28 
N . C. Experiment Station 
TABLE XII 
Per Cent of Anthracnose and Germination in Cotton Seed Which Has Been Subjected 
to Preliminary Drying at 40-63° C. and Subsequent Heating at 100° C.* 
Exp. 
No. 
Lot 
No. 
Preliminary 
Drying 
Final 
Heating 
Per Cent of 
Anthracnose 
Per Cent 
Germination 
Temp. 
Deg. C. 
Time 
Hours 
Temp. 
Deg C. 
Time 
Hours 
Treated 
Untreated 
Treated 
Untreated 
1 
1 
40-45 
24 
100 
11 
0 
22 
2 
40-45 
94 
100 
24 
0 
50 
2 
1 
50 
24 
100 
2 
6 
32 
2 
50 
24 
100 
414 
0 
6 
3 
1 
50 
24 
100 
6 
40 
4 
1 
50 
24 
100 
12 
0 
38 
68 
92 
2 
50 
24 
100 
6 
0 
58 
5 
1 
60 
24 
100 
6 
0 
20 
84 
92 
*Seed of the 1921 crop was used in Exp. 1-3;* 1922 crop in Exp. 4; 1923 crop in Exp. 5. 
A study of the data presented in this table shows that anthracnose devel¬ 
oped on the seedlings in only one test, and in this instance, the seed had 
been heated only 2 hours. Inasmuch as germination was greatly reduced 
in all the tests after heating the seeds at 100° C., attempts to control 
anthracnose by use of this temperature were for a time discontinued. 
Several months later, after the encouraging results reported below had 
been obtained in the experiments in which temperatures at 60 and 95° 
were employed, another test was made in which 15 month old seed of the 
1923 crop were heated at 100° for 6 hours. These seeds had been previously 
dried at 60° for 24 hours. Upon germination, none of the seedlings from 
treated seeds developed anthracnose (Table XIII, Exp. 5) while 20 per cent 
of those from untreated check seeds became diseased. Germination was 
appreciably but not excessively reduced by the treatment, 84 per cent of 
the heated seeds surviving the treatment. 
The data embodied in Table XIII were obtained in a large number of 
tests in an effort to get better control of anthracnose than was obtained 
by heating seeds at 90° C. and still to obtain higher germination than 
seemed possible by the use of 100° C. In tests 1 to 6 the seeds were dried 
at 50° C. for periods of 12 to 36 hours, and in tests 7 to 9 the preliminary 
drying was done at 60° C. for 12 to 24 hours. The different lots were then 
heated at 95° C. for periods varying from 5 to 24 hours. In tests 8 and 9 
the oven was provided with a recording instrument which made a con¬ 
tinuous record of the temperature of the oven for the entire period of the 
treatment. The records of this instrument show that while the several 
lots of seed of these two experiments were being treated, no serious fluctua¬ 
tion of temperature occurred. 
