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In some cases this disease was so destructive that the crop was plowed 
under. In other fields a fair yield was secured. In order to prevent a 
spread of the disease, state authorities compelled the burning of the straw 
from the infested fields and a thorough disinfection of the grain in formal- 
dehyde. None of the grain was allowed to be used for seed. Growers were 
advised not to plant wheat in these fieids for several years. The cause 
of the disease has not been determined. 
In connection with the rather careful statewide search made for the 
above disease, a very considerable amount of frost injury to wheat was 
found. This was evidenced by a shriveling and brown discoloration of the 
stems just above the nodes. 
Wheat scab caused by Gibberella saubinetii was the most serious wheat 
disease and was an important loss-producing factor this season. As a result 
of the federal cereal disease survey, scab was found in 442 or 74% of the 
596 fields examined with an average incidence of 17%. James Dickson, in 
charge of this survey, reports cases of infection as high as 90% in Orange 
and Posey Counties. Pipal reports authentic cases in Vanderburg, Knox, 
and Posey counties where the crops were not even harvested and he esti- 
mates that there was a 50% loss in badly infected fields in general. 
Since recent investigation indicates that the wheat scab fungus lives 
over winter on corn stalks the following observations are of interest. Pipal 
reports an instance of a farm near Martinsville where 55% scab occurred 
in wheat following corn and only a trace in the other field on fallow ground. 
On another farm the corn stalks were carefully removed from one acre in 
a large field planted to wheat. This acre later showed 3% scab as compared 
with 10% in the rest of the field. From Dickson’s report it appears that 
out of the 13 fields examined in Hancock County, the percentage of scab 
ranged from 5 to 45% in the six fields where wheat followed corn, with an 
average of 20%, while in the seven fields which were not in corn in 1918, 
the percentage of scab ranged from 5 to 75% with an average of 29%. 
Among the latter is a case of 60% scab following clover and another of 15% 
following wheat. From the same report it further appears that in the 10 
fields surveyed in Posey County, there was an average of 77% scab in the 
four fields which were in corn in 1918 and an average of 65% in the other 
six fields. Furthermore, in the 10 fields surveyed in Orange County, there 
was an average of 45% scab in the six fields in corn in 1918 and 15% in 
the other four fields. The evidence therefore is not conclusive and factors 
other than the corn must be considered. It seems quite likely that other 
plant residues are also of importance as a source of infection. Dickson 
gives as his opinion that the two important factors are the abundance 
of the parasite, and the presence of organic matter such as plant residues 
on the soil for the propagation of the parasite. He intimates that the 
preparation of the soil is as important as the crop rotation utilized. <Ac- 
cording to Hoffer, seed from diseased heads yields weak plants but does 
not constitute an important means of dissemination of the scab fungus. 
1Humphrey, Harry B. and Johnson, Aaron G. Take-all and flag smut, two wheat 
diseases new to the United States. U.S. Dept. Agr. Farmers’ Bul. 1063:1-8. 1919. 
