182 



in that field, and the average percentage of infected heads in the fields of 

 the state represents the loss for the state. Complete data are not al- 

 ways obtainable, but estimates indicate losses varying from a trace to 

 6 per cent of the state crop. 



There is a further loss from this disease through dockage when 

 smutted grain is sold. The presence of stinking smut in threshed wheat 

 tends to give it an offensive odor. When the amount of stinking smut 

 is great the odor is so pronounced that it reduces the value of the grain 

 for milling purposes, and most dealers impose a dockage, or reduction 

 in price, upon such wheat. Dealers often refuse to purchase badly smut- 

 ted wheat. 



The occurrence of stinking smut in Illinois is shown on Map 5. 

 Its distribution coincides with regions devoted to wheat production, but 

 it is rarely found in the northern or southern thirds of the state. 



Examinations of fields in many parts of the state in 1923, the re- 

 sults of which are given in Table 10, suggest the field-by-field preva- 

 lence of this disease and indicate the severity of infection and loss on 

 the average farm. An average infection of 4.08 per cent was found 

 in 1140 acres distributed among 22 counties. All degrees of infection 

 were found. 



While the acreage examined is not large in comparison with the 

 total wheat acreage of the state, if 20 acres be taken as the average 

 amount of wheat per farm it may be inferred that data from 57 aver- 

 age farms are included. These are widely distributed over the state. 

 and may be considered as representative of conditions of infection to be 

 found on the average farm; Not every wheat fieM measured up to the 

 average amount of stinking-smut infection, but other fields showed suf- 

 ficiently greater amounts to bring the average infection for each field 

 up to 4.08 per cent. 



The yield per acre of wheat for the entire state for 1923 is estimated 

 at 18 bushels. At this rate the 1140 acres examined would yield 20.520 

 bushels, but this is less by 4.08 per cent than it might have been without 

 stinking-smut infection. The yield from this acreage with stinking smut 

 absent would have been 21,111 bushels; hence there is an apparent reduc- 

 tion in yield of 861 bushels which, when distributed among the 57 average 

 farms represented, gives a loss in yield of 15.1 bushels per farm. With 

 slinking-smut infection absent the individual farmer might have secured 

 the same yield from 19 l/(> acres that he was able to secure from 20 acres 

 with stinking smut infection present: or had he chosen to plant 20 acres 

 free from stinking-smut infection, he might have secured a yield of 375 

 bushels in place of 3G0 bushels. 



Mention has already been made of a cash loss in marketing smutted 

 wheat. This loss takes the form of a dockage in the price, which amounts 

 in practice to a reduction in grade. When wheat is offered for sale it is 

 graded, and the current market-price for the grade applied. Assuming 

 that a load of wheat grades "Hard Red No. 1," should stinking smut he 



