Winter Meetincj. 253 



the peach, is very soft, and easily cut with a knife. As it grows 

 older, it may form abnormal tissues in the center. Experiments 

 with this type of apple gall indicate that while it can be grafted 

 readily, it is not infections to any degree, if at all. Results from 

 cross inoculations with the galls of the peach and other stone fruits 

 indicate that this form may be similar, but is not infectious on the 

 apple tree, like that of the peach and other stone fruits. The 

 amount of soft gall found in nursery stock as it comes from the 

 field ungraded is very small — probably not over 1 to 5 per cent. 

 The hard form, on the other hand, is quite common. Often as high 

 as 50 per cent, of the trees of some varieties may be affected with 

 this type. Trees affected with the soft crown-gall are apt to be 

 stunted, and this disease is thought to be quite injurious to the 

 tree. Owing to the inf requency of the disease and the small chance 

 of infection, it is not to be classed with the crown-gall of the peach. 

 There is no indication that this disease will spread from tree to tree 

 in the apple orchard. 



The hairy-root disease of the apple tree is more common than 

 either the hard or soft crown-gall on some varieties. One form of 

 the disease is prevalent on seedlings, and may be easily distin- 

 guished by numerous fibrous roots on a short, stunted tap root. 

 Such seedlings should be rejected. Another type takes the form 

 of a bunch or mass of soft, fleshy roots, which usually spring from 

 a bud on the scion. This type may spring either direct from the 

 root or may originate in a cushion of callous-like tissue, much 

 resembling the hard crown-gall. In the latter case, however, the 

 roots do not spring directly from the callus, which appears to be of 

 a secondary nature. A third type consists of a bushy outgrowth of 

 much branched, fine roots, either direct from the main root or wood 

 of the tree, or from a side root. There is no proof that any of these 

 forms are infectious or contagious. The first apparently interferes 

 with the growth of the tree, but the two latter have little effect upon 

 it. These latter, however, are apparently connected together with 

 the scion, and experim^ents indicate that careful selection of scions 

 from trees which are free from these troubles will soon eliminate 

 this form of root. This type of root should not be confused with 

 the ordinary fibrous rooted tree, which is common in many nur- 

 series, and orchardists need not fear to set out this type of tree nor 

 those of the former type where the trees have every indication of 

 making a vigorous growth, unless the root system should consist en- 

 tirely of fine roots. In the latter case it would be best not to plant 

 them. 



