102O] DISEASES OF PLANTS. 753 



tlie success and reliability of this treatment as a fungicide, wliifh in this respect 

 is compared with Uiile sulpliur. General discussion ljrou;;lit out the resu ts of ' 

 the exiicrieiice of otliers wllli sulphur as used alone and in connection with 

 insecticides. 



A disease of pear, K. Fokx (Bui. Son. Path. V<;j. Fraiirr, 6 (1919), No. 5, 

 PI). 100, 102-10.'/). — Brief notes are t,'iven of pear twij? i)lifrht ascribed to Diplodia 

 (jriffoni. Remedial measures include removal of affected wood and a winter 

 co[)iter spray at 3 to 4 per cent, repeated at a strength of 1 per cent two or three 

 times after bloomin?:. 



Pear rust (R<pstelia eancellata) and Juniperus sal>ina, V. Ciiassu;nol 

 (BiiL Soc Path. Vcy. France, 6 {1919), No. 0, pp. IIG, 7.j.i).— Krief reference is 

 made to a case of apparent partial innnunity in a pear tree of unknown variety 

 to pear rust from ./. ■sahiiKi. 



Dendrophoina leaf blight of strawberry, II. \V. A.ndkkson {Illinoi.t Sta. 

 Bill. 229 {1920), pp. 127-136, figs. 3). — The author reports the occurrence during 

 the sunnner of 1919 of a serious leaf blight of strawberry in several localities 

 of Illinois and Indiana. At first it was thought to be an advanced stage of the 

 ordinary leaf spot, but a detailed study showed that the disease had entirely 

 dilVen'nt .symptoms. The lesions of the leaf blight in question, even in an 

 early stage, are said to be much larger than the mature lesions of the ordinary 

 leaf spot. In an advanced stage, the most connnon condition is a V-shaped dead 

 area extending from the nudrib or one of the larger veins to the tip or side of 

 the leallet. The young spots are uniforndy reddish-purple when they first ap- 

 pear and are almost circular in outline. As they enlarge the central area dies 

 and becomes brown. In 1919 the diseased areas were observed as early as June, 

 liut it was not known how nmch earlier they may appear. 



In a study to determine the cause of this leaf blight, the author isolated a 

 fungus, the morphology and life history of which are described. The disease is 

 said to be due to Dtndrophomn obscurans n. sp., a technical description of 

 which is given. No experiments for the contx'ol of the leaf blight have been 

 attempted, but it is believed that the practice of mowing the leaves of the old 

 vines and cultivating after harvest will reduce the amount of trouble from this 

 source. 



A rose graft disease, I. H. Vogel {Phytopathology, 9 {1919), No. 9. pp. 40S- 

 412, figs. 6). — A study is reported of a disease of rose grafts said to occur in 

 rather severe form at Council Bluffs, Iowa, in 1917. It was particularly destruc- 

 tive to certain varieties which are popular with rose growers. 



A characteristic symptom is the occurrence of lesions on the scion at or just 

 above the union, which results in the sudden wilting and death of young rose 

 grafts. The lesions usually encircle the scion within a few days so that the 

 death of the graft is sudden. Study of the disease showed that it was due to 

 Coniothyrium rosarum. Marked resistance is .shown by some varieties, while 

 others are specially susceptible to the fungus. The most satisfactory method 

 of control is believed to be the growing of resistant varieties. Where this Is 

 not possible, care should be exi-rcised in the selection of scions, which should 

 not be taken from rose houses in which the disea.se is known to exist. 



Tuberosities of chestnut and ranker of rose, E. FoEX {Bui. Soc. Path. Veg. 

 France, 6 {1919), No. 3, pp. 63. 68-71). — \n account is given of outgrowths of 

 Castanea rulgaris and of rose canker, associated with a fungus differing some- 

 what as to dimensions from Coniothyrium fuckelii. 



Winter injury to ornamental trees and shrubs, F. S. Buck {Ann. Rpt. 

 Pomoh and Fruit Groving Soc. Quebec, 1918. pp. .',7-53).— The winter of 1917-18 

 was exceptionally cold and dry for long periods and was corresiiondingiy abnor- 



