4 A. L. PlERSTORFF 



ash (Sorbus aucuparia var. laciniata Beissn.) is a menace to the fruit 

 grower. Snow (1922) does not include mountain ash among the list 

 of proved suscepts, and the writer has been unable to find in the 

 literature any reports of inoculations or cultural work which would 

 substantiate the common belief that this plant is susceptible. 



Arthur (1885 a: 362) proved by inoculation experiments that the fire- 

 blight organism may attack June berry (Amelanchier canadensis (L.) 

 Medic), English hawthorn (Crataegus oxyacantha L.), and an ever- 

 green thorn (Pyracantha coccinea Roem.), and later (1887) b) he added 

 wild crab (Pyrus coronaria L.). Craig (1897") reported Crataegus 

 oxyacantha as a host for fire blight at Ottawa. Later, Edwards (1907), 

 in Ontario, reported that on C. oxyacantha var. splendens Schneid. the 

 disease is common. Waters (1921) isolated the causal organism from 

 English hawthorn in New Zealand, and added medlar (Mespilus ger- 

 manica L.) to the list. Reed (1914) says that blight was particularly 

 severe on Crataegus crus-galli L. in Missouri in 1913. Jones and Morse 

 (1903) proved that the Cheney plum (Prunus nigra Ait. 3 ) is attacked 

 by blight. Jackson (1915) added the Italian prune (Prunus domestica 

 L.). Snow (1922) gave cultural evidence that Prunus triloba Lindl. 4 is 

 attacked by B. amylovorus. The organism isolated was pathogenic to 

 green pear fruits immediately after isolation, but plum shoots inoculated 

 with it failed to exhibit symptoms of disease. Waite (1907) reported 

 that "the evergreen Eriobotrys Japonica is attacked by this disease very 

 commonly in Florida and Georgia, and recently has been found affected 

 in California." Speaking of the Christmas berry, Heteromeles arbuti- 

 folia Roem., he stated: "In March, 1906, I found a striking specimen, 

 badly attacked, at Vacaville. It had been affected on the blossoms the 

 summer before and several of the twigs contained the living bacilli, they 

 having been carried over the winter. It has since been found at Colusa 

 and several other points in California." Martin (1921) reported suc- 

 cessful inoculations on the loquat tree (Eriobotrya japonica). 



After isolating the organism and making cross inoculations, Paddock 

 (1903: 8) concludes: "The results of these experiments prove that pear 

 blight may attack apricot twigs and fruit and observations show that the 

 disease may do a considerable amount of damage. . . . Blighted twigs 

 were also found on Prunus simonii trees which were also thought to be 

 caused by an attack of pear blight." In 1915, Hotson found Royal Ann 

 cherries which were infected by the blight pathogene. Isolation of the 

 causal organism and reinoculation into green cherries caused the fruits 

 to blight. In the same year Hotson reported the yakimine also as 

 affected by blight, and the following year he published a photograph 



* P. americana var. nigra Waugh. 

 4 P. triloba var. plena Lindl. 



