A Test of Indiana Varieties of Wheat SEBvDrtORe^B 

 Fungous Infection. •uiianf) ni 



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Geo. N. Hoffek. I ,..,.)]-ihb Y.I'iiJ')n 



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'Indiana grows annually more than 2,500,000 acres of wlieat. The aver- 



V acre. — Cir. 

 di suiY/oIlol 



age yield for the past ten years has been le>.l bushels per acre.' — Cir. No. 



23, Purdue University Agr. Exp. Sta. 



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The economic significance of any factor which plays a part m causing 



c decrease in the quantity of the yield, even though this ' decrease may be 



represented by a fractional part of one per cent, of the yield, is'cmiskTerabTe. 



The mere presence, then, of internally infecting fungi in the wheat seed 



studied in the laboratory may be indicative of very important prbblems m 



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the field. 



In Bulletin No. 203 of the Ohio Agricultural Experiment WiAt\o\\!^Ti 

 I'. Manns has described a method for detecting fungi internllTiy inrecting 

 wheat and other small grain. The method in brief, consists in sterilizing file 

 outside of the grain by means of a solution of corrosive sublimate in 50 per 

 cent, alcohol and then placing the seeds in sterile petri dishes on agar-agar. 

 This allows germination of the plant embryo when viable. Cultures 

 or growths of the fungi surviving internally in the seed develop at the 

 same time. The fungi in these cultures can then be identified. 



The results of laboratory tests at the Ohio station "show an amazing 

 amount of disease transmission in seed wheat as well as the proof of scab 

 infection by both germinatmg and dead wheat kernels." A study of field 

 conditions showed "that many seedling wheat plants were killed by the scab 

 fungus (Fusarium roseum) conveyed in the seed or retained by the soil." 

 This verified the laboratory conclusions. 



In the report of the botanist of the North Dakota Agricultural Experi- 

 ment Station for lull, Dr. H. L. Bolley concludes from the results of numer- 

 ous tests of seeds that "our experiments, taken as a whole, tend to prove 

 definitely that the soil is not often materially depleted, but that the deteri- 

 oration in yield and quality of grain is more specifically to be assigned to 

 troubles caused by internal seed infection and soil infection." 



7—1019 



