Nov. i, 1920 Effect of Drying Disinfected Seed Wheat 2 1 1 



attributed the conflicting reports of the injury resulting from the for- 

 maldehyde treatment to variations in the deposit of this polymer on the 

 seed as it dried. They found low germination percentages and defective 

 seedlings to result from the drying of treated seed. Their results do not 

 agree with those of McAlpine, which were responsible for the latter's 

 conclusion that soaking in water prior to sowing removed the cause of 

 injury. They did find, however, that washing immediately after treat- 

 ment prevented subsequent injury in storage by removing the source of 

 the deposit. They thought that there was no internal poisoning of the 

 seed before germinating but that there was some deleterious chemical 

 action of a formaldehyde salt in the pericarp, which was alleviated by 

 soaking. Miiller and Moltz (12) proved that the polymer, paraformalde- 

 hyde, when mixed with the soil was very injurious to wheat sown in it. 



An interesting and comprehensive report on the secondary effects of 

 formaldehyde treatment is the recent article by Kiessling (9). He ob- 

 tained severe injury upon storing treated seed which had been dried, and 

 this injury he found to be cumulative as the duration of the storage period 

 continued. He also was unable to confirm McAlpine's statement that 

 soaking the dried seed before sowing prevented the injury. Although 

 giving adequate and convincing proof that dry storage is more fatal than 

 damp storage, he does not advance any explanation. 



Coons (4) also found that it is unwise to hold formaldehyde-treated 

 grains any length of time and that the injurious action is cumulative 

 when the treating solution is dried on the seed. He suggests that this 

 injury may be due to the formation of the solid condensation product, 

 paraformaldehyde, which might persist on the grain even after months of 

 drying. 



POST-TREATMENT ACTION OF FORMALDEHYDE ON DRYING SEED 



WHEAT 



Except the studies of Coons (4) and those of Stewart and Stephens (16), 

 it will be noted that all the work on dry-storage injury to wheat has been 

 done outside the United States. This no doubt accounts for the fact 

 that it has been generally overlooked in this country or at least has not 

 resulted in any modification of the widespread instructions relative to 

 drying formaldehyde-treated wheat before storage. It was to investi- 

 gate this supposed formaldehyde injury to damp stored seed that the 

 studies here recorded were begun. These experiments resulted in the 

 rediscovery of the fact that so long as the seed treated with a 0.1 per 

 cent (1 to 40) solution remains damp there is no injury from the chemical 

 but, when dried, the seed is variously injured, depending upon the man- 

 ner of drying and upon the moisture content of the atmosphere surround- 

 ing the seeds. 



