278 Report of the Botanical Depaetment of the 



space between the bark and the wood, along the lower edge of the 

 callus, was filled with gum and the wood under the lower half of the 

 girdle was stained to the depth of perhaps a centimeter. The roots 

 of the tree appeared normal. 



A Geneva peach orchard. — In a young and bearing peach orchard 

 on the Experiment Station farm about 3 per ct. of the trees were 

 found to have patches of injured bark on their trunks just above the 

 ground. Three of the trees were completely girdled and more or 

 less enlarged above the wound, like the sour cherry tree discussed 

 above. But on most of the affected trees the dead areas of bark 

 reached less than half way round the trunks, and the trees continued 

 to look normal in 1911 and 1912. However, the foliage on the com- 

 pletely girdled ones had a yellowish tint in July and then some of it be- 

 came pmkish here and there. Figure A on Plate XVIII is an example 

 on which the enlargement was not very marked but where the dead 

 region was conspicuous on account of its being smaller than the trunk 

 above. Along the upper edge of the girdle the bark stood out from 

 the wood and the resulting cavity was filled with gum on July 5. 

 On other portions of the affected area the bark seemed only partially 

 loosened by the disorganization of the phloem, and no radial clefts 

 were present. The wood covered by the dead bark had become 

 stained to a depth of about 5 mm. 



The so-called bark-beetles (Scolytus) were boring into the bark 

 of the completely girdled trees. On the trunk, larger branches and 

 especially about the bases of small twigs the tiny cylindrical holes 

 of that insect were present in large numbers, but no borer holes were 

 seen on the normal nor on the slightly affected trees. 



During early July the stumps of several young peach trees Y\rhich 

 had been similarly affected by winter-injury and borers, were re- 

 ceived at the Experiment Station from different parts of western 

 New York. In most of these cases a rather conspicuous enlargement 

 or swelling occurred just above the dead girdle. No radial clefts 

 were found in the dead bark and the gum was present under the 

 raised portion of bark just below the callus. The phloem of the 

 dead bark had been disorganized as in the Geneva cases and on the 

 Sodus cherry tree, but the roots in all cases were normal as yet. 

 The cases of injury involving less than a complete girdle always 

 occurred on the northwest side of trunks in the Geneva orchard. 

 There is not very much wind protection, and the trees had been 

 growing uncommonly fast. 



During late August Cytospora pj^cnidia, apparently the imperfect 

 stage of Valsa leucostoma, were present in great numbers on the dead 

 bark that had been left on affected trees. But no example was seen 

 where the fungus had killed bark beyond the periphery of the orig- 

 inal injury, as bounded by callus along the margin of areas severely 

 affected very early in the vegetative season. 



