CEREAL PESTS PARASITIC FUNGI 521 



In Washington it is found that salt added to the cop- 

 per sulfate solution increases its effectiveness. In both 

 Oregon and Washington the viability of the treated seed 

 is commonly observed to be much lower than that of 

 untreated seed. For this effect a possible explanation is 

 suggested in another place (434). It seems prob- 

 able, however, that the condition more commonly favor- 

 ing such injury is the cracking or other damage suffered 

 by the grain in thrashing. At the Washington Experi- 

 ment Station, experiments show that machine-thrashed 

 grain is injured more as to germination than hand-thrashed 

 grain. The kernels are cracked and broken by the 

 machine, which allows the fungicide to injure them more 

 than the sound kernels. The same difficulty as to treat- 

 ment with copper sulfate is found in Germany. 



564. Steeping in the fungicides. The copper sulfate 

 solution, for steeping, is prepared by dissolving 5 pounds 

 of the sulfate crystals in 50 gallons of water. Time may 

 be saved by tying the 5 pounds of crystals in a wide- 

 meshed bag and suspending it overnight in 50 gallons of 

 water. Hot water will dissolve the crystals more quickly 

 than cold water. The formalin solution is prepared in the 

 proportion of 1 pound of commercial formalin to 40 

 gallons of water. 



When the solution is ready, 2 half barrels or vats are 

 so placed as to permit one to drain into the other. The 

 upper vat is then filled a little more than half full of the 

 solution and the grain to be treated is poured into the vat 

 or, what is better, a wire basket, and thoroughly stirred. 

 This will insure the wetting of each kernel and will bring 

 to the surface such smut balls as may not have been blown 

 out by the fanning mill. The immersion period need not 

 be longer than 10 minutes, following which the grain is 



