19!) 



It is known to occur in 14 counties distributed widely over the 

 state, as shown on Map 25. 



Examinations made during 1922 in 13 fields distributed among 11 

 counties indicated that an average of 40 per cent of the stalks were 

 rusted, and similar examinations made during 1923 in 20 fields distrib- 

 uted among 1-1 representative counties and including 209 acres indicated 

 that an average of 90 per cent of the stalks were rusted, the diseased 

 leaf-tissue averaging 35.3 per cent on each infected plant and 31. ~ per 

 cent on all plants. 



No satisfactory means of preventing the occurrence of this disease 

 is known. 



Stem Rust 



Caused by Pucciiiia gramin'is Pers. 



Stem rust of rye is similar to the stem rust of wheat previously 

 described and is caused by the same fungus. In Illinois, however, it ap- 

 pears to be much less prevalent on rye than on wheat. 



Although this disease has undoubtedly been present in the state for 

 many years, it was definitely reported for the first time in 1918, when 

 it was collected in McHenry county. In 1922 it was found in 10 coun- 

 ties scattered through northern Illinois. Its known distribution, as 

 shown on Map 26, includes 16 counties, most of which are grouped in 

 the northern part of the central section of the state. 



Aside from the eradication of the common barberry, no satisfactory 

 methods of control are known. 



Ekgot 

 Caused by Claviccps purpurea (Fr.) Tul. 



Ergot attacks individual grains in the rye heads, causing them to 

 become greatly enlarged and distorted. The disease does not often cause 

 much loss, since it is seldom present in fields, and usually only a few 

 grains in a head are diseased. The greatest danger from this disease 

 lies in the poisonous nature of distorted grains. Seriously affected rye, 

 or wheat that has become mixed with rye, should not be fed to stock 

 when this disease is present in any ([uantity. 



Few reports of the presence of ergot in Illinois have been made. 

 In 1919 it was present in several fields in Carroll county, and the in- 

 fection is said to have been fairly heavy but appears to have been con- 

 trolled by a change of seed. In 1923, and for several years before, there 

 were light infections in a few fields in Ogle county. Usually the most 

 serious infections are to be found on rye growing in wheat. An ex- 

 ample of this is found in observations made in Hancock county in 1923. 

 Several fields of wheat badly mixed with rye showed from 30 to 90 per 

 cent of the rye heads infected, with from 10 per cent to CO per cent of 

 the grains diseased. Aside from the loss in production, such grain would 

 be wholly unfit for feeding purposes. 



