168 Proceedings of Indiana Academy of Science 



two pear trees as sources of infection. G. W. Cochran was unable to 

 locate any active fire blight in the neighborhood of LaFayette. 



Blister canker caused by Nummularia discreta is of very consider- 

 able importance in central and southern Indiana, especially in the older 

 orchards of the Ben Davis variety. Its occurrence near Greencastle 

 has been j^reviously reported. Specimens were received from Posey 

 county and the disease is reported on Ben Davis in orchards in Brown 

 and Jay counties. Blister canker was found destructive on a few older 

 trees in an orchard in Orange County and in an orchard in Miami 

 Coimty it is causing serious injury to both Grimes and Ben Davis. In 

 the latter instance the disease has apparently followed winter injury 

 and is actively killing the limbs which were conspicuous this season 

 because of the yellow foliage and dwarfed fruit. On October 5, new 

 stromata were found under the lenticels in recently infected bark, and 

 many fresh stromata had burst through the lenticels producing star- 

 shaped ruptures. The nail-head stromata on the older parts of the 

 cankers are, of course, conspicuous and characteristic. Growers report 

 poor success with attempts to eradicate the disease by cutting-out meth- 

 ods. Howev^er, in certain orchards observed, blister canker has affected 

 only a few trees and determined efforts to eradicate such centers of 

 infection should be made. In case removal of all diseased wood is 

 impracticable it is advisable to .shave off the bark to prevent spore pro- 

 duction, as Anderson (111. Cir. 258) has recently recommended. 



Rust (Gyinnospor'angium jiiniperi-virginianae) was noted on the 

 foliage of York and Jonathan in Orange County, on Jonathan in Mor- 

 gan County, and on Wealthy foliage in Lawrence and Henry counties. 

 Serious difficulty with rust is reported from Brown county. The wide 

 prevalence of red cedar in .southern Indiana insures an annual rust 

 infection of the susceptible apple varieties and as a rule no eradication 

 of the cedars has been attempted. 



Powdery mildew (Podosphaera oxycanthue) was found very severe 

 on the young leaves of young Winesap trees at Vincennes, April 28, on 

 young sprayed Transparent and Carson trees in Morgan county on 

 May 12 by C. E. Baker, and in the fall on young trees in Lawrence 

 county. The wet weather of early spring and later summer probably 

 favored this disease. Burkholder reports that crown gall and hairy 

 root, due to Bacferinm tumefaciens, is often present on apple nursery 

 stock received by Indiana growers. 



This was an epidemic season for sooty blotch and fly-speck, caused 

 by Gloeodef! pomigena (7) and Leptothynum pomi. Burkholder reports 

 this trouble from Gibson and Pike counties and observed that an extra 

 spray applied about August 1, gave a good control. Cullinan did not 

 find the disease severe in sprayed orchards. In an unsprayed orchard 

 in Morgan County, this disease was noted Sept. 15 on Ben Davis, 

 Maiden Blush, Pewaukee, Grimes, Wealthy, Northwestern, Jonathan, 

 Indiana Favorite, and York. It is especially objectionable, of course, 

 on such light-skinned varieties as Grimes, Maiden Blush, and North- 

 western, and on York it was noted that the red coloration was absent 

 underneath the sooty blotches. 



The occurrence of a rather destructive rot of apples caused ap- 



