Treatment of Cotton Seed 
27 
TABLE XI 
Per Cent of Anthracnose and Germination in Cotton Seed Which Has Been 
Subjected to Preliminary Drying at 40 to 60° C. and Subsequent 
Heating at 90° C.* 
Exp. 
No. 
Lot 
No. 
Preliminary 
Drying 
Heating 
Per Cent of Seeds 
Developed Dis¬ 
eased Seedlings 
Per Cent 
Germination 
Temp. 
Deg. C. 
Time 
Hours 
Temp. 
Deg. C. 
Time 
Hours 
Treated 
Untreated 
Treated 
Untreated 
1 
1 
40-45 
48 
90 
48 
0 
34 
56 
98 
2 
40-45 
48 
90 
72 
0 
22 
2 
1 
40-45 
24 
90 
24 
0 
54 
2 
40-45 
24 
90 
48 
0 
70 
3 
1 
40-45 
24 
90 
6 
30 
88 
2 
40-45 
24 
90 
13J^ 
0 
80 
4 
1 
50-53 
24 
90 
10 
14 
100 
2 • 
50-53 
24 
90 
14 
2 
94 
5 
1 
50-53 
24 
90 
18 
0 
82 
2 
50-53 
24 
90 
24 
0 
78 
6 
1 
50 
24 
Not 
Not 
90 
88 
94 
90 
heated 
heated 
2 
50 
24 
90 
18 
4 
88 
94 
90 
7 
1 
50 
24 
90 
18 
Of 
93 
8 
1 
50 
24 
90 
24 
0 
96 
9 
1 
40 
24 
90 
18 
0 
m 
36 
92 
2 
45 
24 
90 
18 
2 
16 
62 
92 
3 
50 
24 
90 
18 
0 
16 
96 
92 
4 
55 
24 
90 
18 
0 
16 
96 
92 
5 
60 
24 
90 
18 
0 
16 
98 
92 
10 
1 
50 
18 
90 
24 
0 
42 
68 
96 
2 
50 
18 
90 
24 
0 
88 
11 
1 
50 
18 
90 
20 
It 
82 
97 
100 
12 
1 
50 
12 
90 
24 
2 
62 
2 
50 
18 
90 
24 
0 
92 
3 
50 
24 
90 
24 
0 
96 
4 
50 
36 
90 
24 
0 
96 
*Seed of 1920 crop was used in Exp. 1; 1921 crop in Exp. 2-5; 1922 crop in Exp. 6-9; 1923 crop in 
Exp. 11-12. The age of the seed varied from 1 to 12 months. 
1100 seeds in this lot; 50 seeds in all others not so marked. 
JThe seed used had been delinted for 30 min. in H 2 SO 4 . 
A study of Table XI shows that the anthracnose fungus was killed in 
six and greatly reduced in amount in the remaining two of the eight tests 
in which the seed were heated at 90° C. for 18 hours. The disease was 
completely eliminated in eight of the nine tests in which seed were heated 
for 24 hours and failed to develop in any test when the seed had been treated 
for as long as 48 hours. A relatively large proportion of the infective 
material survived the 6 and 10-hour periods. 
The low percentages of germination in Experiments 1, 2, and 9 (Table 
XI) show that a preliminary drying at 40-45° C. for 24 and 48 hours 
does not well prepare cotton seeds to endure a temperature of 90° C. for 
any considerable length of time. When they had been given a preliminary 
treatment at 50° for 24 hours (Exp. 5, 8, 9, and 12), little or no reduction in 
germination occurred as a result of heating at 90°. 
In an effort to further reduce the time required for this treatment, a 
number of tests were made using 100° C. as the major temperature. Seeds 
harvested in 1921 and 1922 were dried for 24 hours at 40-45° C., or at 50° C. 
then heated at 100° for periods varying from 2 to 24 hours. The results of 
these tests are embodied in Table XII. 
