238 



At the present time this disease is known to occur in 85 counties, 

 the state-wide distribution of which is shown on Map 94. It is prob- 

 ably to be found everywhere throughout the state. 



It is so common and so generally injurious that the reduction in yield 

 has been estimated for several years past at between 10 and 13 per cent. 

 In 1921 a reduction of 10 per cent would have meant a loss from the 

 commercial crop of practically 17.300 crates or slightly more than 44 

 cars, equivalent to 6 crates per acre, or a reduction of the average acre 

 yield from 60 crates to 54. 



Control where necessary may be had by an application of Bordeaux 

 mixture before the blossoms open and again at intervals after harvest. 

 Cleaning off infected leaves when new plants are set also helps. 



Dendrophoma Le.\f-Spot 

 Caused by Dendrophoma obscurans (Ell.) And. 



A second leaf-spot, less common than the preceding, but sometimes 

 very injurious, produces rather large brown spots, surrounded by a dif- 

 fused darker brown or purplish border of considerable width. If the 

 attack is severe a large part of the leaf may be involved, considerably re- 

 ducing its eft'ective surface. 



The first reports of this disease in Illinois were made by Anderson 

 in 1920.^ Since then it has been seen frequently, and its present known 

 distribution is shown on Map 95. It is known to occur in 12 counties 

 widely distributed over the state. The district of most frequent occur- 

 rence, so far as now known, lies in central Illinois, and it is in this region 

 also that reports of greatest severity originate. 



Leaf Scorch 



Caused by Mollisia carliana (E. & E.) Sacc. 



This is a leaf .spot of strawberry of relatively infrequent occurrence. 

 H. W. Anderson^ first reported its occurrence in Illinois in Champaign 

 county in 1921 on certain varieties imported from Michigan. It has 

 not been reported from any other part of the state. 



Control of Fruit Diseases 



Diseases of fruits are chiefly controlled cither by spraying with suit- 

 able preparations or by the cutting out of diseased parts. Other 

 practices which are helpful have already been mentioned in connection 

 with the diseases for which they are effective. .\ combination of sprays 

 with insecticides is often useful as controlling the ravages of both dis- 

 eases and insects. 



■ Anderson. H. W. Dendrophoma loaf blight of Strawberry. 1\\. \ev. Exp. t=ta. 

 Bui. 229. 1920. 



2 Plant Disease Survey Bulletin. Supplement 20: Id. 1922. 



