INJURY TO SEED WHEAT RESULTING FROM DRYING 

 AFTER DISINFECTION WITH FORMALDEHYDE 



By Annie May Hurd j 



Assistant Pathologist, Office of Cereal Investigations, Bureau of Plant Industry, United 

 States Department of Agriculture 



INTRODUCTION 



Much has been written on the use of formaldehyde as a fungicide 

 for wheat and other grains infested with smut, but relatively little has 

 been carefully done on the effect of such treatment on the seed. The 

 usual recommendation has been a dip of about 10 minutes in a solu- 

 tion consisting of i part of commercial formaldehyde solution to 320 

 parts of water, followed by a 10-minute drain. Almost without excep- 

 tion instructions are given to dry the seed thoroughly before storing 

 it. The frequent advice that it be sown immediately after treatment 

 and not stored indicates that it has been learned by experience that 

 injury to the grain occurs not so much from the treatment as from 

 holding it in storage afterward. However, it has been almost univer- 

 sally concluded, without experimental evidence, that damp storage 

 causes the injury. Thus, practically every publication dealing with 

 seed treatment carefully warns against the storage of formaldehyde- 

 treated seed that has not been thoroughly dried after treatment. 



The present investigation of the post-treatment action of formalde- 

 hyde on seeds was begun in 191 8 in the plant pathology laboratories 

 of the University of California as a part of the cereal-smut eradication 

 campaign carried on by the United States Department of Agriculture 

 and was continued through a period of nine months. The major con- 

 clusion reached is that it is extremely hazardous to dry seed which 

 has been treated with formaldehyde solution, 2 and that, contrary to 

 common belief, seed wheat is absolutely uninjured by a 0.1 per cent 

 solution (1 to 40) and, if kept moist, may be held indefinitely without 

 injury, unless attacked by molds. We believe that the data here pre- 

 sented will contribute to our knowledge of the physical and chemical 

 properties of formaldehyde and the relation of these properties to 

 physiological processes in the seed. Such knowledge will undoubtedly 



1 The writer wishes to acknowledge with gratitude the helpful suggestions of Dr. C W. Porter and 

 Dr. G. R. Gray, of the University of California, and the hearty cooperation of Prof. W. W. Mackie during 

 this study of formaldehyde. To Dr. H. B. Humphrey she is indebted for assistance in the preparation 

 of this report, and to Mr. A. A. Potter for cooperation in the preparation of the bibliography. 



3 Reports sent in to Dr. H. B. Humphrey and to Prof. W. W. Mackie of occasional poor stands of wheat 

 from treated seed sown by farmers in the dry regions of California and Oregon indicate that field results 

 confirm those arrived at through these experiments. 



Journal of Agricultural Research, Vol. XX, No. j 



Washington, D. C Nov. i, 1920 



vj Key No. G-206. 



(209) 

 9507°— 20 4 



