8 BULLETIX 924. U. S. DEPARTMENT OE AGRICEXTrRE. 
Tasle IV. — Isolation of Colletotricham gloeosporioides, Cladosporium sp., and miscel- 
laneous organisms from orange and grapefruit rind affected with melanose or with 
'shark shin. 3 ' 
Variety. 
Remarks. 
Series A . diffused 
patches. 
Series B, tear- 
streak pattern. 
Series C. un- 
blemished. 
Lor and num- 
ber of fruits 
in group. 
.11 
£ 3 
c - 
3 "8 
7 5 
c 
m 
•s 
I 
on 
i 
g-s 
u o 
— o 
~ ft 
_. 
5i 
E '{■ 
e a 
— k 
0"So 
v. 
■J. 
& 
Xot disin- 
fected: 
Lot E, 4 
Grapefruit . 
do 
do 
do 
do 
Orange 
Grapefruit . 
do 
do 
do 
do 
do 
Orange 
Grapefruit . 
Melanose tear streaks . 
Bright area on mela- 
nose fruits. 
Melanose tear streaks . 
do 
Mud-caked melanose . 
Decided ' ' shark skin 
do 
Melanose tear streaks . 
40 
41 
51 
fruits. 
Do... 
07 
12 
23 
5 
40 
Lot G, 2 
fruits. 
Lot L, 2 
32 
31 
19 
17 
15 
C7 
11 
8 
11 
2 
45 
1 
15 
fruits. 
Lot X. 1 
fruit. 
Lot J. 4 
fruits. 
Lot K, 4 
fruits. 
Disinfected: 
Lot E, 4 
5 
1 
fruits. 
Do... 
Bright area on mela- 
nose fruits. 
Melanose tear streaks . 
do 
Mud-caked melanose , 
Decided ' -shark skin " 
do 
.; 
U 
. 5 
2 
.3 
Lot G, 2 
36 
5 
7 
2 
I 
2 
fruits. 
Lot L, 2 
S. 5 
C 
19 
2 
1 
1 
1 
3.5 
fruits. 
Lot X, 1 
fruit. 
Lot J. 4 
fruits. 
Lot K. 4 
fruits. 
It appears from. Table IV that 7ollefotriphum gloeosporioides is 
recovered with about the same frequency as is shown in Table III, 
thus indicating that no positive conclusion as to the causation of 
tear-stain can be reasonably based on isolation tests. 
All the cultural work shows that Collttolridnim gloeosporioides 
has an isolation percentage from tear-stained areas rather too low 
for it to be the active pathogen and that this organism is present 
to some extent on normal as well as badly russeted areas, the fre- 
quency varying with the degree of injury. 
The fungi in various types of miscellaneous lesions on citrus fruits 
were examined by similar cultural methods. These lesions included 
spray-burn scars, hail bruises, thorn scratches, and old citrus-scab 
lesions. The fungous flora was very similar to that obtained from 
tear-stained and russeted areas. Colonies of Colletotrichum pre- 
dominated, the saprophytic Cladosporium ranked next, while col- 
onies of bacteria and various other fungi occurred in smaller numbers. 
