26 
N. C. Experiment Station 
table x 
Per Cent of Anthracnose and Germination in Cotton Seed Subjected to 
Preliminary Drying at 40 to 50° C. and Subsequent Heating at 80° C.* 
Exp. 
No. 
Lot 
No. 
Temp, of 
Prelim. 
Drving 
Deg. C. 
Time of 
Prelim. 
Drying 
Hours 
Temp, of 
Heating 
Deg. C. 
Time of 
Heating 
Hours 
Per Cent of Seeds 
Developing Dis¬ 
eased Seedlings 
Per Cent of Seeds 
Germinated 
Treated 
Untreated 
Treated 
Untreated 
1 
1 
50 
24 
80 
24 
10 
96 
2 
50 
24 
80 
48 
12 
94 
2 
1 
40-45 
48 
80 
48 
22 
98 
2 
40-45 
48 
80 
72 
0 
94 
3 
1 
40-45 
24 
80 
72 
0 
34 
80 
98 
4 
1 
40-45 
48 
80 
72 
0 
46 
86 
98 
5 
1 
40-45 
24 
80 
48 
2 
54 
88 
90 
2 
40-45 
24 
80 
72 
0 
54 
88 
90 
6 
1 
40-45 
24 
80 
48 
4 
64 
94 
94 
2 
40-45 
24 
80 
72 
0 
64 
92 
94 
7 
1 
40-45 
72 
80 
24 
30 
64 
94 
94 
2 
40-45 
72 
80 
48 
2 
64 
96 
94 
8 
1 
40-45 
48 
80 
48 
2 
96 
9 
1 
50 
12 
80 
72 
2 
98 
* In rl5 xp ' 1_4, s „ ee ^ of the 1920 cr °p vvas used; in Exp. 5-8, seed of 1921 crop; in Exp. 9, seed of 1923 
crop. 1 he age of the seed used ranged from 3 to 10J4 months. 
At the temperature of 80° C. the seed-borne infection is seen to be greatly 
reduced by the end of 48 hours and completely devitalized in every test 
except one by the end of 72 hours. The 12-hour period of preliminary desicca- 
tion at 50° C. and the 24-hour period at 40-45° and 50° are as effective as 
the 48-hour period in preparing the seed to resist the high temperature 
of the different periods of heating. Prolonging the period of drying to 72 
hours does not make it possible to shorten the period of heating to 48 hours. 
In order to render this method of seed treatment more economical of 
time and heat, it seemed advisable to determine whether the effective period 
of heating at 80° C. namely, 72 hours, could be shortened by the use of a 
higher temperature. Accordingly, a number of tests were made in which 
infected seed were subjected to a treatment consisting of a preliminary 
desiccation of 40-45° C. or 50-53° C. immediately followed by a period of 
heating at 90° C. The results of these tests are presented in Table XI. 
