EFFECTS OF THE MODIFIED HOT-WATER TREATMENT ON 
GERMINATION, GROWTH, AND YIELD OF WHEAT 1 
T 
By V. F. Tapke 2 
Pathologist, Office of Cereal Investigations , Bureau of Plant Industry , United 
States Department of Agriculture 
INTRODUCTION 
The loose smut of wheat ( Ustilago tritici (Pers.) Jens.) (PI. 1), according to 
estimates compiled in the Plant Disease Bulletin 3 for the years 1917 to 1921, in¬ 
clusive, caused an average annual loss to farmers of the United States amounting 
to more than 11,000,000 bushels. Recommendations for control of this disease 
in this country have been confined to treatment of the seed by the modified hot- 
water method. In comparison with other standard cerealrseed treatments, 
however, this method is considerably more tedious to apply and also requires 
more labor and equipment, facts which doubtless help to explain why its adoption 
by the individual farmer has been limited. In 1918, R. G. East, county agri¬ 
cultural agent in Shelby County, Ind., in an attempt to make the modified hot 
water treatment more practicable, established a central or community seed- 
treatment plant at Shelbyville, Ind. The Division of Botany, Department of 
Agricultural Extension, of Purdue University, the Office of Cereal Investigations 
of the United States Department of Agriculture, and the Farmer’s Association of 
Shelby County, Ind., cooperated with Mr. East in this endeavor. The community 
system became instantly popular and within two years, according to Pipal 
(10) 4 , 20 plants were operating in Indiana. A few plants also were in use in 
Virginia. 
Pipal (10) has described the community system employed in Indiana, where 
two types of treating plant are used. One type operates in connection with a 
creamery, cannery, mill, or other establishment where a supply of live steam and 
suitable tanks are available. Here the farmers bring their grain and treat it 
in small quantities in sacks. The other type employs a special treating drum 
and tank for administering the 10-minute treatment, a devifce first used in 1918 
by R. G. East. The drum is built of heavy, small-meshed wire or perforated 
sheet iron .and is large enough to accommodate five bushels of soaked grain. It is 
equipped with a hoisting device operated by hand or motor. A crank also is 
provided to revolve the drum when it is lowered into the water. As it turns, the 
wheat tumbles over, thus insuring its uniform contact with the hot water. Fol¬ 
lowing the treatment, the grain is spread out to cool; later it is resacked and 
returned to the farmer. In order to defray the expenses of the community plant 
i Received for publication Dec. 18, 1923. 
* The writer makes grateful acknowledgment to Drs. W. H. Tisdale, H. B. Humphrey, and C. R. Ball 
for helpful criticisms of the manuscript, and to the agronomists in the wheat projects in the Office of Cerea 1 
Investigations for supplying many of the seed samples used in the experiments. 
* U. S. Department of Agriculture, Bureau of Plant Industry, Plant Disease Survey. Estimate of 
crop losses / due to plant diseases, 1917 . wheat. U. S. Dept. Agr. Bur. Plant. Indus. Plant. Dis. Bui. & 
3-4. 1918. (Mimeographed.) 
- Crop losses from plant diseases in the united states in 1918-1921. wheat. U. S. Dept. 
Agr. Bur. Plant. Indus. Plant. Dis. Bui., Suppl. 6: 190-191; IS: 309-310; 18: 318-319; 2k 490-491. 1919-1922. 
(Mimeographed.) 
* Reference is made by number (italic) to “ Literature cited,” p. 97. 
Journal of Agricultural Research, Vol. XXVIII, No. 1 
Washington, D. C. April 5,1924 
Key No. G-362 
( 79 ) 
