DISEASKS OF PLANTS. 547 



Furtlier iiivestlfrations arc to Itc carrii'd <iii cm a nunihor of lines with tliis 

 (11 sea so. 



Some apple leaf-spot fungi. ('. P. IIaktlky {Scicncr, n. set:, 2H (lOOS), 

 .\u. 701), t>P- lo^-l ')!>). — The author reports studies of leaf spot of apples, in 

 which 15 species of fungi were found iiresent, only 4 being coniuiou enough to 

 indicate any economic importance. These were Corynvum foUicohim, Coniothy- 

 riinn iiirhin, an undescrihcd species of Tuberculariie, and Spho'roiifii.'i malonun. 



Studies were made with imre cultures of ('. iiirinn, and the results of inocula- 

 tions indicate that it is a facultative or wound parasite only able to produce 

 spots on apple leaves provided it has killed or injured tissues in which to get 

 a start. It jirobably causes a considerable amount of leaf spot, but this has 

 not yet been demonstrated. The fungus was found to grow readily on deiid 

 twigs, and this led to its further study. A mori)liologically identical species was 

 found on dead twigs of a quince bush, and pure cultures were successfully 

 inoculated on apple leaves, producing the characteristic appearance. Later 

 the fungus was found on dead apple twigs, and it is possible that it winters in 

 this way. The author was unable to find fruits of the fungus on any fallen 

 leaves during the winter or spring. 



Inoculation e.\]tcriments were also made with C. foliicoliun with similar 

 results, the Coryneum appearing even less actively parasitic than the Coni- 

 othyriuni. 



A leaf-spot fungus of the apple, J. L. Sheldon (Torreya, 8 (WOS), No. 6, 

 1)1). l.i'.i-l'il ). — During the past 5 years the author has been making a study 

 • )f the causes of defoliation in the apple orchards of West Virginia, and during 

 this time has examined hundreds of leaves. As a result he has found that the 

 worst defoliated orchards showed that the fungi hitherto associated with de- 

 foliation were either not i)resent or when present did not bring about defolia- 

 tion. There was, however, a fungus belonging to the family Tuberculariae 

 universally present iu the orchards and so plentiful that the lower branches 

 of some of the trees were nearly defoliated, the remaining leaves being brown 

 and crumpled. 



A study of the fungus showed that it was an undescribed species, and the 

 author gives a technical description of it under the name JUositorUun mali- 

 piliorum n. sp. The sjiots caused by this fungus are said to be different from 

 those caused by any other leaf spot of the a|tple and can be readily recognized 

 even when the fungus is not in fruiting condition. In general, the spots are 

 nearly circular, from 5 to 15 nun. in diameter, often coalescent. The spots are 

 brown (»r mottled gray in color, the colors being more or less concentrically 

 arrangfil. In the center of S(jme of the spots is to be found a small gray or 

 whitish spot, causiHl usually by the infection of the leaf by some other fungus. 

 The larger and encircling spots are due to a secondary infection by the fungus 

 under considci'ation. 



Apple leaf spot, F. J. Chittenden {-Jour. Roy. Ilort. Soc. [London], ,id 

 (lUOS), \o. 2, PI). .'jOO-'jII, flOH. 3). — A descri|ition is given of the blotching and 

 torching of ai>ple leaves, due to the fungus Cltnlospoiinni licrhtirum. This 

 disease is sjiid to have been e.xtremely prevalent during the season of 1907, the 

 wivather conditions being such as to cause a somewhat abnormal growth, which 

 HMulered the foliage subject to tlie attack of fungi. 



From an investigation of a large number of varieties, the author linds that 

 some varieties are a]»|)arcntly more liatiie to the .-ittack of this fungus than 

 others. The best method of pn-vention, .so far as known, lies in the checking 

 of the gcrnunation of the fungus by means of applications of dilute Hordeaux 

 nii.\ture. 



