i gd ee” le 
INFLUENCE OF GERMICIDES ON GERMINATION. 199 
In 1891, Kellerman Sr., recommended hot water over all other fungicides for great 
efficiency without injury to seeds. His experiments were with wheat kernels for the pre- 
vention of stinking smut. As a result of many experiments (about 70) he recommends 
exposure for 15 minutes to a temperature of 131° F. (55° C.). Hot water for 5 minutes at 
137° F. and at 138° F. (seeds previously soaked 10 hours) destroyed all the grains. The 
following treatments greatly injured or nearly or quite destroyed the grains: Bordeaux, 24 
hours; same, half strength; 1 per cent copper sulphate, 24 hours; 1 per cent copper acetate, 
24 hours; 1 per cent copper chloride, 24 hours; 1 per cent potassium bichromate, 24 hours. 
The following treatments gave reasonably good yields, i.e¢., better than the checks, but not 
as good as the hot water: Copper sulphate 0.5 per cent, 24 hours, limed; copper sulphate 
0.5 per cent, 12 hours, limed; copper acetate 0.5 per cent, 24 hours; copper nitrate 1.0 
per cent, 24 hours; copper nitrate 0.5 per cent, 24 hours; mercuric chloride 0.05 per cent, 
24 hours. The following gave a yield nearly equal to the checks: Eau celeste, 24 hours; 
mercuric chloride, 0.1 per‘cent, 24 hours. Ratio of grain to volume of fluid not given. Hot 
water at 136° F. (57.7° C.) for 5 minutes, then quickly cooled, appears to be the severest 
exposure compatible with a good crop. 
In 1893, Hitchcock and Carleton published the results of their experiments with maize. 
They tested the effect on germination of 82 chemicals in various strengths, making a total 
of 400 experiments. 
They obtained in moist sand a germination of 80 to 100 per cent (retarded) after 
exposure to the following strengths of mercuric chloride water: 0.1 per cent for 1, 3, 5, 8, 
hours; 1.0 per cent for 1 hour. One per cent mercuric chloride for 24 hours or 3 per cent 
for 1 hour killed all. Chromic acid 1 per cent for 48 hours gave 75 per cent retarded germi- 
nations. Copper chloride 1o per cent for 24 hours gave roo per cent retarded germinations. 
Copper nitrate 10 per cent for 24 hours gave about 80 per cent retarded germinations. 
Potassium permanganate 2.5 per cent for 24 hours gave 100 per cent germinations. Hy- 
posulphite of soda 10 per cent for 24 hours gave full germinations. From 80 to 100 per cent 
of retarded germinations were obtained after exposure to potassium cyanide as follows: 
I per cent, 1 hour; 5 per cent, 1 and 3 hours; 10 per cent, 1 hour. The same, 0.5 per cent 
for 1 hour scarcely affected germination. 
In 1897, Bolley published studies on the fungicidal treatment of wheat, oats and 
barley which he had carried on for a period of 5 years. The following are some of his con- 
clusions respecting resistance of the dry grain. He states that if the wheat grain is dried 
at once germination is not retarded by applying corrosive sublimate solutions in strengths 
up to 4 parts in 1,000 parts of water: Of selected seed-of Scotch Fife wheat exposed 2 
minutes, 95 per cent germinated; exposed 3 minutes, 82 per cent germinated; 4 minutes, 
72 per cent; 5 minutes, 78 per cent; 6 minutes, 67 per cent; 7 minutes, 45 per cent; 20 
minutes, 17 per cent; 25 minutes, o. As little as 0.1 per cent corrosive sublimate weakened 
the first growth in a rapidly increasing degree in exposures longer than 3 minutes, but even 
from too strong treatments the final after-growth is stronger than from untreated grain. 
Mixed samples of oats treated with 0.3 per cent corrosive sublimate water for 30 minutes 
gave good first growth (94 to 100 per cent germinations) and a good yield per acre. Barley 
after 15 minutes exposure to 0.3 per cent mercuric chloride gave 94 per cent germinations. 
Seed wheat treated 10 minutes or less with 1 to 2 per cent solution of formalin gave a 
normal number of germinations or better, but soaking over 10 minutes decreased slightly 
the per cent of germinating seeds. Exposure for 10 minutes to ro per cent killed all, and 
merely dipping into 5 per cent reduced the germinations to 34 per cent. Subsequent experi- 
ments showed that wheat or oats would germinate perfectly after soaking in 0.4 per cent 
formalin 1 to 3 hours. 
Seed wheat will stand an exposure of 1 minute at 150° F. (65.5° C.) and give 80 to 90 
per cent of germinations. Oats exposed to hot water at 140° to 143° F. for 5 minutes gave 
