386 
Journal of Agricultural Research 
Vol. XXI, No. 6 
Kentucky Wonder bean in San Diego county and prevents the growing of this valu¬ 
able crop late in the fall. Treatment both with Bordeaux mixture and finely ground 
sulfur was tried, but unfortunately neither material gave any appreciable control of 
the disease. 
D. C. Milbratli 1 is quoted as follows: 
In Los Angeles county, especially in the San Gabriel Valley, rust developed so 
rapidly on beans during the past week that some fields have been abandoned. This 
is the case particularly with Lady Washington and French varieties. 
Until recently there has been little specific information in literature on 
the relative susceptibility of bean varieties to rust. 
Duggar ( 2 ) states that great differences exist in the susceptibility of 
varieties among both dwarf and pole sorts and suggests that the selec¬ 
tion of resistant varieties would seem to be possible. 
Gassner (5) noted a difference in the susceptibility of 2 varieties of 
beans in South America and later planted 15 varieties in a field test. 
These were inoculated with rust spores, and wide variations in suscepti¬ 
bility were seen. Three of the varieties were severely injured, while the 
remainder were only moderately, slightly, or not at all affected. 
Jordi (7), in Europe, took field records on five varieties of pole beans 
with respect to severity of rust, using the cipher 1-10 to indicate the 
state of susceptibility. Four of the varieties were susceptible, being 
rated 7-10, while one, Klosterfrauen, was resistant, being rated only 
0.5-1. 
In the Plant Disease Bulletin for September 15, 1918, W. J. Morse (9) 
lists 17 varieties of beans with respect to their susceptibility to rust in 
Maine. Seven of the varieties were severely attacked, while the other 10 
developed only slight infection or none. 
In a previous publication ( 4 ) the writers have described the field be¬ 
havior of a large number of bean varieties with respect to their suscepti¬ 
bility to rust. Very marked variations were found together with great 
curtailment of productivity, some of the most susceptible varieties being 
complete failures. 
It is the purpose in this paper to describe more fully the various 
phenomena found in studies of rust infection and development on cer¬ 
tain varieties of beans, especially under greenhouse conditions. 
EXPERIMENTAL METHODS 
Considerable preliminary work was devoted to the development of a 
technic. A standard dosage, method of inoculation, and uniformity in 
the records of infection were recognized as some of the first requisites. 
One of the greatest difficulties in this connection lies in the material 
itself. The pathogene, together with other Uredinales, can not be 
grown apart from the living host, and in consequence the pure culture 
1 Milbrath, D. C. [FIELD notes.1 In U. S. Dept. Agr. Bur. Plant Indus. Off. Cotton, Truck, Forage 
Crop Disease Inves. News Notes, v. 7, no. 22, p. 5. 1918. Mimeographed. 
