92 
Journal of Agricultural Research 
Vol. XXVIII, No. 1 
Table XIV shows that although the plants from the untreated seed contained 
an average of 5.8 per cent of loose smut, they outyielded those from the treated 
seed by 7.1 bushels per acre. The average from 7 seed lots in the two years shows 
that treated seed yielded 4 bushels per acre less than untreated, although plants 
from the latter contained 7.4 per cent of smutted heads. 
A comparison of the yields for the two years will show that reduction in yield 
from treated seed in 1922, amounting to 7.1 bushels per acre, is approximately 
7.5 times the reduction of 0.95 bushels per acre in the yield from treated seed in 
1921. It has been shown before (Tables IV and V) that the amount of seed injury 
resulting from the modified hot-water treatment is intimately related to the 
percentage of seed coats broken in threshing. Investigators have shown, more¬ 
over, that the amount of damage suffered by seed coats in the process of threshing 
is markedly greater in dry years than in wet years. Nobbe (7) first pointed out 
that the drier and more brittle the crop, the greater was the injury from threshing. 
Volkart (14) made similar observations and Wallden (15) also noted that in dry 
years the cracking of seed coats by threshing machines was more prevalent. In 
this connection, therefore, a study was made of the climatologic data for June 
and July, in 1920 and 1921, for the localities which supplied the seed used in the 
yield experiments in 1921 and 1922, respectively. The seed used was ripened, 
harvested, and threshed during June and July and the effects of weather conditions 
on the seed coats occurred in those months. The climatologic data are presented 
in Table XV. 
Table XV.— Temperature and rainfall during June and July f 1920 and 1921 , 
in the localities in which was grown the seed wheat used in the yield experiments 
of 1921 and 1922 , respectively 
County 
State 
Lot 
number 
Departures from normal 
Year 
Temperature 
Rainfall 
June 
July 
June 
July 
Hancock. 
Shelby. 
Rush. 
Indiana. 
.do. 
.do. 
7 
13 
16,17 
19 
26,27 
1920 
..do... 
1921 
. .do... 
. .do... 
°F. 
-1.0 
-1.0 
+2.4 
+5.9 
+1.7 
°F. 
-1.7 
-2.1 
+4.9 
+5.4 
+2.4 
Inches 
+1.52 
-0.61 
-0.66 
-1.12 
-0.73 
Inches 
+1.29 
0 
-0.10 
+0.30 
+0.14 
Hancock. 
Arlington. 
.do. 
Virginia. 
Reference to Table XV shows abnormally low temperatures and a rainfall 
slightly above normal in June and July, 1920, in the localities which supplied 
the seed used in 1920-21. For the State of Indiana, as a whole, July, 1920, 
was one of the coolest on official record. In striking contrast, the temperatures 
were abnormally high and the rainfall below normal in June and July, 1921, in 
the counties supplying the seed used in 1921-1922. June, 1921, was the 
warmest on official record in Indiana and the average temperature of July, 
1921, has been exceeded only twice in 34 years. It was the hottest July in 
Virginia since 1901. In the light of these data, the condition of the seed coats 
of wheat grown in 1920 and 1921 was examined carefully. It was very evident 
that the latter had sustained considerably more injury in threshing. It is inter¬ 
esting and noteworthy that the weather conditions, through their influence on 
the seed coats in withstanding threshing injury, may be potent factors in deter¬ 
mining the amount of seed injury and subsequent yield which result from 
treatment of the seed by the modified hot-water method. 
Attention is directed to the parts of Table XIV dealing with the average 
yields on the east and west sections of the plats. It will be noted that the 
