24 
BULLETIN L118, U. S. DEPARTMENT OE .UiKK'lLTURE. 
Table 6 gives the results of artifical inoculations of fruits of grape- 
fruit, Satsuma orange, and Dancy tangerine with the citrus-scab 
fungus, and Table 7 gives similar results on leaves of a number of 
susceptible species. Numerous inoculations were attempted on 
sweet oranges, but without exception they gave negative results. 
Because of space limitation these tests are not here reported in 
detail. 
Table 6. — Results of inoculations ivith the scab fungus on grapefruit, Satsuma orange, 
and Dancy tangerine fruits. 
Size of 
Date. 
fruit 
(in six- 
teenths 
of an 
inch). 
Total 
inocu- 
lations. 
Drop- 
ped or 
lost. 
Fruits 
remain- 
ing. 
Total 
posi- 
tive. 
Total 
nega- 
tive. 
Per- 
centage 
posi- 
tive. 
Degrees of infection. 
Grapefruit: 
Apr. 17, 1917... 
4 
6 

6 
6 

100 
Very severe. 
Apr. 10,1920.... 
4 
58 
9 
49 
48 
1 
98 
Do. 
4 to 5 
4 to 8 
31 
230 
6 
65 
25 
165 
23 
129 
2 
36 
92 
78 
Do! 
Apr. 19, 1920.... 
Do. 
Do 
4 to 8 
46 
9 
37 
4 
33 
10. 8 
33 Royal, no scab: 4 Fos- 
ter, 'badly scabbed. 
Apr. 20, 1917.... 
4 to 12 
16 
6 
10 
5 
5 
50 
Verv severe on small 
fruits. 
May 2, 1917 
2 to 20 
20 
1 
19 
11 
8 
58 
Infection mostly on small- 
est fruits. 
May 9, 1917 
4 to 20 
16 
2 
14 
11 
3 
79 
Do. 
Apr. 23, 1920.... 
5 
50 
20 
30 
29 
1 
97 
Moderate. 
May 27. 1920.... 
6 to 8 
36 
22 
14 
13 
1 
93 
Severe. 
Apr. 3. 1919 
6 
102 
49 
53 
53 

100 
Do. 
Apr. 20, 1918.... 
6 to 8 
38 
9 
29 
23 
6 
79 
Severe on smallest; mod- 
erate on larger fruits. 
Apr. 10, 1919.... 
6 to 8 
100 
33 
67 
67 

100 
Moderate. 
May 27, 1920.... 
6 to 8 
36 
22 
14 
13 
1 
93 
Do. 
Apr. 27. 1920.... 
6 to 8 
36 
22 
14 
13 
1 
93 
Do. 
June 4, 1920 
6 to 12 
40 
1 
39 
9 
30 
23 
Lesions on smaller fruit 
only. 
June 11, 1920... 
4 to 12 
25 
6 
19 
2 
17 
10.5 
Yellow, poor specimens. 
May 1.1917 
8 
25 
2 
23 
17 
6 
7-4 
Only a few lesions on 
each fruit. 
May 13,1920.... 
8 
24 
5 
19 
19 

100 
Very severe: Hall (Sil- 
ver Cluster). 
Apr. 17, 1919.... 
8 to 10 
108 
32 
76 
34 
42 
45 
Infection on smallest 
fruits only. 
Apr. 15, 1918. . . . 
8 
30 
10 
20 
15 
5 
75 
Moderate. 
June 17, 1920... 
14tol6 
15 
5 
10 

10 

Do 
10 to 24 
50 
20 
30 

30 

Apr. 24, 1919.... 
Mav 1,1919 
lltoH 
100 
29 
71 

71 

11 to 17 
99 
41 
58 

58 

Apr. 29, 1920.... 
12 
48 
19 
29 
6 
23 
21 
One or two small spots 
on each fruit: Hall 
variety. 
June 11,1920... 
12 
21 
5 
16 

16 

May 13,1920.... 
12 
14 
6 
8 
1 
7 
12.5 
Lesions very small; only 
one or two per fruit. 
Mav 8, 1920 
15 to 18 
50 
15 
35 

35 

May 13,1920.... 
16 
12 
6 
6 

6 

May 8, 9, 1919. . . 
lt0 22 
100 
32 
68 

68 

Mav 13,1920.... 
1 to 18 
7 
1 
6 

6 

May 15, 1919.... 
lto24 
100 
9 
91 

91 

Satsuma orange: 
May 24, 1917.... 
4 to 8 
328 
157 
171 
147 
24 
86 
Very severe. 
May 8, 1920 
5 
17 
3 
14 
14 

100 
Severe. 
May 31, 1917.... 
10 to 20 
100 
50 
50 
3 
47 
6 
Moderate on smallest 
fruits. 
June 4, 1920 
6 to 8 
18 
10 
8 
7 
1 
88 
Severe. 
May 27, 1920.... 
8 
5 
1 
4 
4 

100 
Do. 
June 11, 1920... 
8 
5 
2 
3 

3 

Do 
8 
4 
3 
1 

1 

June 25, 1920... 
12 
10 
2 
8 

8 

June 17, 1920... 
14 
10 
6 
4 

4 

June 25, 1920.. . 
16 
10 
1 
9 

9 

DaDcy tangerine: 
June 4, 1920 
4 
24 
7 
17 
13 
4 
76 
Verv severe. 
June 11, 1920... 
6 
20 
15 
5 
5 

100 
June 17, 1920.. . 
6 
25 
14 
11 
11 

100 
Do! 
June 25, 1920... 
6 
10 
2 
8 
8 

100 
Do. 
Do 
6 to 8 
10 

10 
9 
1 
90 
Do. 
