THE VIABILITY OF RADISH SEEDS 
'Three series of similar samples of radish seeds containing an initial 
water content of 19 percent were heated at temperatures from 45° C. 
to 105° C. for a period of thirty minutes (Table V). The samples 
of Series i were heated directly in water, those of Series 2 in 100 c.c. 
flasks immersed in water, and those of Series 3 in an oven. The seeds 
were placed upon the plaster blocks for germination. The results in 
percent of germination are recorded in Table V. 
Table V 
The Effect of Different Methods of Heating upon the Germination of Seeds 
Temperatures Employed 
45° 
50° 
55° 
60° 
65° 
70° 
75° 
80° , 85O 
90° 
95° 
100° 
105O 
Percent of germination of seeds 
When heated in water. Se- 
ries I 
88% 
80 
58 
2 
0 
0 
When heated in flasks. Se- 
ries 2 
89 
87 
81 
66 
18 
9 
0 
0 
When heated in oven. Se- 
ries 3 
89 
88 
84 
76 
60 
6 
0 
Checks, untreated 
88% 
90 
89 
88 
89 
91 
,90 i 90 
89 
88 
90 
90 
89 
The results as given in this table show very clearly that radish 
seeds of similar water content when heated as indicated in Series 1,2, 
and 3, respectively, exhibit very difTerent degrees of resistance. The 
samples heated directly in water suffered a loss at 50° C. and were 
killed at 65° C; those heated in flasks suffered a similar loss (approxi- 
mately 8 percent) at 60° C. and were killed at 80° C; those heated in 
the oven suffered a loss of 85° C. (5 percent) and were killed at 105° C. 
Further it is to be noted that in Series i the effects of the temperature 
are distinctly manifested at 50° C. and that from this temperature 
the viability decreases very rapidly, extending through a range of 
only 15° C. In Series 2 similar effects are noted 10° C. higher, namely 
60° C, and the viability decreases less rapidly, namely extending 
through a range of 20° C. The most marked effect is shown in Series 
3. The effects of the treatment here lie 35° C. higher than in Series 
I and 25° C. higher than in Series 2. The decrease in viability is 
slow at first and then very rapid, falling from 60 percent germination 
at 95° C. to 6 per cent at 100° C. 
The data recorded in Table V, Series 2, are practically a repetition 
of those found in Tables I, II, and III, for an approximately similar 
initial water content. Starting with an initial water content of 19 
percent in Series i. Table V, we find the injury essentially equivalent 
