May 3,1924 
Effect of Moisture on Seed-Borne Bean Disease 
491 
of the evidence concerning the presence of wilt symptoms among the bean plants 
previously reported ( 9 ). From a practical standpoint, the amount of seed pro¬ 
duced constitutes a better index of the effect than observations on the numbers of 
diseased plants. 
The effect of the disease and moisture additions on the Redfield beans, it is re¬ 
vealed in the figures, is reflected also in the bean yields and the differences fol¬ 
low the same general trend that was indicated by observations on the growing 
beans, that is, the plants from seed treated with moisture gave a higher percentage 
of disease and a lower yield of seed than the plants from seed not treated with 
moisture. 
On the other hand the clean seed shows the same correlation only in a minor 
degree. The plants from the selected seed acted more as a unit, all ripening their 
seed at approximately the same time whereas th£ plants from the Redfield seed 
ripened unevenly; at the time of harvest green beans and flowers were noticeable 
to the approximate extent of 10 per cent in all rows except one of those planted 
to untreated seed, which for some unknown reason ripened uniformly. There 
was evidence of the wilt among these immature beans. 
Considering the average yield of 671 gm. as 100 per cent, the average reduction 
in crop, apparently due to the addition of moisture to the seed before planting, 
is 30.3 per cent, ranging from 51.3 per cent for the water treatment to 6.9 per cent 
reduction from treatment with bean culture No. 162. 
Table I .—Navy bean yields from plats at Redfield f S. Dak. f in 1922 
Treatment« 
Redfield 
seed & 
Clean 
seed c 
None........... 
Grams 
710 
Grams 
809 
Water..... 
237 
710 
Ashby broth...... 
525 
802 
Soil broth..... 
511 
767 
Inoculated soil..._.... 
632 
824 
Commercial culture_________ 
405 
752 
407 Wisconsin culture_______ 
469 
724 
342 United States Department of Agriculture culture...,... 
412 
824 
162 United States Department of Agriculture culture.... 
625 
767 
o With the exception of the inoculated soil, all treatments were applied in the liquid form at the rate of 
approximately 10 cc. per 600 gm. of beans. 
6 Harvested Aug. 24, 1922. 
* Harvested Aug. 19, 1922. Each figure is the average of two plats. 
EXPERIMENTAL WORK IN 1923 
PREPARATION AND PLANTING 
The experience of 1922 led to the planning of more extensive work for 1923 
under dry land, humid, and irrigated soil conditions. It was hoped to deter¬ 
mine the conditions favorable for the development of disease in connection with 
inoculation with legume bacteria, the extent of these conditions, and additional 
proof of the efficacy of the measures for control. 
The seed employed in the major portion of the experiments were progeny of 
the Redfield seed used in the former experiment. At Mandan, N. Dak., and 
Rosslyn, Va., a badly diseased mixture of commercial bean seed was used. Seed 
of Robust bean, cowpeas, and tepary beans were also planted with the idea of 
establishing the presence of disease amongst them and the stimulation of such 
disease if present by the addition of moisture. At each place the beans were 
planted in equal length rows, but owing to variations in the sizes of plots at the 
different places, the rows of the different plots are not comparable. As far as 
possible, rows were made equivalent to one four-hundredth of an acre. Each 
of the treatments given below was duplicated at each place. 
