MiIvLKT Smuts and Their Control 
19 
this reason, the best method of control lies in a good, thoro dis¬ 
infection of the seed whereby the smut spores are killed, but the vi¬ 
tality of the milletiis uninjured. 
TABLE III.—EFFECTS OF FORMALIN UPON SPORE GERMINATION 
Cultures Treatment Percentage of Spor® 
Germinations 
1 . 
Formalin 
1 
pint 
to 
40 gals, water 
0 
2. 
99 
50 ” 
0 
3. 
99 
99 
60 
0 
4. 
99 
99 
80 
0 
B. 
9 9 
99 
100 
Slight 
6. 
99 
99 
120 
0.1 
7. 
99 
99 
140 
Free germination 
Ustilago crameri Plot 11, Row 2—1917 
The seed treatment recommended herein is very simple, readily 
performed, effective, and quite inexpensive. Considering these facts, 
in judging the advisability of treating smutted grain, there should 
be but one conclusion—treat all affected seed yourself and thereby in¬ 
sure the crop against unnecessary losses from smut. 
In organizing experiments on the control of millet smut, it seem¬ 
ed advisable to experiment exclusively with formalin since it is now 
adopted as a standard method of control for all the cereal smuts where 
seed treatment is needed. Formalin is a commercial name applied 
to a 40 percent solution of formaldehyde, which is a gas. While not 
poisonous, it has a very pungent odor, and is one of the most effective 
disinfectants and fungicides now in use. In order to determine the 
best proportion of formalin and water to be used, it was necessary to 
expose both millet and smut spores to the disinfectant in various 
strengths for varying lengths of time. 
TABLE IV.—EFFECT OF FORMALIN UPON VIABILITY OP MILLET SEED 
The seed was soaked in the solutions listed below from 40-60 minutes and 
then dried 
‘ Germination after 4 days 
Lot 
Treatment 
Com¬ 
Ger- 
Siber¬ 
Aver¬ 
mon 
’ man 
ian 
age 
1. 
Formalin 
1 pint 
to 
20 
gals, water 
75 
73 
75 
74.3 
2. 
>9 
99 99 
99 
25 
99 99 
78 
80 
77.5 
78.5 
3. 
99 
99 99 
99 
30 
99 99 
83 
86 
78.5 
82.5 
4. 
99 
99 99 
99 
35 
99 99 
84 
91 
85.5 
86.8 
5. 
99 
99 9 9 
99 
40 
99 99 
86 
82 
86 
84.6 
6. 
99 
9 t 99 
99 
45 
99 99 
87 
86 
87 
86.6 
7. 
99 
99 99 
. 9 
60 
99 99 
89 
92 
83 
88 
8. 
Creek untreated 
91 
94 
89 
91 
Some have recommended a treatment of the grain in this solu¬ 
tion for two hours but in these experiments a shorter time was tried 
