An Apple Rot Due to An 
Undescribed Species of Alternaria. 
BY B. O. LONGYEAR. 
history and distribution. 
Among* the comparatively few diseases of orchard fruits, which 
occur in the state of Colorado, probably the most widely distributed 
and common one is a decay of apples and pears due to an appar¬ 
ently undescribed species of Alternaria. This decay was first met 
with by the writer at the Michigan Agricultural Experiment Station 
in the winter of 1904. While investigating the decays of stored 
apples at that place, a single specimen was found showing a decay 
of unfamiliar appearance. A tube culture was made from spores 
obtained by placing this specimen in a moist chamber for several 
days, and inoculations of sound fruit were made which demon¬ 
strated the ability of the fungus to induce the decay. 
At this Station the fungus was first reported in November, 
1902, and specimens were secured for study by Professor W. Pad- 
dock, who recognized the fungus as being a species of Alternaria. 
Pie also conducted some inoculation experiments with the fungus 
and made the first report of it in the Experiment Station report of 
1904. Investigation shows it to be of quite common occurrence in 
this State and it has been also found in the core cavity of one 
variety of apples grown in California. 
Thus, while this decay evidently occurs over a wide range, the 
fact that it has thus far been unnoticed, indicates that it is probably 
not destructive to any extent in other regions. 
CHARACTER OR THE DISEASE ON THE APPUE. 
In the case of the apple, so far as studied, the fungus is con¬ 
fined to the fruit, its most common point of attack being at the 
blossom end. The affected fruits usually show a dark purplish 
brown, slightly sunken area at the base of the sepals. This area 
may remain small and scarcely noticeable for a long time, but when 
the fruit is placed in storage it is apt to increase in extent until the 
fruit is entirely decayed. During the past season specimens were 
found in which the blossom end of the apple was cracked open and 
a considerable area of the discolored tissue surrounded the rupture, 
but this is not the usual manner of attack. It seems probable in 
