DEATH OF CHESTNUTS AND OAKS. 7 



AREAS INFECTED BY ARMILLARIA MELLEA. 



Ten distinct badly diseased areas of varying sizes were found in 

 which the Armillaria root-rot had killed many trees. On one area 

 40 yards in diameter, both chestnuts and oaks of large size had been 

 killed, including 6 chestnuts with diameters of 8, 8, 10, 12, 14, and 

 16 inches, and 4 oaks with diameters of 8, 13, 14, and 14 inches, re- 

 spectively. Another rather large area had 34 dead trees scattered over 

 it; of these there were 25 white oaks, 6 chestnuts, and 3 poplars. 

 These trees ranged from 3 inches to 26 inches in diameter. On none 

 of these diseased areas were all of the trees killed; some were alive 

 and apparently in good health. This root-rot apparently was much 

 worse where the soil was very damp, or even wet, during certain 

 portions of the year. 



Mr. H. M. Sears, of the Forest Service, in a report entitled "Deteri- 

 oration of Blight-Killed Chestnut in Northern New Jersey," mentions 

 the presence of the rhizomorphs of Armillaria mellea beneath the 

 bark of some of the dead chestnut trees. No evidence was advanced, 

 however, to show that this fungus had attacked the chestnut trees 

 before they died. 



ARMILLARIA MELLEA ON CHESTNUTS IN NORTH CAROLINA. 



AREA EXAMINED. 



On a recent trip through North Carolina, the writer found a rhizo- 

 morphic root-rot prevalent on the chestnut near Mount Airy, N. C, 

 which is apparently the same as that found in New York. As the 

 investigations in North Carolina were devoted primarily to the heart- 

 rots of trees, very little time was given to this root-rot problem. 

 However, some data on the character and extent of the disease were 

 taken. The area studied was located about 6 miles east of Mount 

 Airy, near Brim, N. C. 



CHARACTER AND GENERAL CONDITION OF THE TIMBER. 



The timber was located on the ridges and slopes and consisted of 

 a mixed stand of chestnut and oak growing in a rather thin, more or 

 less rocky soil with a red-clay subsoil. Chestnut oak (Quercus prinus) 

 was the principal species of oak, but white oak (Q. alba), black oak 

 (Q. velutina), and red oak (Q. rubra) were also present. All of the 

 chestnut over the area examined was deteriorating, 90 per cent was 

 stag headed and much was actually dying, while from 20 to 30 per 

 cent was already dead. There was little or no sprout reproduction 

 from the bases of the affected trees. Because of the rotted condition 

 of the roots, the dead and dying trees in this region are easily blown 

 down. According to resident millmen, this dying of the chestnut has 

 become very pronounced during the last fifteen to twenty years. 



