142 
Journal of Agricultural Research 
Vol. XXI, No. a 
held in an inoculation chamber in which the temperature varied from 
59 0 to 90° F. Ten days later there were numerous lesions on both plants. 
On February 12 two small tomato plants were atomized with a water 
suspension from a 34-day-old agar slant culture, one (A) on both leaf 
surfaces and one (B) on only the upper surfaces. These plants along with 
a third plant (C) atomized with distilled water as a control were held 
in an inoculation chamber. Five days later numerous incipient lesions 
were visible on the lower surfaces of the leaves of plant A. The next 
day one lesion was found on plant B. After 11 days, plant A was 
heavily infected, plant B showed only a few lesions and these were on 
rachises and young leaves, and the control plant C was free from infec¬ 
tion. This indicated that infection occurred more readily through the 
lower epidermis. 
A second test yielded similar results. On February 14 two plants 
were atomized with a water suspension of the organism, one (A) on 
both leaf surfaces, the other (B) on only the upper surfaces of the leaves. 
After three days in the inoculation chamber, a few incipient lesions 
were noted on plant A, and by the next day the leaves were thickly 
dotted with incipient lesions. No lesions were found on plant B. Nine 
days after inoculation the coalescence of lesions was causing the death 
of large leaf areas on plant A. A very few scattered lesions had ap¬ 
peared on the younger leaves of plant B, while the older leaves were 
practically free from infection. 
In another test in which 16 plants were inoculated, 8 on the lower 
leaf surfaces only and 8 on the upper leaf surfaces, much more abundant 
infection was secured where the lower leaf surfaces were inoculated. 
These plants were removed from the moist chamber in sets of four at 
intervals of one day, two days, four days, and six days. The infection 
on the plants removed at the end of one day was not quite as heavy as 
on those removed after the longer intervals. Otherwise, no marked 
influence of the humidity factor was noted. 
In all these foliage inoculations, the lesions on the young leaves became 
larger than on the old leaves (Pi. 26, C, D). Rachis, petiole, and stem 
lesions were also obtained, but no fruit infection occurred. In subse¬ 
quent inoculations made during the warmer weather, incipient lesions 
have been detected as soon as 36 hours after inoculation. 
With a tomato culture, characteristic leaf lesions have been produced 
on pepper plants by atomizer inoculation; and with a culture isolated 
from bacterial spot on a pepper fruit, typical foliage infection has been 
secured on tomato. 
With a tomato culture, characteristic leaf lesions have likewise been 
produced on potato plants by atomizer inoculation. These lesions were 
small, sunken, black dots on the lower surfaces of the leaves. 
To summarize, it may be said that tomato foliage infection showed 
up two to five days after atomizer inoculation, that infection occurred 
