6o2 
Journal of Agricultural Research 
Vol. XXIV, No. 7 
Tabl^ I .—Results of exposing slides on airplanes —Continued 
Date. 
1 
Altitude (above ground.) 
Length of exposure. 
Spores and pollen grains on 
slides. 
Stem rust, uredmio- 
spores. 
6 
Altemaria spores. 
Helminthosporium 
1 spores. 
Miscellaneous spores. 
Pollen grains. 
TotaL 
Feet. 
Minutes. 
July 19 
10,000 
5 
44 
20 
<n 
8 
n 
xo 
.... 
2,000 
xo 
»ab 
n 
ab 
n 
n 
n 
.... 
July 22 
3 .500 
25 
198 
27 
ab 
.... 
ab 
24 
.... 
St 000 
. 30 
57 
20 
n 
4 
n 
2 
.... 
July 23 
4»500 to 
30 
7 
XX 
n 
.2 
n 
5.000 
...do. 
5,000 to 
35 
S 
6 
57 
Z 
so 
25 
X 44 
7.500 
.. .do. 
Control. 
0 
June 25 
500 
2 
2 
2 
4 
.. .do..... 
X, 000 
2 
2 
s 
27 
34 
...do. 
1,500 
2 
3 
8 
X 
X 2 
2,000 
2 
3 
5 
X 
9 
Location. 
West of Pine Bluff, Wyo. 
Grand Island, Nebr. 
Big Springs, Nebr., to Sidney, Nebr. 
Sidney, Nebr., to Bushnell, Nebr_ 
Lodgepole, Nebr., to Brule, Nebr.... 
Brule, Nebr., to North Platte, Nebr. 
North Platte, Nebr. 
Curtiss Field, St Paul, Minn. 
_.do.. 
_do . 
_do. 
* Puccinia tritiema and P. coronata. * ab=Abundant (over aoo). * n*»Numerous (loo to 200). 
Table II .—Results of exposing slides in a spore trap on the wing of an airplane and by 
hand from the cockpit for five minutes ^ at Fort Crook t Nebr., fuly 22, ig2i 
Spores and pollen grains on slides. 
Altitude. 
Manner of exposure 
Stem rust, 
uredinio- 
spores. 
Leaf rust, 
uredinio- 
spores. 
Alter- 
naria 
spores. 
Helmin¬ 
thospor¬ 
ium 
spores. 
Miscel¬ 
laneous 
spores. 
Pollen 
grains. 
Feet. 
10,500 
In spore trap. 
0 
13 
2Z 
0 
5 
2 
10, 500 
By hand. 
X 2 
x 8 
147 
X 
46 
0 
8,000 
In spore trap. 
IS 
2 
90 
5 
7 
8,000 
By hand. 
56 
13 
735 
2 X 
1 
I ab 
xs8 
7,000 
In spore trap. 
14 
x 
65 
5 
X 
7.000 
By hand. 
x8 
17 
435 
IS 
ab 
36 
6,000 
In spore trap. 
7 
X 
60 
X 
xz 
xo 
6,000 
By hand,..;. 
6 
IS 
ab 
XX 
ab 
50 
3. 500 
In spore trap. 
14 
0 
2 
22 
2 
3. 500 
By hand. 
14 
0 
ab 
19 
ab 
XX 
2,000 
In spore trap. 
4 
6 
3 
3 
2, 000 
By hand. 
32 
35 
ab 
63 
ab 
17 
1 ab=» Abundant (over 200), 
