Nov. 15,1925 
Crown-gall Studies of Resistant Stocks for Prunus 
961 
and A. tangutica, appear to be more resistant, but so far only a 
single introduction has been tested by inoculation, and the inocula¬ 
tions of a larger number of seedlings may change their status in this 
respect. 
Table I. —Summary of artificial inoculations on species of Prunus and Amygdalus 
by cultures of Pseudomonas tumefaciens 
Species 
Common name 
Source a 
Number 
of inocu¬ 
lations 
Number 
of galls 
Per cent 
of infec¬ 
tion 
\. p.nmmnnis L 
Bitter almond_ 
NF_ 
190 
56 
29.4 
A. davidiana Zabel_ 
Davidiana peach (S. P. I. 
36664). 
S. P. I. 34601__ 
USDA— 
250 
130 
52.0 
A. mira (Koehne)_ 
A. pp.rsio,a. L 
USDA_ 
650 
120 
18.5 
Peach__ 
ESC. 
211 
187 
88.6 
A. persica _ _ __ 
Indian cling peach seed¬ 
lings. 
Peach (S. P. 1.40001). 
EST_ 
610 
396 
64.9 
A. persica__ 
USDA- 
250 
79 
31.6 
A. persioa pntanini Thicker 
Peach (S. P. I. 40009). 
USDA— 
200 
50 
25.0 
A. tangutica Korsh__ 
Chinese wild almond (S. 
USDA.... 
430 
25 
5.8 
P_ allp.ghfyniansis Porter 
P. 1.40010). 
Allegheny plum__ 
A A_ 
250 
12 
4.8 
P. andp.rsnni A. Gray 
Desert peach_ 
USDAF.. 
70 
30 
42.9 
P a/ngnst.i folia 1VT prsh 
Chickasaw plum_ 
ESC_ 
140 
37 
26.4 
P. angustifolia watsoni Waugh __ 
P. amp.rina.na Marsh 
Sand plum.. 
ESK_ 
180 
69 
38.3 
American plum_ 
A A_ 
180 
129 
71.6 
P. armeniaca L... 
Apricot (S* P. I. 32834)_ 
USDA.... 
60 
5 
8.3 
P. armp.nia.na.. 
Blenheim apricot_ 
NF... 
80 
76 
95.0 
P. armp.niana 
Royal apricot.. 
NF_ 
170 
140 
82.3 
P. armpniana.. 
Royal apricot seedlings— 
Tilton apricot_ 
ESC_ 
50 
39 
78.0 
P, armp.niana 
NF_ 
70 
52 
74.3 
P, armeniaca_ 
Apricot (S. P. I. 17154)_ 
USDA— 
140 
60 
42.8 
P« armeniaca mandshurica 
Maxim. 
P hp.ssp.yi Bailey 
AA.. 
170 
39 
22.9 
Bessey cherry__ 
NS.. 
280 
29 
10.4 
P, hp.ssp.yi Hybrid 
Sapa plnm ~_ n 
NS_ 
90 
54 
60.0 
P. besseyi Hybrid- 
Compass plum_J 
NS_ 
50 
12 
24.0 
P, caroliniana Ait 
Cherry-laurel... 
NP_ 
150 
0 
0.0 
P. cerasifera Ehrh__ _ __ _ 
Myrobalan plum ... 
NF, AA._ 
950 
725 
76.3 
P, np.ra.sifp.fa divarinata Railp.y 
A A _ 
100 
94 
94.0 
P. cerasifera pissardi Koehne_ 
Purple-leaf plum (seed¬ 
ling). 
Marianna_ 
ESC. 
50 
35 
70.0 
P t nprasifpra Hybrid 
NS_ 
90 
59 
65.6 
P. dasycarpa Ehrh 
Purple apricot_ 
A A_ 
210 
94 
44.8 
p domestics T, 
See Table II 
P. emarginata villosa Sudworth. 
P, fasniculata A. Gray. 
ESO_ 
40 
39 
97.5 
Desert almond__ 
ESC_ 
20 
4 
20.0 
P. fremonti S. Wats_ 
Desert apricot. 
USDAM _ 
90 
48 
53.3 
P. hortnlana "Bailey _ 
Hortulana plum.. 
AA .. 
130 
108 
83.1 
P. hortulana.. 
Golden Beauty plum. 
AA .. 
190 
51 
26.8 
P. ilinifnlia Walp 
Hollyleaf cherry.__ 
NF_ 
150 
0 
0.0 
P. insititia L_ _ - 
Shropshire plum__ 
NF_ 
230 
35 
15.2 
P. insititia_ _ _ 
St. Julian plum_1. 
NS. 
110 
11 
10.0 
P, lynni Sarg 
Catalina cherry.. 
NP_ 
80 
3 
3.7 
P r marit.ima Marsh 
Beach plum___ 
A A_ 
140 
48 
34.3 
P, mexinana S. Wats 
Big-tree plum_ 
USDAW _ 
280 
167 
59.6 
P. minrophylla Hemsl 
Mexican almond_ 
UCP.. 
60 
29 
48.3 
P. minutiflora Engelm ... 
Texas almond_ 
USDAH.. 
60 
30 
50.0 
P. munsoniana Wight and Hedr_ 
P, mnme Sieh. and Zuce. 
Wildgoose plnm _ _ 
AA.. 
160 
118 
73.7 
Japanese apricot.. 
USDA— 
4,950 
307 
6.0 
P nigra Ait 
Canada plum__ 
AA.. 
80 
76 
95.0 
P, orthosepala Knehne 
A A_ 
90 
80 
88.8 
P pumila L 
Sand cherry__ 
USDAW- 
450 
1 
0.2 
P sp.rot.ina Ehrh 
Black cherry ... 
AA. 
NB_ 
150 
24 
16.0 
P simoni Ga.rr 
Apricot plum... 
NF.. 
130 
130 
100.0 
P, spinosa L 
Blackthorn plum_ 
NF_ 
80 
57 
71.2 
P. siibnnrdata Benth. 
Sierra plum_ 
USDAF.. 
15 
3 
20.0 
P to rnAT, l ;nsa Thnnh 
Nankin cherry__ 
A A. 
25 
22 
88.0 
P. umbellata Ell_ . 
Black sloe (S.'P. I. 38974). 
USDA.... 
150 
1 
0.6 
P nmbellata 
Seedlings (S. P. I. 38974).. 
ESC_ 
690 
173 
25.0 
P nmbellata injnnnnnda. Sarg 
AA.. 
25 
22 
88.0 
° The explanation of the letters used in Tables I, II, and VIII may be found under “Source of Material.’ 
Prunus armeniaca has not thus far shown any marked resistance 
in any of the horticultural varieties tested. P. armeniaca mand- 
sJiurica y considered by some a distinct species, is somewhat resistant. 
