KFFECT OF THE DISEASE ON APPLE TREES. Bul 
Garman (16), expresses an opinion to the effect that crown-gall 
trees can never be very profitable, since in their enfeebled condition 
they will not bear well. 
Alwood (2), who made an extensive study of this disease, in his 
introduction, referring to the results of his experiments, states that 
these results ‘“‘seem to point clearly to the conclusion that every 
planter must be prepared to detect this trouble, and exclude it from 
his orchard plantings.”’ Commenting further on the results of his 
experiments, Alwood says: ‘‘Our observations in more recently 
planted orchards show that it is not usual for trees showing an attack 
of this trouble to form a normal root system; the root development 
is weak and confined to the surface. * * * We are also of the 
opinion that badly diseased trees, such as are now very commonly 
found in nursery stock, will not ordinarily come into fruiting.” In 
a lecture before the Maryland State Horticultural Society Alwood (4) 
is quoted as saying, in speaking of orchard trees diseased with crown- 
gall, that ‘‘they have scarcely grown at all, although they have been 
cultivated for five years.” 
Butz (7), in speaking of eleven apple trees planted on the Pennsyl- 
vania Agricultural Experiment Station grounds, reports that after 
two years’ growth the trees showed “‘immediate injury, due to the 
galls.’ 
Norton (34) states that ‘‘trees affected with crown-gall set out in 
the college yard have never done well.” In a later publication (37) 
he makes the following statements: 
The galls, when they occur on the main root, may interfere with the transfer of the 
sap in the tree, and thus weaken it. The constriction by the gall may cause the tree 
to fruit too young, or to overbear; they cause abnormal root development, and thus 
hinder the growth. They are often so well developed as to cut off and cause the 
death of the taproot, which is almost always killed when affected throughout by the 
hairy-root condition. The tissue of the gall may decay and form an entrance for 
wood-rotting fungi which will soon destroy the tree. 
R. E. Smith (55) reports apple crown-gall to be very common in 
nurseries, but apparently it ‘‘does not result as seriously in orchard 
trees as with the similar disease on stone fruits.” 
Morris (33) makes the following assertion: ‘‘The trees affected 
with galls at the crown are doomed to death sooner or later. Some- 
times the trees are completely girdled and starved to death, at other 
times the root of the tree is so weakened that it is easily broken by 
wind.”’ 
Sandsten (48), concerning crown-gall, says: 
Some kinds of fruit trees are less resistant than others. For example, it is well 
known that a young peach tree infested with the disease will live for a relatively short 
time, while apple trees may live for a number of years * * *. Perhaps the chiet 
reason why fruit growers fear the disease is that just about the time when the trees 
186 . 
