96 
Journal of Agricultural Research 
Vol. XXVIII, No. 1 
(4) The modified hot-water treatment reduced the germination of wheat seed 
to zero or nearly zero when the seed coats were broken over the embryo. Seed 
not killed germinated abnormally. 
(5) Reduction and abnormality in germination also occurred when seed coats 
were broken over the endosperm, but somewhat less severely. The degree of 
severity depended upon the location of the fracture. 
(6) Seed with unbroken coats suffered a retardation in germination following 
treatment but there was little if any reduction in germination. 
(7) Removal of the pericarp did not diminish the protective ability of an 
otherwise unbroken seed coat. 
(8) Unbroken seed coats exerted their protective action during both the pre¬ 
soak and 10-minute baths of the modified hot-water treatment; the major por¬ 
tion during the 10-minute treatment. 
(9) Increase in the duration of presoaking increased the amount of injury 
from the 10-minute treatment rapidly when the seed coats were broken, and 
relatively very slowly when the seed coats were unbroken. 
(10) In the absence of any presoak period, the 10-minute treatment caused 
severe injury when seed coats were broken over the embryo. 
(11) The rate of water absorption by the seed was more rapid when the seed 
coats were broken. 
(12) Injury to seed coats is caused mainly in the process of threshing. All 
machine-threshed seed examined showed broken seed coats. 
(13) Widely different weather conditions during the period between ripening 
and harvesting of seed had a marked effect on the amount of injury sustained by 
seed coats in the process of threshing and consequently in the amount of injury 
sustained by the seed from treatment. 
(14) Small, shriveled kernels survived treatment as well or better than large, 
plump kernels from the same lot of machine-threshed seed. 
(15) Injury and killing caused by treatment when the seed coats are broken 
may be due to coagulation of leucosin in the wheat embryo. 
(16) Plants grown from treated seeds spaced in the rows were fewer in number 
and produced slightly fewer culms per plant than spaced plants from untreated 
seeds. 
(17) Under less favorable soil conditions, the reduction in yield from treated 
seed was over four times the reduction in yield from untreated seed. 
(18) The bushel weight of wheat grown from treated seed was not appreciably 
greater than that grown from untreated seed. 
(19) Yield experiments were conducted for three years and a total of nine 
different lots was employed. In each of the three years wheat grown from 
untreated seed outyielded that grown from treated seed when the rate of seed¬ 
ing was 6 pecks per acre. In the third year, treated seed yielded better than 
untreated smutted seed when the former was sown dry and when the seeding 
rate was adjusted to compensate for wheat killed in treatment, as determined by 
a germination test in soil. 
