26 Maine; agricuIvTurai^ experime;nt station. 1909. 



fungus constantly associated with the disease. In fact dead 

 needles collected from the trees early in the season usually 

 showed no signs of fungi of any kind.* An opportunity came 

 to examine the roots of trees dug up out of an arbor vitse hedge 

 early in May. The hedge was apparently healthy in the fall 

 before but now the foliage appeared practically dead. The 

 roots appeared perfectly healthy when dug up and the leaves 

 showed no sign of fungi upon them. 



It seems to the writer only a logical inference to attribute 

 the injury above described to adverse weather conditions par- 

 ticularly when we summarize the observations. "Pine blight" 

 in 1907-1908 was coincident with the most destructive winter 

 injury of fruit trees in the history of Maine orcharding. A 

 similar trouble appeared to a greater or less extent on other 

 conifers. The disease which constituted the major part of 

 the trouble did not begin in particular centers and gradually 

 spread outward from them, but appeared simultaneously 

 in all parts of the State wherever the pine thrives. It did 

 not appear on the young needles during the summer but came on 

 suddenly in the early spring. Only the young and actively grow- 

 ing trees were badly attacked and these very much more 

 severely on the sides exposed to the prevailing cold dry winds 

 of winter. 



While it is possible for frost coming late in the spring to cause 

 the death of young needles, t it is very improbable that low tem- 

 peratures alone were responsible for the injury in this instance. 

 The fact that the injury recorded in 1908, the milder of the two 

 winters, was by far the most severe and widespread is entirely 

 against this interpretation. It is more probable that the trouble 

 may be accounted for as the result of excessive transpiration 



* Pine needles lying on the ground were usually quite thoroughly 

 infested with saprophytic fungi. Late in the season these fungi were 

 found in some cases to have spread to the dead needles still adhering 

 to the trees. Examination of needles on the same trees earlier in the 

 season failed to show any pustules on them and no mycelium within 

 the tissues, except in an occasional instance. Spots on the needles of 

 pines in the State due to fungus attacks can be found quite frequently 

 but these were by no means constantly associated with the trouble here 

 described. 



t Hartig, R. Text-book of the Diseases of Trees. English transla- 

 tion, by Somerville and Ward. p. iii (London, 1894). 



