150 



Ii.i.iNois Natlrai. History Survey Bulletin 



Vol. 27. Art. 2 



prevented the disease from spreading over 

 the whole soft wheat area. 



Other activities of the Section during 

 the l*^20's included warning cotton grow- 

 ers in southern Illinois of the diseases to 

 be encountered, discoverinjx and destroy- 

 ing the only known instance of alfalfa 

 infestation by the stem nematode, and 

 collecting data on the prevalence and de- 

 structiveness of stinking smut of wheat. 

 By 1923 it had been determined that 

 165 diseases affecting 44 different crops 

 were present in the state. In that year 

 the estimated reduction in yield of Illinois 

 wheat caused by five diseases ( leaf rust, 

 stem rust, stinking smut, loose smut, and 

 scab) was 7.712.800 bushels, valued at 

 >I 1.837.000. 



In most years of the past decade the 

 estimated annual losses from diseases of 



Illinois wheat have been 5,500,000 to 

 7,150,000 bushels. The greatest loss in 

 a single vear. 7,150.000 bushels, valued 

 at 515,158,000, occurred in 1950. In 

 1953, a year of minimum loss, the esti- 

 mated reduction in vield was onlv 368,- 

 800 bushels, valued at S586,400. 



The estimated annual losses resulting 

 from diseases of corn usually are greater 

 than the losses resulting from diseases of 

 wheat. In the past decade the lowest esti- 

 mated reduction in corn yield. 54.250,000 

 bushels, valued at S82.450.000. occurred 

 in 1952 and the highest estimated reduc- 

 tion in vield, 168.100.000 bushels, valued 

 at SI 98.358,000, occurred in 1949. The 

 average annual estimated reduction in 

 yield of corn in Illinois during the past 

 decade was 90.626.100 bushels, valued at 

 SI 12.139.072. 



Homemade m... ,. . . „;.,.^t 25 years ago by plant pathologists of the Illinois Natural 

 History Survey to demonstrate effectiveness of chemical treatments in control of seed-borne dis- 

 eases ot small grains. 



