88 
Journal of Agricultural Research 
Vol. XXVIII, No. I 
the relationship between water content of the seed and injury by treatment in the 
presence of broken and unbroken seed coats, several experiments were conducted. 
In the first, 8 lots each containing 100 hand-threshed kernels of the variety Haynes 
Bluestem (C. I. 2874) were used. In 5 of the lots the seed Coats were broken over 
the embryo with a needle. Some of the lots were presoaked for varying periods, 
as shown in Table IX, and a record was made of the resultant increases in weight. 
The seed coats were undisturbed in three of the lots. All of the seed was sub¬ 
jected simultaneously to the 10-minute treatment at 54° C., on February 15, 1923, 
then dried five days at room temperature, and sown in flats in the greenhouse 
on February 20. The seedlings were counted on March 20 and the results are 
presented in Table IX and in Plate 5. 
Table IX.— Percentages of germination and increase in weight of hand-threshed 
seed of Haynes Bluestem wheat ( C . I. 287If) with broken or unbroken seed coats t 
some presoaked during different periods prior to treatment with hot water 
Lot No. 
Condition of seed coat 
Length of 
presoak 
bath 
Weight 
of seed 
before 
presoak 
bath 
Weight 
of seed 
after 
presoak 
bath 
Increase 
in 
weight 
10-minute 
treatment 
at 54° C 
Germina¬ 
tion 
1. - . 
Broken over the embryo 
...do. 
Hours 
0 
Gm. 
Gm. 
Per cent 
Untreated. 
Per cent 
96.0 
2 
! 0 
Treated. 
38.0 
3 
_do. 
1 
3.260 
3.745 
14.9 
.do. 
19.0 
4. 
.do. 
2 
3.180 
3.860 
21.4 
.do. 
15.0 
ft ... 
.. .do. 
! 4 
3.250 
4.130 
27.1 
.do. 
4.0 
6. 
Unbroken. 
0 
Untreated. 
95.0 
7. 
_do. 
! 8.5 
3.370 
4.510 
33.8 
Treated. 
96.0 
8. 
.. .do. 
j 10.5 
3.380 
4.660 
37.9 
.do. 
93.0 
Table IX shows (1) that in the absence of the presoak bath severe reduction 
in germination resulted from the 10-minute treatment when the seed coats were 
broken over the embryo (lot 2); (2) that injury increased with increase in dur¬ 
ation of presoak and moisture content when the seed coats were broken over the 
embryo (lots 3, 4, and 5); and (3) that treatment did not impair germination 
appreciably when the seed coats were unbroken despite a high increase in water 
content (lots 7 and 8), (PI. 5). 
The relationship between increase in the duration of the presoak period and 
injury to seed with unbroken coats was studied further in the experiment which 
follows. Three lots each containing 50 hand-threshed seeds were prepared from 
each of four varieties of wheat. The three lots from each variety were pre¬ 
soaked 5, 10, and 15 hours, respectively, on February 18, 1923, then all were 
treated simultaneously in the 10-minute bath at 54° C., dried at room tempera¬ 
ture for one week, and sown on February 25 in soil in greenhouse flats. The 
germination counts were made aftef 10, 15, and 30 days. The results are pre¬ 
sented in Table X. 
