418 OHIO EXPERIMENT STATION: BULLETIN 214 
PEACH 
Anthracnose. An anthracnose fungus (Gloeosporium laeticolor Berk.) has 
been described upon the fruit of peach and has been found in Ohio, though 
rarely. Careful spray treatment as for scab should be successful against this 
disease. : 
Crown Gall. This is 
a very contagious 
disease of the peach 
and ‘of other plants, 
notably daisy, rasp- 
berry, and blackberry, 
due to a_ bacterium 
(Bacterium tumefaciens) 
Sometimes it produces 
excrescences -and en- 
largements upon _ the 
root and branches of the 
affected plant. More 
commonly the galls are 
found upon the stems 
just below the surface 
of the earth. These vary 
in size and in location, 
even occurring upon the 
small roots, and less 
frequently upon the stem 
at some distance above 
the ground. In some 
recent experiments (Bul- 
letin 104) it was found 
that the gall trouble 
became communicated 
from diseased rasp- 
berries to peach trees 
set in the plantation. 
In some instances the 
loss from crown gall 
es a 
Fig, 68. Root of nursery peach tree attacked by crown gall. 
has been large and there is, in my judgement, no other 
disease common to several of our fruit trees that is so 
threatening in its ravages. The peach trees attacked in 
most cases perish without producing fruit. This applies 
when the trees are affected at nursery age—the usual 
condition. Purchasers cannot afford to set such dis- 
eased trees nor nurserymen to ship them. As yet the 
only treatment that we can recommend is to dig out and 
burn the diseased trees, and to avoid planting affected 
stock. Indeed no affected stock should be received. 
This, with other diseases, has been treated in Bulletins 
92 and 104. 
Frosty Mildew. Occassionally the frosty mildew fun- 
Fig. 69. Crown gall attack. 
ing stem of peach tree. 
gus (Cercosporella persica Sacc.) occurs, whitening over 
the under surface of the leaves. As yet it has not been 
a serious disease. 
