Feb. 15, 1925 
Inoculation of Coniferous Stems 
337 
Fusarium spp. 
The results of inoculation with 
various species of Fusarium are given in 
Table V. F. sporotrichioides and F. 
discolor sulphureum were very parasitic, 
comparing favorably in virulence with 
the more parasitic Pythium and Cor- 
ticium lines. The species of the moni- 
liform section of Fusarium ranged in 
virulence from the very parasitic to 
the almost nonparasitic forms. F. 
arthrosporioides , F. hyperoxysporum, F. 
trichothecioides, and Gibberella saubi- 
netii were all moderately parasitic. F. 
eumartii, F. oxysporum, and F. ventri- 
cosum were definitely nonparasitic under 
the conditions of these experiments. F. 
acuminatum , F. avenaceum. F. coeru- 
leum, certain lines of the F. discolor 
groups, F. martii, F. radicicola and F. 
Fusarium moniliforme caused 3 out of 
10 seedlings to damp-off. This purely 
preliminary experiment indicates F. 
caribaea as a new host for F. monili- 
forme. 
Botrytis spp. 
Table VI gives the results of inocu¬ 
lating Pinus resinosa and P. banksiana 
with Botrytis spp. The two available 
small sclerotial forms of Botrytis were 
either very slightly parasitic or en¬ 
tirely nonparasitic on both pine hosts. 
When grown on rice mush one of them 
seemed fairly parasitic to F. resinosa. 
It is probable, however, that this 
specialized parasite under ordinary 
conditions would be of no importance 
on coniferous seedlings. 
The large sclerotial forms of Botrytis 
were all much alike and were all of the 
Table VI.— Damping-off of coniferous stems caused by miscellaneous fungi 
Tested fungi 
Number of 
lines tested 
Number of seed¬ 
lings inoculated 
Per cent of seed¬ 
lings killed 
On Pinus resin¬ 
osa i 
On Pinus bank- j 
siana j 
Pinus 
resinosa 
Pinus banksiana 
Pinus 
resinosa 
Pinus banksiana 
j 
Average 
Average of cor¬ 
rected percent¬ 
ages. 
Agar in¬ 
oculum 
' Rice in¬ 
oculum 
Agar in¬ 
oculum 
Rice in¬ 
oculum j 
Botrytis cinerea: 
. All lines_ 
i 6 
4 
130 
130 
70 
68 
95 
94 
86 
86 
Lines isolated from coniferous hosts.. 
! i 
1 
20 
20 
20 
50 
90 
80 
73 
68 
Lines isolated from other hosts_ 
5 
3 
110 
110 
50 
72 
96 
100 
89 
92 
Phomopsis juniperovora _ 
4 
4 
70 
90 
80 
21 
53 
66 
47 
35 
Cephalothecium roseum _ 
1 
1 
20 
20 
20 
30 
45 
35 
37 
14 
Small sclerotial Botrytis _ 
2 
2 
40 
40 
40 
13 
32 
5 
17 
12 
Pestalozzia funerea? _ _ 
1 
1 
20 
20 
20 
0 
20 
0 
7 
7 
Verticillium sp_ :_ 
1 
1 
20 
20 
20 
0 
0 
0 
0 
0 
Thielavia basicola _ _ _ 
; i 
1 
10 
10 
20 
0 
i 0 
0 
0 
0 
Controls 
975 
1, 225 
450 
0.1 
2. 5 
0.7 
1 
f. 
vasinfectum were either nonparasitic or 
at times very doubtfully parasitic. It 
is not probable that any of these would 
cause much trouble under nursery con¬ 
ditions. Certain lines of the F. cul- 
morum group, F. martiella, Nectria 
ipomoeae, F. orthoceras , F. solani and 
some unidentified Fusarium spp. showed 
evidence at times of being intermediate 
between the very parasitic and the non¬ 
parasitic groups. Further experiments 
are absolutely necessary before the 
ability of either of these last two classes 
to attack conifers is established. 
In no case where there was a definite 
measurable degree of parasitism was 
Fusarium so active on corn-meal agar 
inoculum as on rice mush. (Table V 
and fig. 2.) In one small experiment 
with Pinus caribaea in which none of 
the 10 control seedlings died and in 
which 4 of the 10 seedlings inoculated 
with Pythium debaryanum damped-off, 
type which has previously gone under 
the name of Botrytis cinerea. It is con¬ 
sidered best to continue the use of that 
generally known name until there is 
published warrant for change or segre¬ 
gation. These large sclerotial forms 
were more parasitic than the standard 
Fusarium line. They were always as 
destructive, and in most cases more so, 
than the standard Corticium line, and 
in all but one experiment, fully equaled 
the standard Pythium debaryanum. It 
is a less important parasite for conif¬ 
erous seedlings than the latter, because 
in only a few cases has it been isolated 
from damped-off coniferous seedlings. 
A comparison of the damping-off 
caused by the same lines of Botrytis 
cinerea on Pinus resinosa and F. bank¬ 
siana, gave in both cases a result of 
94 per cent, both species appearing 
highly and equally susceptible to them. 
There is a slight difference between 
