234 The Connecticut Pomological Society 



cides, and extremely contagious. Professor Tourney, formerly 

 of the Arizona Experiment Station, has recently made a careful 

 and thorough study of the disease as it occurs on almond trees. 

 He has shown that it is caused by a minute organism, occur- 

 ring in the soil and related to that which causes the familiar 

 "club-root" of turnips and allied plants. He has furthermore 

 proved that it can be transferred to a healthy tree from bits of 



Fig. I. SOOTY SPOT OF APPLE 



the galls remaining in the soil from which a diseased tree has 

 been removed, so that in case a diseased tree is dug up care- 

 lessly the disease is certain to be spread broadcast when the 

 plow, harrow, or cultivator is run over the spot. The greatest 

 care should therefore be exercised in digging up such a tree 

 not to break off any of the galls; the tree should be burned 

 at once and upon the very spot whence it came. Of course 

 all nursery stock showing the crown -gall should be destroyed 

 by fire. 



The disease can be kept in check by examining the trees 

 once a year, cutting off the galls, and covering the wound with 



