Treatment of Cotton Seed 
53 
TABLE IV 
Showing the Relation Between Time and Temperature and Loss of Water by Given 
Lots of Seed in Dry Air. 
Exp. No. 
Preliminary 
Desiccation 
Subsequent 
Desiccation 
Weight 
(Water) Lost 
Increase in 
Per Cent of 
Water Lost 
Temp. 
Deg. C. 
Time 
Hours 
Temp. 
Deg. C. 
Time 
Hours 
Grams 
Per Cent of 
Wet Weight 
7* 
45 
24 
0.211 
4 .16 
45 
48 
0.242 
4 .77 
.61 
45 
72 
0.270 
5.33 
.56 
45 
96 
0.275 
5.42 
.09 
45 
120 
0.279 
5.50 
.08 
45 
144 
0.2.80 
5.69 
.19 
45 
144 
60 
24 
0.360 
7.10 
1.41 
45 
144 
60 
48 
0.374 
7.38 
.28 
8 f 
60 
14 
1.133 
9 .91 
60 
23 
1 .185 
10.37 
.46 
60 
40 
1.216 
10.64 
.27 
60 
62 
1.234 
IQ .80 
.16 
60 
86 
1.237 
10.82 
.02 
60 
86 
70 
24 
1.292 
11.31 
.49 
60 
86 
70 
4,8 
1.322 
11.57 
.26 
60 
86 
70 
72 
1.329 
11 .63 
.06 
60 
86 
70 
96 
P.32 
*50 seeds, water content 10.57 per cent of wet weight, heated in gas oven. 
1100 seeds, water content 13.20 per cent of wet weight, heated in electric oven. 
In Experiment 8, in which seeds were heated directly at 60° C., weight 
and water content pf the seeds rapidly decreased during the first 14 hours 
and continued to decrease, although at a diminishing rate, until it became 
constant at the end of 62 hours. When the temperature was raised to 70°, 
a marked decrease of weight again occurred during the succeeding period 
of 24 hours, and the water content again became practically constant by 
the end of 48 hours. 
The results of these experiments are graphically illustrated in Fig. 1. 
The curves show the relation of time to loss of water from seeds which were 
being subjected to two different desiccatory dry heat treatments. Both 
curves rise rapidly at first and then flatten out indicating that longer desic¬ 
cation at that particular temperature does not cause further dehydration. 
Later, the increase in the desiccatory temperature of the treatments is 
marked by an abrupt rise in each curve, and this is followed again by a 
flattening of the curves as desiccation once more approaches its maximum 
for the particular temperatures being used. If the temperature is too low, 
the time of desiccation may be prolonged indefinitely without attaining 
the degree of desiccation requisite to enable cotton seeds to withstand 
without loss of viability the higher temperatures which must be used to free 
it from anthracnose. On the other hand, when an adequate temperature is 
used, a more or less definite minimum of time is necessary in order to 
accomplish a degree of desiccation sufficiently pronounced to protect the 
seeds. 
