88 
Colorado Experiment Station 
40% formaldehyde diluted to 40 gallons is the usual formula al- 
though in special cases different proportions are used. The length 
of the treatment varies with the seed treated. Use as directed for 
the particular disease and crop. 
There are three standard methods of treating grain with for- 
maldehyde. Twenty years of use have shown these to be efficient 
and reliable. These are: (1) The soaking method, (2) The open 
tank method, and (3) The sprinkling method. Directions for the 
use of each of these methods are given below. Select the method best 
adapted to your conditions and equipment and then follow the 
directions carefully. 
THE SOAKING METHOD 
1. Estimate the amount of seed to be treated and purchase for- 
maldehyde (40 per cent strength) one pint for 40 bushels of grain. 
2. Clean the seed thoroughly by fanning so as to remove all un- 
broken smut balls. 
3. Dilute the formaldehyde at the rate of one pint to 40 gallons 
of water. 
4. Put a sufficient amount of the diluted solution into a barrel 
or tank to immerse one or more sacks of seed. 
5. Put seed in gunny sacks and immerse in solution. Do not fill 
the sacks too full; allow room for agitation of the grain so that 
each seed will become thoroughly wet. 
6. Leave the seed in the solution length of time specified in 
Table I. 
7. Remove the sacks and drain, allowing the excess solution to 
run back into the barrel or tank. Replenish the solution when it 
gets too low. 
8. Leave the treated grain in the wet sacks for not less than six 
hours nor more than 12 hours. Place the sacks where they will drain 
rapidly. 
9. Plant immediately or empty the grain and spread out in a 
thin layer to dry. Drying may be facilitated by frequent shoveling. 
THE OPEN TANK METHOD 
1. Make the formaldehyde solution the same as for the soaking 
method. 
2. Pour the loose grain slowly into the solution in an open vessel. 
Stir thoroughly and skim off the smut balls. 
3. Soak for length of time specified in Table I. 
4. Remove the grain, pile, and cover with wet sacks or canvas for 
not less than six hours and no more than 12 hours. 
