DANGEROUS INTERNATIONAL FOREST TREE DISEASES 85 



Hosts: Pinaceae — 



Pinus albicaulis Engelm. 



P. contort a Dougl. 



P. jeffreyi Grev. and Balf. 



P. monticola Dougl. 



P. ponderosa Laws. 



P. taeda L. 



P. virginiana Mill. 

 Literature : 

 Lohman, M. L., and Cash, E. K. Atropellis species from pine can- 

 kers in the United States. Jour. Wash. Acad. Sci. 30 : 255-262. 



1940. 

 Weir, J. R. Cenangium piniphilum N. sp., An undescribed canker 



forming fungus on Pinus ponderosa and P. contorta. Phyto- 

 pathology 11 : 294-296. 1921. 

 Weiss, F., and O'Brien, M. J. Pinaceae. In Index of plant diseases 



in the United States. Spec. Pub. 1, Pt. V: 827-850. U.S. Dept. 



Agr. Plant Dis. Surv. 1953. 



Persimmon Wilt 



G. H. Hepting 



Forest Service, U.S. Department of Agriculture 

 Asheville, North Carolina 



Cephalcsvorium diospyri Crandall. A vascular wilt of the genus 

 Diospyros (mainly D. virginiana L.) in the United States. Symptoms 

 are general wilting of the foliage followed by defoliation, brownish- 

 black vertical streaking deeply through the sapwood of the trunk and 

 branches, death of the tree within few months of first external symp- 

 toms, extensive fruiting of fungus as reddish blisters under firm bark 

 or as large reddish powdery areas composed of enormous numbers of 

 conidia exposed at the cambial region by exfoliating bark of recently 

 killed trees. The most important features in diagnosis are sudden 

 wilt; premature discoloration of foliage; heavy defoliation; streaking 

 of wood not only in last annual ring but often through 10 or more 

 rings of sapwood; simple isolation in agar culture, using sapwood 

 chips, of Cephalosporium diospyri as described by Crandall (1945) ; 

 powdery reddish spore masses in bark blisters or in masses under loose 

 bark. C. diospyri differs from most other described members of the 

 genus in its abundant production of orange-pink spores and in having 

 a faint pink color in culture. 



The causal fungus enters the vascular system through wounds, many 

 of which are insect-caused. Spring infection results in rapid develop- 

 ment of fungus through the vascular system, resulting in production of 

 dark gums that produce the wood streaks, tyloses, and vessel plugging. 

 Death commonly follows in 2 to 3 months, with sporulation usually 

 following immediately, from August to late autumn. 



Range: This disease killed on a catastrophic scale in central Tennessee 

 and little persimmon remains in that area. It has also caused 

 varying losses in an area embraced by the northern boundaries of 

 Xorth Carolina and Tennessee southward to the Gulf of Mexico, 

 extending through the north half of Florida, and west to the 



