188 Proceedinf/s of Indiana Academy of Science. 



Diseases Arranged isy Hosts. 



APPLE. 



Blcitcli (Fig. 1) caused by PliylloHiicta solitaria was severe on the sus- 

 ceptible varieties tliroughout tlie soutliern half of the state and was noted 

 at Peru by F. P. Cullinan, in DeKalb county by C. T. Gregory, and as far 

 north as Delplii, Columbia City. Steuben county and Lake county by C. L. 

 P.nrkholder. Tlie Mann and Maiden Blush should be added to the list of 



Fig. 1. Apple blotch. 



susceptible varieties in the 1919 report. At Mitchell. Prof. Greene noted 

 abundant fruit infection June 10 and petiole lesions were noted at Moores- 

 ville June 11. Unsprayed Northwestern Greenings at Knightstown showed 

 as high as 91 per cent fruit infection and 39 per cent petiole infection and 

 at Mooresville as high as 97 per cent fi'uit infection and 83 per cent petiole 

 infection. Counts made by Burkholder in Clark county showed 97 per 

 cent fruit infection on unsprayed Ben Davis trees. Good control was se- 

 cured with Bordeaux sprays 2. 4 and 6 weeks after petal fall, while sulphur 

 dust, Bordeaux dust and dormant sprays were ineffective. 



Scab (Fig. 2) caused by Vciifiiria inaequalis was especially severe in tlio 

 southern part of the state but rather light in the northeast quarter of the 

 state where its ravages are usually the worst, according to reports by 

 Burkholder and Cullinan. Burkholder reports very little scab on unsprayed 

 cheek plots in AVliitley county except upon Ben Davis and Fameuse. On 

 the other hand, the same observer reports that scab was more severe in the 

 region between Crawfordsvillo and the Ohio river than in the preceding 

 three seasons. At Mooresville. June 25, scab was noted to be abundant on 



