270 
Journal of Agricultural Research 
Vol. IX, No. 8 
present in the orchards of the western parts of the State and to some 
extent in other parts. 
The same disease, no doubt, occurs in other States. Fulton and Crom¬ 
well 1 report its occurrence in Pennsylvania, and Fromme and Thomas 2 
have reported it from Virginia. 
LOSSES FROM ROOTROT 
No approximation has been made of the losses occasioned by this root- 
rot. Several very obvious reasons can be mentioned to show that the 
assemblage of such data is next to impossible. In the first place, the 
symptoms in the above-ground parts of affected trees, as will be made 
evident later in this report, are not sufficiently characteristic to separate 
this rootrot from other diseases in which the root system is impaired. 
In order, therefore, to be certain of a field diagnosis, it is necessary to 
remove the soil from the collar and roots of suspected trees. Owners of 
orchards are generally reluctant to have any considerable number of their 
declining trees disturbed in this manner. In one orchard, however, io 
unhealthy trees were examined in this manner, and 5 were found to be 
characteristically affected. The disease was found to be generally present 
on a few trees in the considerable number of other orchards which were 
examined. It can only be said with reference to losses from this root 
disease that a small number of trees each year succumb in every orchard 
in which this trouble is present. These trees range in age from 8 to 30 
years. 
APPEARANCE OF THE DISEASE 
As no part of the causal organism has been found to appear above the 
surface of the ground, there is no evidence of the presence of rootrot 
until after the disease has become well established and a considerable 
number of roots are involved in decay. At this stage the most prominent 
symptom among the above-ground organs is revealed by the foliage. If 
it is borne in mind that the destruction of roots proceeds gradually and 
that affected trees may live for several years, it will be realized that the 
symptoms change as the disease advances. The leaves on trees whose 
root systems are in intermediate stages of decay are generally quite 
normal in size, but are fewer in number than on healthy trees. In more 
advanced stages the leaves are sometimes as small as one-third the normal 
size. The progressive inability of diseased trees to store up sufficient 
reserve food very probably accounts for this production of undersized 
leaves. In addition, various degrees of chlorosis are always manifest. 
Certain abnormalities in fruit production commonly accompany the 
presence of abnormal foliage. The one most generally noted is the 
1 Fulton, H. R., and Cromwell, R. O. Loc. cit. 
a Fromme, F. D., and Thomas, H. E. The rootrot disease of the apple in Virginia. In Science, n. s- f 
v. 45.“0. 1152. P- 93 - 1917. 
