Hot Water Treatment for Smut 315 



THE PRESENT STATUS OF THE HOT WATER 

 TREATMENT IN INDIANA.^ 



C. T. Gregory, Purdue University Ag-ricultural Experiment Station. 



The first application on the farm of the hot water treatment of 

 wheat for the control of loose smut was made in Indiana in 1917 by 

 six men in five counties. Since that time the number has steadily in- 

 creased until in 1921 there were about 850 farmers in 50 counties who 

 treated their wheat. Moreover, the influence of the treatment has been 

 spread by the ever increasing supply of seed from treated fields. For 

 example, in Shelby County, where some of the pioneer work was done, 

 there is a supply of 25,000 bushels of such seed this year (1922) ; Han- 

 cock County has over 2,000 bushels; Gibson County, 3,000 bushels; 

 Posey County, 5,000 bushels; and Wayne County, 4,900 bushels. It is 

 reported that there are 29,000 acres in Knox County planted with seed 

 from treated fields. 



As is usual when a laboratory control method is first applied on 

 the farm many unforeseen changes were necessary to make the method 

 entirely practical. The particular changes that have been made can 

 best be discussed under the different phases of the treatment. 



1. Presouking. It has been proven that presoaking is one of the 

 essential steps in the treatment. The early recommendation, to soak 

 the wheat in cold water for eight hours, is perfectly proper but under 

 farm conditions this time is too long because the treating usually begins 

 about 9 A.M. making it necessary to begin soaking the seed at 1 A.M. 

 Investigations showed that four hours presoaking was sufficient and 

 that 12 hours soaking is dangerous because the seed is quite apt to 

 germinate and thus be rendered much more susceptible to injury by the 

 treatment to follow. A peculiar mistake in the presoaking recommenda- 

 tions was made in Porter County last year. The farmers thought that 

 any four hours previous to treatment would do and they soaked the 

 wheat during the previous afternoon. Promptly at the end of the time 

 they removed the sacks from the water but allowed the soaked wheat 

 to stay in the sacks until the following morning thus permitting suffi- 

 cient germination to prevent successful treatment. 



Not more than one bushel of dry wheat should be soaked in a two 

 bushel burlap sack because it swells to almost twice its original bulk. 

 If the sacks are too full the seed will soon become packed and either 

 burst the sacks or, as sometimes occurs, the tight outer layer excludes 

 the water and the wheat in the center is not properly soaked. Because 

 of this propensity of the seed to swell and tightly pack, the sack should 

 be laid on its side in the water, rather than on end. 



2. The Treatment. At first a half bushel of wheat was treated 

 in a barrel of hot water, the temperatui-e being maintained by adding 

 boiling water from time to time. In Shelby County v;'iere large amounts 

 of wheat were treated this method was too slow and a rather ingenious 



' Contribution from the Department of Botany (Extension Division) of the Purdue 

 University Agricultural Experiment Station. 



"Proc. 38th Meeting-, 1922 (1923)." 



