241 



Black Scurf 

 Caused by Rhizoctonia sp. 



This disease, which results in blackened, rotted stems, the wilting 

 and dying of young shoots, and aerial tubers, has been found but once in 

 Illinois, in July, 1922, near Ryder, Jefferson county. 



Infection arises from diseased tubers and from soil infection. Pre- 

 ventive measures include use of clean seed, crop rotation, and general 

 sanitary practices in field cultivation. 



Wilt 



Caused by Fusarlmn sp. 



The wilt disease results in wilting and stunting of the tops, death of 

 roots, and serious storage rots. It was found in 1923 in Lawrence county. 

 In a small field of Irish Cobber practically all the plants were diseased, 

 and it appeared that the loss would be severe. As a preventive meas- 

 ure, the use of infected tubers for seed should be avoided. 



Curly Dwarf, or Mosaic 



This disease, of unknown cause, results in stunted and variously de- 

 formed plants, mottled coloring of the leaves, and noticeably reduced 

 yields. It is probable that it is wide-spread in the state, but it has been 

 noticed thus far only in Carroll comity, where it was found in several 

 fields in 1923. Its history there indicated that it had been present for 

 several years. It is seed borne, and tubers for seed should be selected 

 from fields free from disease. 



Tomato 



The tomato is an important crop in Illinois. In 1921 there were 

 only 9 states having a greater acreage, and in the same year the total 

 commercial crop was exceeded by only 8 states. During the years 1918- 

 1921 the tomato acreage in the state varied from T,()(;4 to 9,355 acres; 

 and the yield, from 24,724 tons to 59,5S4 tons. This crop is used for 

 local consumption, for immediate distribution and sale, and for canning 

 and the manufacture of tomato products. 



In addition to the commercial crop of the state, growers maintain 

 small patches in the neighborhood of towns, from which the local seasonal 

 market is supplied. 



The tomato is subject to a variety of diseases, several of which arc 

 similar to those of the potato. 



Early Blight 



Caused by Altcrnaria solani (E. & M.) J. & G. 



Early blight is one of the commonest and most wide-spread of tomato 

 diseases in Illinois. It causes numerous small, more or less angular, con- 



