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Leaf Spot 

 Caused by Mycosphacrclla grossulariae (Fr.) Lind. 



The leaf spot of currant and gooseberry is, like anthracnose, chiefly 

 a leaf disease. While both fruits are commonly subject to it, currants 

 usually suffer the more severely. 



It appears on the leaves as spots, more or less circular in outline, 

 from one eighth to a quarter of an inch in diameter, and with a dark 

 reddish or brownish margin, within which is an area of dead, brown 

 leaf-tissue, over which a number of tiny black dots are scattered. In- 

 jury takes the form of a yellowing and dying of the leaf, followed by 

 early defoliation. 



The larger size of the spots, the central dead area, and the numerous 

 tiny black dots serve to distinguish leaf spot from anthracnose. 



Not many early reports of this disease in Illinois appear to have 

 been made. At present it is known to occur in ;50 counties, which are 

 grouped in three districts, as shown on Map 92. In the north, leaf spot 

 has been noted in 5 counties and a majority of the reports show that it 

 occurred in this region especially on red currant. In central-eastern 

 Illinois reports from 4 counties note its occurrence especially on the 

 flowering currant. In the southern tip of the state leaf spot appears 

 commonly prevalent and abundant through 20 counties. In this region 

 gooseberries and currants are both commonly found diseased, though 

 here there is again a majority of reports on currant. 



For control of leaf spot, the same application as for anthracnose 

 will be found effective. 



Powdery Mildew 



Caused by Sphacrothcca mors-tivac (Schw.) B. & C. 



Powdery mildew is of less importance than leaf spot. Both cur- 

 rant and gooseberry are subject to its attack, but it is more frequent or 

 gooseberry. 



It appears, like other powdery mildews, as a white, powdery growth 

 over the leaves. Berries and young shoots are often attacked. The in- 

 jury consists in stunting the growth of leaves and shoots, and in dis- 

 liguring the berries to the extent of making them unsalable. 



Powdery mildew has been known to occur in Illinois since 1881. 

 when it was found in McLean county, and it has since been reported in 

 La Salle, Pulaski, and Gallatin counties. 



It can be controlled by the use of lime-sulfur (1-40) spray applied 

 when the buds open and at 10-day intervals thereafter until 5 applica- 

 tions have been made. A better spray, since no injury to the fruit re- 

 sults from its use, is potassium sulphid, one ounce in 2 gallons of water. 



