24 N. H. AGR. EXPERIMENT STATION. [Bulletin 157 



formed beneath the bark, but soon break through to the sur- 

 face, furnishing the most characteristic feature of the disease. 

 The stromata are firmly fastened to the wood by means of a hard 

 ring of fungous tissue, so that they remain attached to it even 

 after the bark has fallen away. Summer spores are produced 

 on the surface of the stroma. Later in the season, numerous 

 flask-shaped perithecia are formed within the stroma, but open- 

 ing on its surface. These produce many club-shaped asci, 

 each containing eight spherical, brown spores. 



Treatment. The fungus seems to be dependent upon wounds 

 for entrance to the host tissue. The best method of treatment 

 is found in avoiding unnecessary injuries to the tree and in the 

 proper care of all wounds. All cankered limbs should be 

 destroyed. 



WINTER INJURY. 



The A\dnter of 1906-1907 caused very serious injury in the 

 orchards of New Hampshire. The damage was especially great 

 in young orchards and in those situated on low ground. Many 

 trees were found to be entirely dead the next spring and others 

 had only sufficient vitality to put forth leaves on a few scattering 

 limbs. As the summer advanced it was evident that many trees 

 that had appeared fairly vigorous early in the spring had sus- 

 tained serious injury, and leaves on one large limb after another 

 would wither and turn brown. Thruout the summer of 1907, 

 and even in that of 1908, trees continued to succumb to the 

 injuries received in the above mentioned winter. 



Upon examination of the injured limbs and trees it was found 

 that the cambium and the inner bark had been dead over large 

 areas from the beginning of the season. Such injuries sometimes 

 amounted to practically a girdling of the limb or trunk and the 

 portions beyond were soon starved. In other cases, where the 

 girdling was not so complete, the tree survived for several months, 

 and in some cases seemed to outgrow the effects of the injury. 

 As the summer of 1907 advanced, sunken dead areas became 

 quite common on the injured but living trees. The living tissue 

 at the margin of these dead patches made a very unusual growth, 

 pushing out over the injury and developing a marked ridge 

 around it, thus leaving it as a conspicuously depressed area. 



