1020 



Walter H. Burkholder 



martii phaseoli was used. Six rows were inoculated, with a check row 

 left between each two treated rows. All seed used in the experiment 

 was inoculated with the root-nodule organism. 



During the summer the plot was cultivated twice and weeded. At 

 podding time a slight difference could be distinguished between the check 

 rows and the rows of infected plants. That this should occur in 1918 

 and not in 1917 was due to the lower ground on which the plot was 

 located in 1917 and to the general raininess and cloudiness of that growing 

 season. The plot was planted on June 4, after which rain fell on the 

 following dates: June 6, 7, 10, 11, 12, 13, 14, 21, 22, 23, 25, 28, and 

 29 — a total precipitation of 3.05 inches. Thus a sufficient amount of 

 soil moisture was present during the infection period. In July rain fell 

 on the following dates: July 1, 3, 5, 9, 10, 11, 17, 24, 29, and 30 — a 

 total precipitation of 4.55 inches. During August, when the pods are 

 formed, there was less than half as much precipitation as in the month 

 of August, 1917; rain fell on the following dates: August 4, 5, 8, 10, 

 14, 24, 26, 28, 29, and 30 — a total precipitation of 3.76 inches. The 

 plants were harvested in the first part of September. The results of 

 this experiment are shown in table 4: 



TABLE 4. Effect of the Dry Root-Rot on the Yield of the Bean during the 



Season of 1918 



* The reduced yield was calculated as in table 3 (page 1024). 



The experimental plot used in 1918 was an apparently level piece of 

 ground, nevertheless it may be seen that the yield near the center was 



