1068 
Gall Moth 
Gelechia pinifolia 
6. A gall making moth, similar to a 
“Clothes moth.” 
Gall Fungus 
7. Any fungus of the order Chytridia- 
ceae, that causes galls in plants, specific- 
ally, one producing a disease in cranber- 
ries and related plants. 
Gall Bacterium 
Bacterium tumefaciens 
8. A bacterium that seems to be al- 
ways present with crown gall and may 
infect healthy trees with the disease. 
Gall Worm 
9. The Nematode eel worm. It is not 
properly an insect but belongs to that 
class of animals known as Vermes. It 
attacks the potato more generally perhaps 
than any other field crop and this may 
be an objection urged against planting po- 
Crown Gall on Roots of Apple Trees. 
Nre.. 25 
tatoes among orchard trees, unless under 
conditions where the freezing of winter 
would kill the worms. 
Forms of Crown Gall 
*Hedgecock says that the _ different 
forms of gall, such as “hard gall,” “soft 
*Bureau of Plant Industry, Bulletin 186. 
ENCYCLOPEDIA OF PRACTICAL HORTICULTURE 
gall,” and various other forms and var- 
ieties of the disease such as are found on 
raspberries, blackberries, the peach, ap- 
ple, etc., also the hairy root galls, are 
but varying forms of the same disease. 
Though the disease varies in the different 
plants and different stages of develop- 
ment, yet in all cases it is the same in 
character, produced by the same causes 
and always somewhat contagious. Hence 
in no case should shrubs bearing this 
crown gall be allowed to go into the 
trade. Like nearly all bacterial contag- 
ious affections, the only safe way to treat 
it is to absolutely bar its entrance. 
Eeonomic Effects of Crown Gall 
7yStewart says that “Crown Gall, Bac- 
terium tumefaciens, in New York is com- 
mon on apple trees as well as on several 
other woody plants. During 12 years of 
experience he has never known of a well 
authenticated case in which crown gall 
has seriously affected apple trees in the 
orchard.” In 1899, C. H. Stewart & Co., 
of Newark, N. J., set out an experimental 
orchard of 500 trees, mostly Baldwins, all 
affected with crown gall. The trees have 
now been set nine years, and show as 
good growth as the trees planted at the 
same time and free from crown gall. 
The bark is smooth, healthy in appear- 
ance and the trees look thrifty and vig- 
orous. 
“In 1901, we planted 22 apple trees af- 
fected with crown gall to determine the 
effect of this disease upon the growth of 
the trees. The trees were three years 
old. The galls varied in size from one 
to two inches in diameter, and were lo- 
cated mostly on the tap root, but in a 
few cases on the lateral roots. Some of 
the trees had several galls each. We be- 
lieve the galls were typical of those found 
on the trees of New York nurseries. Five 
of the trees were dug up in 1903, five in 
1905, and five in 1907. In no instance 
was there any evidence that the galls had 
increased in size or number or that they 
had been in any way injurious to the 
trees. Probably apple trees bearing large 
galls should be rejected, but unaffected 
+ New York (Geneva) Experiment. Station, 
Bulletin 328. 
