May a, X9ax 
Bacterial Leaf spot Disease of Celery 
187 
celery suggests the possibility that the celery disease is caused by the 
same organism. A limited number of inoculations, with the celery organ¬ 
ism have failed to give infection on parsley. Potebnia states that his 
organism does not liquefy gelatin, whereas the celery organism invariably 
causes liquefaction. 
During the seasons 1915-1917 spraying, as a means of controlling the 
disease, was tested at Irondequoit, N. Y. All applications were made 
with a hand sprayer, maintaining a pressure of 25 to 50 pounds. Care 
was taken to cover the leaves thoroughly with the spray material. Several 
rows were sprayed with standard 5-5-50 Bordeaux mixture each season. 
During the last two seasons comparable rows were sprayed with com¬ 
mercial lime-sulphur solution, testing 32 0 Beaum6, which was diluted 
1 part to 25 parts of water. The first application was made soon after 
the plants were transplanted from the seed bed to the field and was 
repeated at intervals of one to two weeks until a few weeks before harvest. 
In 1915, applications were made on August 9, 21, September 1, 10 and 
22; in 1916, on August 12, 19, 28, September 6, 16, 26, and October 6; 
and in 1917 there were a similar number of applications. 
Each season data were taken in October, a few days before harvest. 
The number of bacterial leafspots were counted on representative plants 
occupying opposite positions in adjacent sprayed and unsprayed rows. 
A part of the data is given in Table I. Sets of figures separated by 
horizontal spaces are for opposite and comparable plants. The number 
of spots on each leaf is given separately, the leaves being numbered con¬ 
secutively from the oldest to the youngest fully expanded leaf. 
In 1917 Dr. H. W. Dye of the Cornell Agricultural College made three 
applications of standard 5-5-50 Bordeaux mixture at intervals of about 
nine days at Williamson, N. Y., to celery which already showed the 
bacterial leafspot disease. A few days after the last application the num. 
ber of bacterial leaf spots was counted on 10 sprayed plants and 35 com¬ 
parable unsprayed plants. The average number of spots per plant was 
for the sprayed 214 and for the unsprayed 997. 
The data presented seem to show conclusively that the disease is very 
satisfactorily controlled by spraying with Bordeaux mixture but is not 
controlled with lime-sulphur solution. General appearances of the 
sprayed and unsprayed rows in the field led in every case to the same 
conclusion. 
