No. 601] RESIST ANCE OF PBUNUS TO CROWN GALL 



55 



6/13/13 



6/17/13 

 7/14/13 



7/21/13 

 7/30/13 



right angles to the twig which makes these galls stand out for 

 considerable distance from the branch. 



It is of interest to note that both of these are prunes that have 

 been under cultivation for many years. The German prune is 

 described as being one of the plums longest under cultivation and 

 the oldest of the prune type. Seedlings also come reasonably 

 true to type which might be of importance if grown from seed 

 for a stock. The Italian prune (Fellenberg) is the popular 

 prune of Oregon and has a history of over a century's cultiva- 

 tion. Further experiments among varieties of the domesHca 

 group are being carried on. The damson which is 

 included among the domesticas, shows considerable i 

 artificial inoculation. 



Primus cerasifera, var. Planteriensis, Table VIII, 

 as a double flowering shrub and is the most gall resistant of any 

 of the tested varieties of cerasifera, although this resistance 

 should be again determined. Inoculations in the Arnold Ar- 

 boretum trees, Table IV, did not develop as many galls as those 

 of the larger Myrobolan tree, either because the former were not 



* A local commercial stock, propagated in California from sprouts, not the 

 true Duane variety, but a small blue plum having the flavor of a Damson, 

 but differing in shape. 



