TREATMENTS OF SEED WHEAT FOR LOOSE SMUT 13 
on the weight of grain, the test weight per bushel was taken on all 
of the wheat grown from the seed of the five lots. In the description 
of the plan of this experiment it was noted that each of the fire 
plats was divided into two sections, which were duplicates. In 
making the study of weight of grain, wheat from the duplicate rows 
in the two sections was thoroughly mixed. This was necessary 
in order to have a sufficient quantity to fill the cup of the tester. 
This procedure was carried out for the grain grown from untreated 
and treated seed of each lot in each of the five plats. The results are 
presented in Table 7. 
Table 7 shows that the weight of grain from treated seed was 
slightly greater than that from untreated seed where the modified 
hot-water method was employed and slightly less where the single- 
bath method was used. In all instances the differences were very 
slight. Because of varying amounts of injury from treatment, 
especially in the case of the modified hot-water method, the quantity 
of viable seed frequently is reduced, and a thin stand results. Under 
this condition the plants from treated seed might produce grain of 
higher weight per bushel than the plants from untreated seed, but 
without relation, however, to any direct effects of treatment. 
With regard to the relative effectiveness of the various single-bath 
treatments, a study of the foregoing data shows that the treatments 
at 48° C. for 1 hour and 50 minutes and at 49° for 1 hour and 35 
minutes gave the most satisfactory results. They controlled loose 
smut completely and bunt effectively, and the reductions in germi- 
nation and yield were relatively small. The treatment at 48° for 1 
hour and 40 minutes slightly surpassed the treatment at 48° for 1 
hour and 50 minutes in most respects, but it was less effective in 
controlling loose smut. Xone of the treatments at 47° appeared to 
have particular advantage. Those of shorter duration failed to 
control either loose smut completely or bunt effectively, or both. 
Moreover, all of the treatments at 47°. especially those of longer 
duration, reduced the yield more than the treatments noted above. 
In view of these facts the following experiments with the single-bath 
method were confined to the treatments at 48° for 1 hour and 50 
minutes and at 49° for 1 hour and 35 minutes. 
EFFECTS OF SINGLE-BATH HOT-WATER TREATMENTS IN 1923-24 
GERMINATION IX RELATION TO INTEGRITY OF SEED COAT 
In a previous article {15) the writer showed that the condition of 
the seed coat is a most important factor in determining the reduction 
in germination resulting from the modified hot-water treatment. 
When the seed coats of wheat were unbroken the modified treatment 
reduced the germination very little, if at all; but when the seed coats 
were broken, the reduction in germination always was high, especially 
when the break was over the embryo. In order to determine the 
effects of the single-bath method on germination in relation to integ- 
rity of seed coat, an experiment was conducted with hand-threshed 
seed. Five varieties, Currell (C. I. 3326), Forward i.C. I. 6091), 
Fultz (C. I. 1923), Purplestraw (C.I. 1915), and Stoner (C. I. 29 
were used. Each variety was divided into five lots of 60 seeds each. 
The seed coats were left unbroken in the first lot. In lots 2 to 5 a 
small part of the coat was very carefully broken on February 7. 1924. 
with a sharply pointed needle in the following locations : Lot 2, directly 
