New York AGRICULTURAL EXPERIMENT STATION. 139 
beneath a layer of bordeaux mixture. Craig? states “ that it is true 
that a scab spot will cease to enlarge if thoroughly covered with 
bordeaux mixture”? and Warren? reports that the spot will continue 
to grow though covered with spray. 
These reports appear to have been based upon general observa- 
tions. Growers frequently want to know definitely about the mat- 
ter as it has an important bearing upon the advisability of a late 
summer spraying in seasons when scab is especially severe. That 
information based upon experimental data might be secured, the 
following tests were undertaken: 
On August 1, a number of apples showing well defined scab spots 
were found upon a Carolina June tree. They were conspicuously 
marked and the scab spot or spots to be under observation were 
numbered by marking upon the fruit with water proof ink and then 
making careful measurements of the spots. Part of the apples were 
thoroughly sprayed with bordeaux mixture, the others being re- 
served for checks. The bordeaux was the 5-5-50 formula and ap- 
plied very thoroughly especially on the scab spots. 
Frequent examinations were made of these apples and measure- 
ments and notes taken. In all but one case the spots that were 
covered with the bordeaux mixture continued to enlarge, as did all 
of the spots that were marked for checks. 
Similar tests were made on August 3 with Rhode Island Greening 
and Fall Pippin. On August 6 with the same varieties and on 
August 30 with Rhode Island Greenings. In every one of these 
tests all of the scab spots enlarged after they had been covered with 
a thick coating of bordeaux mixture. 
These results are what would be expected, as it is known that the 
scab fungus grows in the fruit beneath a thin outer layer known as 
the epidermis. See Plate IX, fig. 2. The margins or growing 
portion of the scab spot is then protected and beyond the reach of 
the action of the bordeaux mixture. 
* Craig, John, and Van Hook, J. M. Pink rot an attendant of apple 
scab. Cornell Sta. Bul. 200, p. 167. 
* Warren, G. F. An apple orchard survey of Wayne County, New York. 
Cornell Sta. Bul. 226, p. 3309. 
