25S ILLINOIS STATE ACADEMY OP SCIENCE 



Impatiens: Rust (Puceinia impatientis Arth.) was 

 found in White, Hamilton, Edwards and Jefferson coun- 

 ties. The first collection was made at Texico, June 21. 



Lilac: Powdery mildew (Microsphaera alni (Wallr.) 

 .Salm.) resulted in some defoliation. The earliest collec- 

 tion was made June 24 at Whittington. 



Rose: Leaf spot (Diplocarpori rosae Wolf.) was com- 

 mon throughout the state on cultivated plants. 



Powdery mildew (Sphaerotheca pannosa (Wallr.) 

 Lev.) was present over the southern half of the state on 

 cultivated roses in epidemic form. Considerable defolia- 

 tion resulted later in the season when the hot, dry weath- 

 er appeared. 



Symphoricarpos: Powdery mildew (Microsphaera 

 alni (Wallr.) Salm.) was abundant everywhere. The ear- 

 liest collection was made July 3, in Edwards county. 



Virginia Creeper: Leaf spot (Guignardia bidwellii 

 (Ell.) V. & R.) was abundant throughout the state. 



Zinnia: Powdery mildew (Erysiphe cichoracearum, 

 DC.) was collected August 31 at Chrisman. This is the 

 first report of this fungus on this host for Illinois. 



SUMMARY 



The outstanding features of the year appear to have 

 had a direct connection with climatological conditions. 

 The greater number of diseases were either about the 

 same as in an average year or caused less than the usual 

 crop reduction. Noteworthy conditions included the ear- 

 ly appearance of brown rot as a blossom and twig blight 

 on peaches, the widespread epidemic of powdery mildew 

 on clover and cultivated roses, the serious losses oc- 

 casioned by leaf rust in the winter wheat area, the abun- 

 dance of crown rust on oats, and the unusual and des- 

 tructive outbreak of the wilt diseases of cantaloupe and 

 watermelon. 



