GROWN GALL ON MINNESOTA RASP- 

 BERRIES. 



The Minnesota law provides that the Nursery Inspector take 

 C(:>gnizance not only of "dangerously injurious insects" in nurseries, 

 but also of "contagious diseases." Crown Gall comes under the latter 

 head. 



This disease first attracted the attention of Experiment Station 

 workers in 1892 in California. It is n.ot our purpose to discuss "hairy 

 root"' which appears in, connection with Crown Gall on the apple, nor, 

 in fact, to touch upon the crown gall of the apple at all in this publi- 

 cation, beyond the statement tliat it is believed that apples infested 

 with this disease do not thrive, do not bear good crops, and may suc- 

 cumb. This is contradicted by at least one of our local nurserymen, 

 who claims that they do well in spite of its presence. It is possible 

 that the hard crown gall is confused with the so-called "soft gall" in 

 this connection. It might be said, however, that probably many a 

 plainer has accc])ted trees infested with "hairy root" (a disease in 

 which is produced a large number of black, wiry rootlets in connec- 

 tion Vv ith gall-like swellings ) not knowing, and the nurseryman selling 

 them to him not knowing that such trees will remain stunted, in spite 

 of the seemingly fine root growth. We propose to discuss here, very 

 briefly, the danger which threatens our raspberries, since it is of this 

 that complaints have been received. 



The crown gall found upon apples caimot, as far as is known, be 

 easily transmitted to raspberries, blackberries, plums, cherries, etc. It 

 is believed, also, that the raspberry and blackberry cannot readily 

 transmit their peculiar form of crown gall to the apple. We know of 

 one Alinnesota nurseryman who reared a good crop of apple roots on a 

 patch which had been plowed up three years before on account of 

 crown gall on raspberries. The "soft form" of crown gall on plum, 

 cherry, peach, raspberry and blackberry, is highly contagious (this has 

 been demonstrated in practice), and is evidently the same species on all 

 five of these latter fruits. I'lie most recent workers claim that this 

 form of crown gall is of bacterial origin. It would appear too, that 

 the reproductive form of the organism may remain alive on surface 



