A DESTRUCTIVE APPLE ROT FOLLOW- 
ING SCAB.* 
H. J. Eusrace. 
SUMMARY. 
Apple scab was unusually common in western New York dur- 
ing the past season. Early in the fall there developed upon many 
of the scab spots a white mildew-like fungus which caused a 
brown, sunken, bitter, rotten spot. There was no relation be- 
tween the scab fungus and the rot-causing fungus except that 
the scab ruptured the epidermis of the apple, thus making an 
entrance for the rot fungus. 
Traces of the disease could be found when the fruit was on the 
trees, but the greatest damage was done just after the fruit was 
harvested and packed. 
Rhode Island Greening was affected more than other leading 
commercial varieties. Baldwin did not show the effects of the 
disease until late in the fall. 
The trouble was probably more sericus in western New York 
than in the other great apple-growing regions of the country. 
The fungus which caused the rot has been known for many 
years, but always regarded as a saprophyte and of no economic 
importance. 
The disease attacking apples at the time it did, after they had 
been harvested, barreled and ready to be sold, caused an enor- 
mous loss to growers, buyers and dealers. 
Inoculation experiments proved that the fungus is parasitic 
on apple, pear, quince and grape. It is a wound parasite and 
cannot grow through sound epidermis; this explains its associa- 
tion with scab, as the scab ruptures the epidermis. 
*A reprint of Bulletin No. 227. 
