Apr, 21,192^ 
Gummosis of Citrus 
217 
Tabl^ XIII .—Inoculations with pure cultures of Botrytis cinerea^ on i8-year-old lemon 
trunks except where noted 
Ex- 
peri- 
ment. 
No. 
Date of inocula¬ 
tion. 
Host. 
Gum- 
ming.i 
Botrytis 
fruiting.! 
Cracked 
outer 
bark 
area.! 
Date of examina¬ 
tion. 
Area killed, 
outer bark. 
Cm. 
I 
July 12,1912 
Lemon 
X 
X 
X 
July 28,1913 
32 by 8 
2 
.do. 
.. .do.. . 
X 
0 
X 
Mar. 9,1916 
30 by 8 
3 
Aug, 23,1912 
.. .do... . 
X 
X 
X 
.do. 
30 by 8 
4 
Dec. 23,1912 
...do- 
X 
X 
X 
.do...%.... 
10 by 8 
5 
Feb. 20,1913 
...do_ 
X 
X 
X 
6 
Mar. 14,1913 
...do_ 
X 
X 
X 
Sept. 3,1914 
20 by 5 
7 
July 13,1913 
...do- 
X 
0 
X 
Apr. 7,1914 
Very small. 
8 
.do. 
X 
0 
X 
9 
.do. 
Orange . 
0 
0 
0 
Feb. 6,1915 
No effect. 
10 
Lemon.. 
X 
X 
Apr. 2,1914 
Very small. 
II 
.do........ 
...do.... 
X 
X 
.do. 
Do. 
12 
.do. 
...do.... 
X 
X 
.do. 
Do. 
12 
.do. 
do.... 
X 
X 
.do.. 
Do. 
Control cuts for each 
. experi- 
ment. 
0 
0 
0 
^ x*»p<»itive; o«» negative. 
With most of these inoculations made on old lemon tree trunks such 
effects as the softening and death of the bark through to the wood in the 
earlier stages, the appearance of fruiting bodies, formation of gum, and 
the subsequent development of an area of dead outer bark surrounding the 
initially invaded area and finally of an outer noninvaded gummous zone 
were found to be identical with those of cases of the disease occurring 
naturally. 
Further inoculations into cuts on young bark of several species of 
Citrus and of deciduous trees are reported in Table XIV. 
Table XIV .—Inoculations with spores and mycelium from pure cultures of Botrytis 
cinerea on young trees of Citrus, and other hosts 
I. INOCULATED JULY 2, I913; EXAMINED AUGUST II, 1913 
Experi¬ 
ment 
No. 
Host. 
I 
Valencia orange... 
2 
Sour orange. 
3 
Lemon.... 
4. 
.do. 
C 
.do. 
0 
6 
Almond. 
Kind of tissue. 
Young branch. 
Small branch. 
Hardened bark. 
Young twig. 
Same as above without 
inoculum. 
Stem of young tree.... 
7 
Peach 
do 
8 
Plum (Burbank) 
do 
9 
10 
Pear... 
-do 
_do... 
Same as above without 
inoculum. 
Results. 
Gumming slightly. 
Healing without gumming. 
Cut filled with gum and healing 
back of it. 
Gum more copious than last; 
not healing. 
Healing without gumming. 
Gumming with small portion 
of bark killed at cut, then 
healed.' 
Much gumming. Killed slight¬ 
ly on each side of cut. Bark 
area 6 cm. long in wood. 
Gumming at first and then 
healing. 
Healed with enlarged scar. 
Healing perfectly. 
