WALNUT BLIGHT IN THE EASTEKN UNITED STATES. 5 
inoculation by needle puncture and two inoculated twigs having 
characteristic cankers. The control, which was punctured with a 
sterile needle, is shown at the right. The needle punctures in the con- 
trol barely showed at this time, 30 days after inoculation. 
Subsequently the organism was reisolated from a number of these 
inoculated nuts, and the cultural studies so far made from these 
isolations coincide with those made by Smith x and by Pierce. 2 
TIME OF INFECTION. 
During the season of 1916 infection apparently took place about 
the last of May in the cases under observation. At this time the 
nuts were very well developed, approximately three-fourths to 1 
inch in diameter, and although there was a slow increase in the area 
of the infection points through July and some coalescing of these 
spots to form larger ones, the disease did not begin to work 
deeply into the tissues until about the middle of August, by which 
time the shell had formed and hardened. By the end of the 
season the husks had become black, watery, and rotten, staining 
the shells and clinging to them when allowed to dry. The develop- 
ment of the nuts did not seem to be affected materially, if at all. 
The growers interviewed were unanimous in stating that infection 
was usually late and that no material shortage of crop resulted there- 
from. However, the former part of this statement probably could 
be applied only to the time at which the infection became so evident 
as to attract the attention of ordinary observers. 
In the California orchards the greatest loss from infection occurs 
at or near blooming time. Infection is serious in proportion as the 
weather is moist at that time. A dry, clear spring means little, if 
any, blight, whereas serious infection is associated with moist, foggy 
spring weather. The disease as observed in 1916 in Pennsylvania, 
Delaware, and the District of Columbia resembled closely the severe 
late infections described by Smith. 1 
CONTROL OF WALNUT BLIGHT. 
Various attempts to control this disease by spraying and by soil 
applications have been made in California, and although some suc- 
cess has attended the spraying experiments it has not been of such 
degree as to extend any material encouragement to the commercial 
orchardist. That spraying will be of no value under eastern condi- 
tions can not be assumed from this fact, however, owing to the dif- 
ference in the infection periods previously referred to. Neverthe- 
less, spraying to control diseases of bacterial origin has never been 
1 Smith, R. B., Smith, C. O., and Ramsey, H. J. Op. cit 'Pierce, N. B. Op. cit 
