Treatment of Cotton Seed 
20 
TABLE XIII 
Per Cent of Anthracnose and Germination in Cotton Seed Which Has Been 
Subjected to Drying at 50 to 60° C. and Subsequent Heating at 95° C.* 
Exp. 
No. 
Lot 
No. 
Preliminary 
Drying 
Subsequent 
Heating 
Per Cent 
Anthracnose 
Temp. 
Deg. C. 
Time 
Hours 
Temp. 
Deg C.. 
Time 
Hours 
Treated 
Untreated 
1 
1 
50 
24 
95 
13 
0 
2 
1 
50 
18 
95 
24 
0 
2 
50 
24 
95 
24 
0 
3 
1 
50 
18 
95 
12 
ot 
82 
4 
1 
50 
24 
95 
12 
0 
42 
2 
50 
24 
95 
12 
0 
5 
1 
50 
24 
95 
7 
0 
2 
50 
24 
95 
10 
0 
3 
50 
24 
95 
5 
0 
4 
50 
24 
95 
12 
0 
6 
1 
50 
12 
95 
8 
0 
2 
50 
18 
95 
8 
0 
3 
50 
24 
95 
8 
4 
4 
50 
36 
95 
9H 
•0 
7 
1 
60 
24 
95 
10 H 
Of 
2 
60 
24 
95 
12 
Ot 
8 
1 
60 
24 
95 
ll Vi 
Of 
26 
2 
60 
24 
95 
8 
It 
9 
1 
60 
6 
95 
12 
0 
2 
60 
12 
95 
12 
0 
3 
60 
18 
95 
12 
0 
4 
60 
24 
95 
12 
0 
Per Cent 
Germination 
Treated 
Untreated 
90 
64 
72 
84 
56 
84 
56 
84 
74 
46 
38 
68 
80 
96 
95 
98 
95 
97 
20 
86 
94 
96 
98 
98 
100 
96 
*Seed of 1922 crop was used in Exp. 1 and 2; 1923 crop in Exp. 3-9. At the time of making the treat¬ 
ment the seed used in Exp. 1 and 2 was 12 and 13 months old, that in Exp. 3-9 varied in age from - 
to 6 months. 
fl00 seeds. 50 seeds in all lots not so marked. 
As shown by table XIII anthracnose developed on seedlings from only 
two lots of treated seed, and in these two instances, namely Exp. 6, lot 
3, and Exp. 8, lot 2, the seed had been heated for only 8 hours. In all 
the remaining lots of treated seed, some of which were heated for less 
than 8 hours, the viatality of the anthracnose fungus was completely de¬ 
stroyed while the untreated check lots yielded a high percentage of diseased 
seedlings. 
The germination of the seed treated in Experiments 1-6 lot 3 was in most 
cases seriously reduced in comparison with that of the checks. Obviously, 
the heating of cotton seed containing a normal amount of moisture at 
50° for 24 hours or less does not prepare the seed to withstand temperatures 
of 95° C. for any considerable period without marked loss of viability. 
When the seed are heated at 50° for 36 hours (Exp. 6, lot 4) or at 60° for 
18 and 24 hours (Sxp. 7, 8, and 9, lots 3 and 4), excellent germination 
followed the subsequent treatment at 95° for 8 to 12 hours. 
EXPERIMENTS WITH SEED IN BULK 
As soon as it began to appear from the results of the tests made with 
seed in lots of 50 or 100 that control of anthracnose might be obtained by 
the application of dry heat for appropriate periods of time, experiments 
testing the efficiency of this method in the treatment of larger quantities 
of seed were begun. Use was made in a number of these tests of small gas and 
electric ovens such as are ordinarily found in plant pathological laboratories. 
In some of the tests the seed were spread out on the oven shelf; in others, 
