34 Report oF DEPARTMENT OF BACTERIOLOGY OF THE 
only about one-third of these fields that they were present ia 
sufficient numbers to produce an inoculation of any consider- 
able number of the young alfalfa plants. | 
An attempt to supply the germs by applying pure cultures of 
Ps. radicicola to the seed, drying and sowing, resulted in an 
almost complete failure. 
Applying soil from an old alfalfa field at the rate of 150 to 
300 pounds per acre invariably produced an abundant inocula- 
tion on these experimental plats. 
While but 15 of the 67 experimental plats produced a success- 
ful crop of alfalfa without inoculation, 48 adjacent plats where 
inoculating soil had been applied produced successful crops. 
Accordingly alfalfa growing on 33 of the 67 fields which were 
tested was changed from a failure to a success by the applica- 
tion of inoculating soil. | 
EXPERIMENTS BEGUN IN 1907. 
During the season of 1907 soil from our alfalfa field was 
furnished for 49 experiments and the attempt was made to test 
on that number of fields the need of inoculation in connection 
with alfalfa growing and the results of supplying this inocula- 
tion by means of inoculating soil. Our experience of this sea- 
son is a duplicate of that of the two preceding years in that 
mistakes were made in laying out the experiments in a number 
of fields and in other cases the necessary data could not be 
obtained after the experiments had been started. 
The attempt has been made to exclude from our calculations 
all experiments in which the plats were so located or handled 
as to render the results questionable or where the data are 
incomplete. Accordingly the present publication gives the re- 
sults from only 33 of the 49 experiments., While it is true 
that some of the 16 experiments which are not included were 
failures, others produced successful stands of alfalfa on some 
' of the plats. They have all been rejected solely: because the 
factors which produced the results could not be determined 
from the data at hand. 
