MICIIICAN ACAIULMV (>K SCrilNCi;. US.) 



method, the ease of apiilioation and the rapidity with which tlie adequate 

 amount of formaldehyde is applied tempted farmers to over-dose. Applica- 

 tions five times the advised strength were common and invariably did damage 

 to germination. It was a common practice to over-dose and to leave covered 

 over night. The long period of covering as compared with tlie recommended 

 4 hours led to severe injury to germination under the weather conditions 

 then prevailing. Many farmers left treatetl grain sacked, not recognizing that 

 sacking was essentially covering. Injuries of this type which arose imder 

 conditions where directions wei*e carefully followed were investigated and 

 many interesting facts discovei'ed. It was shown that with series of successive 

 plantings, the first sown wheat would show perfect stand, while that which 

 was planted after two or three days in sacks or in thin piles was weak, if not 

 worthless. Wheat injured by formaldehyde produced curled, distorted, yellow, 

 spindling sprouts, which often failed to emerge from the ground. Airing of 

 grain did not remove the formaldehyde. Injury accompanied both wet and 

 dry handlings of grain. 



A series of laboratory tests tising small quantities of wheat (pint or 

 quart) and carefully measured amounts of formaldehyde in proportion such 

 as were used in commercial treatments, were carried out. In general, the for- 

 maldehyde was applied by means of an atomizer whose capacity per "whiff" 

 was calculated. The grain was exposed to the action of the formaldehyde in 

 low glass vessels. The treated grain was covered the proper length of time 

 and was then planted in the soil, — germination tests on blottei's being found 

 to give results not comparable with field studies. 



The following conclusions were drawn from the tests : 



Formaldehyde injury to wheat can readily be produced in the laboratory 

 by increasing the amount of chemical or time of exposure. In this regard, 

 wheat is more sensitive than either oats, barley or rye. 



The standard wet treatment (1 pint to 40 gallons of water) or the new 

 dry treatment each reduce germination slighly, but not more than 10%. 



Formaldehyde does not air readily out of grain, but instead seems to per- 

 sist, probably in a paraformaldehyde form, for a long time. Tests were 

 obtained with a sensitive indicator on treated grain which had been exiwsed 

 in the warm air of a laboratory for many months. 



The action of this relict formaldehyde is cumulative, since the damage 

 to germination may be from 50% to total. 



The toxic action serves either to kill the embryo or to cause grave distor- 

 tion. In this, sense of direction of growth is lost and the shoots turn and 

 twist without emerging from the soil. Under cold, wet conditions very little 

 of the formaldehyde will air from grain, due to the low vapor tension of the 

 formaldehyde. 



