io 8 
Journal of Agricultural Research 
Vol. XXI, No. a 
of fungous attack, therefore, can be attributed solely to sensitiveness of 
the molds to the chemicals on the seed and are in no way complicated by 
treatment injury to the embryo. The formaldehyde-treated seed gave 
normal germination until destroyed by the molds; and the copper- 
sulphate-treated seed, while averaging only 84 per cent germination after 
treatment, was more resistant to molds than was the less injured, formal¬ 
dehyde-treated seed. 
Table IV .—Relative development of molds on Little Club wheat stored two months under 
varying conditions of temperature and seed treatment 
Seed treatment. 
Storage. 
Relative heavi¬ 
ness of attack 
by molds . 0 
Penicillium. 
Aspergillus. 
Water...... 
Do. 
Refrigerator, io° C.. 
Laboratory, 20° C. . 
Greenhouse, 15° to 
35° C. 
Refrigerator. 
+ + + 
+ + + + 
+ + + 
+ + 
Present. 
.... do .... 
Present. 
Do. 
Do. 
Do. 
Do.. 
.... do 
1 to 320 formalde¬ 
Not present. 
hyde. 
Do. 
Laboratory. 
++++ 
+ 
0 
+++ 
0 
. .. . do . . 
Do. 
Do. 
Not present. 
Present. 
Not present. 
Do. 
Greenhouse. 
do 
1 pound CuS 0 4 to 
4 gallons water. 
Do. 
Refrigerator. 
Laboratory. 
Prf»«;f»nt 
Do. 
Greenhouse. 
Not present. 
° The symbols used indicate that the fungus is present ( + ) or lacking (o), the number of plus signs show¬ 
ing the relative severity of attack. 
From these experiments it appears that seed treatments with copper 
sulphate and formaldehyde are a protection against saprophytic fungi, 
both when the seed is germinated at once and when it is stored damp. 
Formaldehyde is especially effective against Penicillium. 
RELATION OF SEED-COAT INJURY TO INJURY FROM FUNGICIDES 
The fact that all seed injury from the recommended copper-sulphate 
treatments for smut is due to broken seed coats seems to be unknown to 
most agronomists in this country. In only two bulletins ( 12 , 23) 
has the writer found mention of mechanical injury in discussions of the 
injurious effects of copper sulphate, or any attempt to correlate the 
various percentages of injury with the physical condition of the seed 
coat. Yet the principle of semipermeability of wheat and barley seed 
coats is not a new one. Brown (3) reported the discovery that the cover¬ 
ings of the seeds of Hordeum vulgare are seinipermeable membranes, ex¬ 
cluding salts and other substances from the seeds. He reported that 
there was no penetration of'copper sulphate into seeds after soaking 
three days in a 5 per cent solution. In 1909 (4) he published the results 
of further experiments on the impenetrability of seed coats to salts. 
Fischer (9) soaked Sagittana fruits five days in molecular copper sulphate 
without injury. . , 1 
