Rt Pe oe 
New York AGRICULTURAL EXPERIMENT STATION, 123 
ple trees often causing severe injury. Orchardists had been familiar 
with the disease for years, but the cause and remedy were wholly 
unknown. In the course of the investigation it was discovered that 
the primary cause of canker is a parastic fungus, Spheropsis 
malorum, well known as the cause of the common black rot of 
apple fruit. Typical cankers were produced by artificial inocula- 
tion of apple wood with pure cultures of the fungus obtained from 
rotten apples. The fungus was also successfully inoculated onto 
pear, quince and hawthorn wood. The treatment suggested for 
canker consists in the removal of diseased limbs, thorough spraying 
with bordeaux mixture, scraping and washing the trunks and larger 
branches with bordeaux mixture or with a mixture of whale oil 
soap, slaked lime, wood ashes and water, and the planting of re- 
sistant varieties. 
In the autumn of 1902 the apple crop was damaged to an enor- 
mous extent by an unusual form of decay called pink rot. Many 
thousands of barrels of apples were completely ruined soon after 
they were harvested. An investigation made by the Station showed 
the cause of the trouble to be a white or pinkish mildew! which 
took possession of the spots caused by the common scab fungus and 
transformed them into brown, sunken, bitter, rotten spots. It was 
proven that this pink mildew was unable to force its way through 
the unbroken skin of the apple and that its principal avenue of 
entrance is through breaks in the skin caused by scab fungus. This 
fact being determined the remedy was plain, namely, thorough 
spraying with bordeaux mixture to prevent scab.1® 
Other apple diseases investigated are the following: 
(1) Two decays of stored apples!7 — one a rot similar to pink 
rot but caused by a different fungus,'* and the other a core decay 
the cause of which was not definitely determined. 
(2) The fruit spot, which is characterized by brown, sunken 
spots on the surface of the fruit with pockets of brown, corky tissue 
underneath. It was shown that neither fungi nor bacteria are con- 
cerned in this trouble.’ 
(3) Blisters on the under surface of apple leaves caused by late 
spring frost, hence called “ frost blisters.’?° 
* Cephalothecium roseum Corda. 
* Bul. 227 (1902); same in Rpt. 21:141-162. 
* Bul. 235 (1903); same in Rpt. 22:108-116. 
** Hypochnus sp. 
* Bul. 164:215-219 (18900); same in Rpt. 18:176-181. 
” Bul. 220 (1902); same in Rpt. 21:57-67. 
