New York Agricultural Experiment Station. 307 
REPORT OF THE ASSISTANT HORTICULTURIST: 
INTRODUCTION. 
In addition to the regular statistical work in the garden and orchard, 
a special study of the potato scab has been undertaken the past 
season. Brief notes are added upon other subjects as named below. 
The topics are reported in the following order: 
A study of the potato scab. 
Notes on insects. 
A fungus disease of the cucumber. 
Notes on garden vegetables. 
Notes on fruits. 
Potato Scab. 
A peculiar rusty scab-like appearance of the potato tuber is known 
as the "potato scab." It often extends deep into the body of the 
tuber, causing a considerable loss of substance. The edible qualities 
of the tubers thus affected are not injured, but their market value is 
greatly lessened. 
A German authorityf on plant diseases describes the potato scab as 
" consisting of a greatly increased formation of cork. The connecting 
wall-formed layer of cork cells which form the normal skin of the 
potato are thereby changed, so that the otherwise tabular cork cells 
become distended, round and bladder-like. This tissue lying beneath 
the skin produces new cork cells which force the older cells upward." 
Various theories have been advanced concerning the cause of the 
scab, and not a little study has been given to the subject. At the 
present time little appears to be known concerning the true cause. 
PlowrightJ says: "As usually met with, each scab consists of a cir- 
cumscribed cork formation of the rind of the tuber, as if each spot had 
at some earlier period of its existence been the seat of the injury. 
Most likely this precursory injury will be found due to a fungus of 
*M. H. Beckwith. 
t Soraur's Handbuch der Pflanzen Krankheiten, p. 84, ed. 1874. 
XG. B. Plowright, On Potato Diseases, Gardeners' Chron., Vol. 23, 1885, 
p. 60. 
