in Ohio, A. D. Selby (Ohio State 

 Eort. 8oc. Ann. Rpt., ^6 (1913), pp. 73-78). — A tabular list is given of disease 

 susceptibility in Ohio of 38 varieties of apples to crown gall, collar rot, blister 

 canker, twig blight, scab, bitter rot, blotch, black rot of fruit and canker, fruit 

 spot or Baldwin spot, and fungus fruit spot due to Cylindrosporium pomi. 



Black spot canker or apple tree anthracnose, W. H. Lawrence (Bien. Rpt. 

 Bd. Hort. Oregon, 12 (1911-12), pp. 93-97).— The author gives a description of 

 the black spot canker due to Glomsporium malioorticis, the perfect form of 

 which is Ncofahrca malicorticis. A previous account of his investigations on 

 this subject has been noted (E. S. R., 16, p. 790). Among the more important 

 facts recently observed regarding it, is the occurrence of the disease on stored 

 fruit from orchards in which anthracnose canker was not known to occur. 



The author advises thorough, repeated spi*aying for the control of this fungus, 

 autumn spraying following the maturing of the fruit being considered of de- 

 cided advantage over later applications. The use of a Bordeaux petroleum 

 emulsion was briefly tested and seems to be of considerable promise. 



The control of apple blotch, D. E. Lewis (Kansas Sta. Bui. 196 (1913), pp. 

 517-57 It, figs. 21). — ^An account is given of experiments for the control of the 

 apple blotch due to PhyUosticta solitaria. This disease is of rather common 

 occurrence in the orchards of Kansas, frequently causing over 90 per cent of 

 injury to susceptible varieties. 



The author states that it may be successfully controlled by the application 

 of Bordeaux mixture the first season sprayed, and by the continued use of 

 this fungicide during successive seasons it can be almost completely eradicated 

 from an orchard in from four to six years. The 3:4: .TO formula of Bordeaux 

 mixture is recommended for use. Lime-sulphur solution was found less 

 effective than Bordeaux mixture for the control of apple blotch, but during 

 wet weather its use is recommended in place of Bordeaux mixture on account 

 of the tendency of the latter fungicide to russet the fruit. The work of eradi- 

 cating the disease can be hastened by cutting back trees and the commercial 

 value of the fruit correspondingly increased. 



The control of fire or pome blight, AT. H. Lawrence (Bien. Rpt. Bd. Hort. 

 Oregon, 12 (1911-12), pp. 107-109). — A description is given of the bacterial 

 blight of apples and pears, and attention is called to the necessity for organized 

 effort for its control. 



Treatments for fruit tree diseases, P. Perronne (Prog. Agr. et Vit. (Ed. 

 VEst-Ccntrc), 35 (1914), ^'o. 2, pp. 57-60).— The author details chemical and 

 surgical treatments claimed to prove beneficial under given conditions in case 

 of peach rust, and black s}oot of pear trees. 



A new disease of pear, P. Passy (Jour. 8oc. Nat. Hort. France, 4- ser., 14 

 (1913), May, pp. 288, 289; Rev. Hort. [Paris], 85 (1913), No. 11, pp. 252, 253).— 

 A description is given of a disease of pear trees which has been recognized for 

 about a dozen years. 



The cause is not definitely known, although it is believed possibly to be bac- 

 terial in its origin. The progress of the disease is shown in the checking of 

 development of the shoots in midseason, at which time the epidermis loses its 

 smooth appearance and takes on a purplish color, later becoming roughened. 

 The following year the branches showing signs of the disease are purplish in 

 color and rough, and in case of severe attack the leaves fail to develop. In 

 some instances the cracking of the epidermis is quite marked, the slits extend- 

 ing to a considerable depth. As is indicated above, little is known regarding 

 this disease, which is still under observation. 



Treatment of court-noue with tar, J. Bertkand (Prog. Agr. et Vit. (E'd. 

 VEst-Ccntre), 35 (1914), No. 3, pp. 80-8^).— This is mainly a favorable discus- 



