248 



counties and in 1933 in 11 counties additional, making a total known oc- 

 currence in 17 counties. They are widely distributed over the southern 

 two-thirds of the state, as shown on Map 108, suggesting a wide-spread 

 occurrence of the disease in that section of the state. 



Its seriousness in 1923 is indicated by some of the field notes. In 

 Sangamon county certain patches showed from 10 to 40 per cent of the 

 plants infected ; in Effingham county we have a record of a 10 per cent 

 infection, and a similar record for two patches in Warren county ; in 

 Lawrence county 60 per cent infection was recorded ; from Union and 

 Alexander counties there were several reports of 1 to 2 per cent, one 

 from Alexander of 5 per cent ; and another from Clinton county of 20 per 

 cent ; and in Union county in some of the larger fields 20 to 100 per cent 

 of the plants were infected. 



Control in this case is the same as that outlined under cantaloupe. 

 (See p. 244.) 



Anthracnose 

 Caused by Colletotrichum lagenarium (Pers.) E. & H. 



Anthracnose of cucumber is similar to that of watermelon and canta- 

 loupe and is caused by the same fungus. 



Doolittle's report of it in Illinois in 1922 is the first record of its 

 presence in the state. In 1923 it was found in Union county, where in 

 many instances it appeared to be a troublesome disease. It was especially 

 prominent near Dongola and Balcom, where the percentage of infected 

 vines varied from 20 to 100. Observations made on about 6 acres in 

 this region indicated the probability of considerable damage resulting from 

 the attack. 



Control is to be had through seed treatment and spraying, as indicated 

 for watermelon anthracnose (p. 247). 



Mosaic 



Mosaic, next to wilt, is probably the most important disease cucumber 

 growers have to contend with in Illinois. While the cause of it is un- 

 known, its appearance is familiar to most growers, who know it not only 

 as mosaic, but also as "leaf-mottle" and "white-pickle." 



Bierbaum reported the disease in Union county in 1922. and in 

 1933 it was found in Union, Sangamon, and Macon counties. Wherever 

 found it has been serious. In Alacon county 30 per cent of the plants 

 seen were diseased. In Union county in many fields from 50 to 75 per 

 cent of the plants were diseased, and in one instance 80 per cent of the 

 cucumbers picked for pickling showed its presence. In Sangamon county 

 the percentage of infected plants varied from 15 to 70 per cent. 



Control consists in keeping in check such insects as spread the dis- 

 ease from plant to plant, and in eradicating wild cucumbers and milkweed 

 plants from the neighborhood of the field since both of these are subject 

 to the disease and serve to introduce it into the cropped fields. 



