Indiana Plant Diseases. 189 
Fig. 2. Apple seab. 
the leaves and fruit of Chenango, Benona, N. W. Greening, Jonathan, and 
Ben Davis, while there was very little on the Transparent and Duchess. 
Warly infection of the fruit caused much cracking and malformation which 
was followed by secondary rots late in the season. 
Observations upon varietal susceptibility by Burkholder indicate that the 
varieties Moyer’s Pride, Salome, Ben Davis, Winesap, Rome Beauty, Delici- 
ous and Fameuse are very susceptible to scab, while resistance is shown 
by the varieties Yellow Transparent, Early Harvest, Stark, Flore Belle, 
Bellflower, Stayman Winesap, York Imperial, Black Twig and Grimes 
Golden, 
Black rot due to Physalospora cydoniae occurred generally throughout 
the state on apple foliage. In one orchard in May the extreme prevalence 
of the frog-eye leaf-spot on trees badly affected with blotch was of interest 
because the black rot fungus is very commonly present in the old blotch 
‘ankers. In an orchard near Vincennes a local out-break of the frog-eye 
leaf-spot was very evidently associated with a limb which probably had 
been killed by fire-blight and was harboring the black rot fungus. On the 
other hand this leaf-spot was also present on young, well cared-for trees. 
June 25 the leaf-spot was noted to be especially bad on the varieties Ben 
Davis and Jonathan. The fruit rot of the blossom-end type as well as 
the type following blotch, scab and worm injury was very common late 
in the season. 
Fire blight due to Bacillus amylovorus was very common on apple trees 
near blighted pear trees. Because of the prolonged growing season this year 
the attacks of fire blight continued well into the summer. July 2 this dis- 
ease was found rather prevalent on certain varieties in a large orchard 
near Vincennes. An orchardist at Laurel found that thorough spraying for 
aphis control was effective against blight and that improper spraying re- 
sulted in an increased amount of blight. 
Sooty blotch and fly speck (Leptothyriwm pomi) were very Common on 
certain varieties. 
