392 
Vol. XXI, No. 6 
Journal of Agricultural Research 
Table III. Susceptibility of different varieties of beans to rust infection, with infec¬ 
tion on Tennessee Green Pod as standard and rated ioo per cent —Continued 
pole beans, GREEN pod 
Exper¬ 
iment 
Variety. 
Average 
leaf 
Number of infections 
per square inch. 
Percentage of infection. 
No. 
area. 
Flecks. 
Sori. 
Total. 
Abortive. 
Fertile. 
29 
20 
• 3 2 
II 
McCaslan. ... 
Virginia Cornfield. 
Cut Short. 
Kentucky Wonder.... 
Square 
Inches. 
7.04 
4. II 
5-30 
7.46 
37-87 
36.07 
3 - *9 
5-75 
118.68 
106.09 
104.61 
80.87 
118.68 
106.09 
104.61 
80.87 
28 
9 
26 
28 
1 
1 
Dutch Case Knife. 
Royal Com. 
Powell’s Prolific. 
Creaseback. 
Lazy Wife. 
Horticultural, Pole.... 
5-89 
5-°3 
5 - 9 ° 
4-°3 
7.21 
9.78 
36-85 
146.04 
6.82 
24.32 
2.68 
2.12 
77-50 
66.97 
58.14 
51 . 12 
13-74 
10.87 
77 - 5 ° 
66.97 
58.14 
51.12 
13-74 
10.87 
13a 
Brockton. 
IO.95 
0.21 
•05 
6.77 
80. 70 
1.31 
7 
Tennessee Wonder.... 
IO.O9 
63.IO 
.68 
54-91 
98-93 
•59 
13a 
Marblehead. 
8.76 
. IO 
.01 
e .86 
90.OO 
.26 
POLE BEANS, WAX POD 
Golden Cluster. 
Kentucky Wonder Wax 
Mont d’Or. 
5-84 
5-73 
9.60 
9.80 
10.52 
3 - 8 i 
•45 
4.80 
3 2 - 3 2 
71.22 
67.94 
9-75 
1.32 
100.00 
100.00 
71.22 
67.94 
Everbearing. 
Indian Chief. 
1 
In general the flecks are visible some time before the sori are evident. 
Accompanying the inoculation of Tennessee Green Pod on January 20, 
described previously, in which 143 hours elapsed before the “anlage” 
of the sori were plainly visible, flecks were visible on Hodson Green Pod 
in 112 hours and on Improved Goddard and Tennessee Wonder in 123 
hours. 
On certain varieties the immediate results of the inoculation with 
urediniospores is seen in the production of telia or of mixed sori. This 
is particularly true of Black Valentine and of some of the wax-podded 
varieties, notably Challenge, Flagolet, Golden Eye, Pencil Pod, Keeney, 
Wardwell, and New Kidney. 
The size of uredinia will vary to some extent on a given variety accord¬ 
ing to the degree of infection and crowding. The average size of the 
sorus on different varieties varies greatly, however, ranging from about 
180 n on Dwarf Black Wax to 600 jjl on Tennessee Green Pod (compare 
A and B, PI. 72, and a and d, Plate 69, B). 
The duration of the incubation period is modified by environment, 
especially temperature, but in different varieties under similar condi¬ 
tions a variation of several days may occur. Such variations have 
