374 DISEASES OF ECONOMIC PLANTS 



utes at 54° C. (129.2° F.). Above 54° C. (129.2° F.) 

 there is no safe margin. If the temperature falls slightly 

 below 52° C. (125.6° F.), the time of treatment should be 

 increased in proportion. A temperature lower than 51° C- 

 (123.8° F.) is not effective. In treating wheat, if the 

 temperature should rise above 54° C. (129.2° F.) or fall 

 below 52° C. (125.6° F.), the time for immersion must be 

 diminished or increased accordingly. Under no circum- 

 stances should a temperature of more than 55° C. (131 ° F.) 

 be allowed. Temperatures below 51° C. (123.8° F.) are 

 ineffective." A reliable thermometer is necessary, since 

 the use of an inaccurate instrument may result in injury to 

 the germinating power of the grain or in failure to prevent 

 the smut. 



Two men working together can easily treat one bushel 

 of grain an hour, or enough seed in one day to sow a seed 

 plat of from 6 to 10 acres. The seed may be dried by 

 spreading it out in thin layers not over 5 cm. in depth 

 on a clean granary floor or on canvas, and shoveling or 

 raking it from time to time. It should not be allowed to 

 sprout. Care must be taken to prevent freezing of the 

 grain when it is moist, as this will impair germination. 

 • Seed treated as indicated may be planted as soon as it is 

 sufficiently dry to run freely through the drills, making al- 

 lowance for the swollen seed. Before sowing, the seed 

 should be tested for germinating power, and a correspond- 

 ing increase in the rate of seeding be made. 



The seed plat may be maintained from year to year, or as 

 long as any smut is present in the grain fields. Seed ob- 

 tained from the treated seed plat does not have to be treated 

 the following year. 



