Apr. 5, 1924 
Effect of Modified Hot- Water Treatment on Wheat 
95 
Table XVIII.— Bushel weight of wheat grown from five lots of untreated and of 
treated seed used in the yield experiments of 1922 (see Table XIV) 
Variety 
C.I. 
No. 
Red Chaff. 
.do. 
.do. 
Fulcaster. 
6162 
1915 
Purplestraw. 
Lot 
No. 
Average. 
Bushel weight in pounds of wheat grown from- 
Untreated 
seed sown in plats 
Treated seed sown in plats 
1 
2 
3 
4 
5 
1 
2 
3 
4 
5 
55.25 
55.00 
54.75 
55.00 
55.00 
56.25 
56.50 
54.25 
54.50 
54.50 
54.00 
56.00 
52.75 
53.00 
53.50 
54.75 
57.00 
53.50 
53.75 
53.50 
56.00 
56.00 
55.00 
55.75 
53.75 
55.50 
55.00 
54.75 
55.50 
53.25 
51.50 
51.75 
51.00 
51.50 
50.50 
51.25 
51.50 
52.00 
52.50 
50.50 
55.00 
54.50 
56.25 
56.50 
55.75 
55.00 
55.00 
55.75 
56.00 
55.75 
54.20 
54.31 
Table XVIII shows a difference in weight of grain in favor of wheat from 
treated seed but it amounts to less than ? ounces per bushel. 
DISCUSSION 
The effects of the modified hot-water treatment on wheat, so far as deter¬ 
mined, have been shown to be largely dependent on the conditions of seed coats 
and soil. The latter varies greatly and the physical condition of the seed coats 
is dependent on the combination of such variable factors as the kind of weather 
during the period from ripening to threshing of grain, adjustment and speed of 
cylinder in the threshing machine, size of the wheat kernel, and handling of 
grain after threshing. It is evident, therefore, that the action of treatment 
varies and can not be predicted. The effects of treatment on the germination 
of machine-threshed seed were severe. The average soil germination of 58 differ¬ 
ent lots of machine-threshed seed (Tables III and VII) representing 32 distinct 
varieties was 33.3 per cent less for the treated than for the untreated wheat. 
In none of the lots did the germination of the treated seed equal that of the 
untreated. Even when the seed coats were intact, the modified treatment 
measurably retarded germination although it reduced germination very little, if 
at all. There is some evidence which seems to indicate that the action of treat¬ 
ment on spaced plants may extend beyond the germination period and into the 
later stages of plant growth. With regard to the effects of treatment on yield 
it has been shown that.under the conditions of the experiments reported herein, 
plants from treated seed did not outyield plants from untreated seed except 
when sown at a rate compensating for treatment injury and when the plants 
from untreated seed contained a relatively high percentage of loose smut. 
SUMMARY 
(1) The development in recent years of . a number of central or community 
plants for seed-treatment in Indiana and Virginia has stimulated interest in the 
control of the loose smut in wheat by the modified hot-water method and in the 
effects of treatment on the germination, growth and yield of wheat. 
(2) The method of germinating treated seed in moist blotters can not be used 
to determine accurately the effects of treatment on the germination of seed 
when sown in the soil. 
(3) Other factors being equal, the effects of the modified hot-water treatment 
on the germination of wheat are governed by the physical condition of the seed 
coat. 
