270 
Journal o f Agricultural Research 
Vol. XXIX, No. 6 
of erect, as previously mentioned, and 
were yellowish in appearance. Some 
of these later developed a somewhat 
stiff appearance with a rather bluish- 
green color. A high percentage of the 
plants which matured from the in¬ 
oculated seed developed loose-smut. 
(Table III.) 
On February 13, 1924, another set 
of dehulled seed of Han River from 
depths of sowing on the emergence of 
the seedlings. It seemed probable 
that the deeper sowing would produce 
poorer stands, judging from previous 
results, both as to stands and the 
effects of the fungus on the young 
seedlings. Seed of three varieties of 
barley—Tennessee Winter, Han River, 
and Nakano Wase—was dehulled and 
25 inoculated and an equal number of 
Table III .—Effects of Ustilago nuda on the emergence of barley seedlings from 
dehulled seed , and the occurrence of loose-smut in the surviving plants 
Variety 
Treatment 
Number 
of 
seed 
sown 
! 
Number 
of 
plants 
emerged 
Per 
cent of 
emer¬ 
gence 
Number 
o f 
plants 
matured 
Number 
of 
plants 
smutted 
Per 
cent of 
smutted 
plants 
Texas Winter__. 
Inoculated..... 
56 
3 
5. 36 
3 
3 
100 
Do_ 
Uninoculated . _ 
57 
20 
35. 09 
11 
0 
0 
Han River_ 
Inoculated 
62 
7 
11. 29 
5 
4 
80- 
Do_ 
Uninoculated_ 
61 
57 
93.44 
57 
0 
0 
Do__ 
Inoculated ... 
50 
44 
88. 00 
Do_ 
Uninoculated_ . . 
50 
46 
92. 00 
the 1922 crop was sown about ^ of an 
inch deep in a flat in the greenhouse. 
The seedlings emerged but slightly 
better from the uninoculated seed. 
Most of the plants in this flat were 
used for infection studies and were 
not grown to maturity, so there are 
no smut records available. (Table III.) 
The results given in Table III are 
very striking. Even though the stands 
of plants were much poorer from in¬ 
oculated seed, those plants which sur¬ 
vived showed a high percentage of 
loose-smut. Emergence of seedlings 
in the flat where the seed was sown 
M inch deep was much better than 
was the emergence from seed sown 2 
inches deep on the benches. These re¬ 
sults led to the belief that the degree 
of injury to the seedlings by infection 
would be indicated to a certain extent 
by the ability of the infected seedlings 
to emerge when the seed was sown at 
different depths after inoculation. 
A set of experiments was arranged 
in which the seed was spaced carefully 
in the rows and covered at uniform 
depths of % and 1^ inches, respec¬ 
tively, to determine the effects of these 
uninoculated seed of each was sown 
in flats in the greenhouse on February 
25, 1924, at each of the two depths— 
% of an inch and inches. A com¬ 
pact soil with little organic matter was 
used. Four days previous to this, 50 
seeds each of inoculated and unin¬ 
oculated Han River barley were sown 
in a flat of loose organic soil in the 
same greenhouse. 
Through subsequent observation, it 
was found that there was a striking 
difference in the percentage of emer¬ 
gence of seedlings from inoculated 
seed sown at the two different depths, 
except in the loose soil, while there was 
very little difference in the emergence 
from uninoculated seed sown at differ¬ 
ent depths (PI. 3, A to H, PI. 4, A to D). 
The surviving plants from the inocu¬ 
lated seed of Tennessee Winter and 
Han River showed a high percentage 
of loose-smut (PI. 5, A and C; PI. 6, 
A and G; PI. 7, A); Nakano Wase from 
inoculated seed remained smut-free, 
as did all the plants from uninoculated 
seed (PI 5, B and D; PI. 6, B and D, 
and PI. 7, B). (Table IV.) 
EXPLANATORY LEGEND FOR PLATE 3 
Infection of barley seedlings from dehulled seed by Ustilago nuda , and emergence of seedlings from seed 
sown at different depths in flats in the greenhouse on Feb. 25, 1924. 
Tennessee Winter: 
A. —Inoculated, sown % of an inch deep; 56 per cent emergence. 
B. —Uninoculated, sown % of an inch deep; 88 per cent emergen e. 
C. —Inoculated, sown 1 Yi inches deep; 32 per cent emergence. 
D—Uninoculated, sown \ l A inches deep; 84 per cent emergence. 
Nakano Wase: 
E. —Inoculated, sown % of an inch deep; 60 per cent emergence. 
F. —Uninoculated, sown % of an inch deep; 92 per cent emergence. 
G. —Inoculated, sown \ X A inches deep; 28 per cent emergence. 
H. —Uninoculated, sown 1J^ inches deep; 92 per cent emergence. 
