231 



paign county, in 1921. BurrilF records its presence in Wabash, Union, 

 and Champaign counties. 



The present known occurrence of powdery mildew on cultivated 

 grape is shown on Map 83 to include 8 counties, but it is probably much 

 more widely distributed. 



The usual sprays suffice for its control. 



Brambles 



The brambles include raspberries, blackberries, loganberries, and 

 dewberries. Commercial production of these fruits, while of consider- 

 able importance for the state, is not scattered uniformly over the state, 

 but appears to be localized in small areas of concentrated production. 



All the brambles are subject to the same diseases, but one disease 

 may commonly be severe on one bramble and mild on another. These 

 diseases will, therefore, be discussed from the standpoint of the disease 

 rather than the host, with appropriate notes on susceptibility under each. 



Anthracnose 



Caused by Plcctodiscclla vencta Burk. 



Anthracnose is especially a disease of the raspberry, although black- 

 berries, dewberries, and loganberries are subject to it; but besides the 

 raspberry only the blackberry appears to suffer from it severely. 



Anthracnose appears at first on the canes as small, purplish, slightly- 

 raised spots which increase in size, their centers becoming cracked and 

 dull gray. They are usually oval with a raised purplish border, but when 

 numerous they grow together, forming large, irregular, grayish cracked 

 areas on the canes. Similar spots occur on the petioles, leaf ribs, and 

 berry-stems ; and more rarely small purplish spots appear late in the 

 season on leaves 



Damage done by anthracnose is limited almost entirely to canes, but 

 by direct injury to them the entire plant is weakened. Losses from 

 this disease have been variously estimated. Anderson- re])orts that in 

 1908 the loss was 8 per cent of the crop. In 1923 it was estimated at 

 3 per cent. 



The earliest Illinois record is in a collection made by Charles 

 Wheeler'' at I-lvanston, Cook county, in IcS.Sj. Another collection was 

 made by F. S. Earle in Union county in 1884. 



At the i)resent time the disease is known to occur in 45 counties, 

 most of which lie in the northern half of the state, as shown on Map 84. 

 Anthracnose appears, however, to have an extensive distribution, includ- 

 ing all parts of the state, and an examination of gardens would undoubt- 

 edly show its occurrence in every one of our 102 counties. 



'Bui. 111. .'St. I^b. Nat. Hist. 2:407. 1887. 



'III. Agr. Kxpr-r. CIrc. 211: 114. 1920. 



> Ellis. .1. li.. .'inil EvLihJiit. B. XI. Joiirn. Mvc. 3: 12fl, 1SS7. 



