336 
The Ohio Naturalist. 
[Vol. XI, No. 6, 
The fungus is also present on .the water sprouts (Fig. 4) and 
fruit spurs where it forms tan-colored cankers. These cankers on 
the water sprouts are variable in size, often attaining a length of 
two inches, and a width of about one-half inch. The cankers on 
the fruit spurs are smaller, being usually about a quarter of an 
inch in diameter. However, the cankers are more numerous than 
on the water sprouts and often give the fruit spurs a very rough, 
ragged appearance due to the cracking of the cankered tissue. 
Sometimes the cracks may entirely separate the infected from 
healthy tissue, and then the canker wound will be healed by the 
growth of the new tissue which crowds away the infected bark. 
The pycnidia are found scattered over the entire canker surface 
and the spores therein are similar to those found on the fruit. 
The leaves, when infected with Phyllosticta solitaria, show 
small yellow spots about a sixteenth of an inch in diameter. In 
the center of these irregular spots there usually can be found one 
or more pycnidia which contain the spores. The presence of the 
spots on the leaves are often lacking, especially when the foliage 
has been protected by proper spraying. 
From the trees observed in this state, it is evident that very 
little infection comes from the infected leaves, but the perennial 
cankers on twigs, with their numerous pycnidia, are the great 
source of infection. The blotches, which give the apples their 
unsightly appearance, begin to appear late in July or in the early 
part of August and increase in size until harvesting (Fig. 2). 
These apples when kept in storage soon decay, because, through 
their injured epidermis other fungi enter. 
As to the control of the apple blotch, it' is reported by several 
of the fruit growers that spraying will control this disease. How- 
ever, it has been observed that the blotch was prevalent to a great 
degree on certain trees that were well sprayed. The blotched 
apples in such cases would tend to discredit the use of sprays were 
it not for the fact that the trees were usually not well pruned, 
and hence the cankers were allowed to send forth their spores 
unhindered. It appears that spray treatment must extend 
throughout the season after the manner of sprays for bitter-rot. 
Thus it is clearly seen that while spraying is a great factor in the 
control of the apple blotch, pruning plays just as important a 
role in checking a disease which is costing many bushels of apples, 
and which, if not checked, will ruin some of the choice crops in 
this state. 
Date of Publication, April 3, 101 1. 
