86 U.S. DEPT. OF AGRICULTURE MISC. PUB. 939 



Mississippi River, with a few infections in Texas. A large part 

 of the persimmon range, such as the main Mississippi River 

 Delta, the Appalachian Mountain chain to Georgia and Alabama, 

 and the area north and west of North Carolina and Tennessee 

 has remained free of wilt so far as is known. The disease was 

 especially severe in the period 1930-50, and while occasional 

 cases are still reported in the eastern States, and there have been 

 recent outbreaks in Texas and Oklahoma, it appears much less 

 commonly now than in the 1930's and still has not invaded many 

 areas where persimmon abounds. 



Hosts: Ebenaceae — 



Diospyros virginiana L., very susceptible 



D. ebenaster Ratz, very susceptible 



D. texana Scheele, susceptible 



D. lotus L., resistant 



D. kaki L., resistant 



D. rosei Standley, immune 



D. mosieri Small, untested, but wilt-free in Florida, 



Literature : 



Crandall, Bowen S. Spread of persimmon wilt. Plant Dis. Rptr. 

 27:158-160. 1943. 



. A new species of Cephalosporium causing persimmon wilt. 



Mycologia 37 : 495-498. 1945. 



and Baker, W. L. The wilt disease of American persimmon 



caused by Cephalosporium diospyri. Phytopathology 40: 307- 

 325. 1950. 

 Toole, E. R., and Lightle, P. C. Status of persimmon wilt, 1959. 

 Plant Dis. Rptr. 44 : 45. 1960. 



Oak Wilt 



C. E. Seliskar 



Forest Service, U.S. Department of Agriculture, Delaware, Ohio 



Ceratocystis fagacearum (Bretz) Hunt. A vascular wilt disease of 

 oaks, known only in the eastern half of the United States. Symtoms 

 differ between species of the red oak group and those of the white oak 

 group. In red oaks, symptoms are characterized by a wilting and 

 bronzing of the foliage, starting at the top and tips of branches and 

 spreading rapidly throughout the entire crown. Individual leaves 

 bronze progressively from the tip to the base, oftentimes leaving a lo- 

 calized area of green tissue at the base around the midrib. Leaves in 

 all stages of discloroation, including green leaves, are shed more or 

 less continuously as the disease progresses. Bole sprouting is often 

 observed on wilting trees. 



Trees of all ages are affected and usually die the same season sym- 

 toms appear. Occasionally large trees, or trees affected late in the 

 season, survive until the following spring, but, invariably, all infected 

 red oaks die. White oaks are generally more resistant to the disease, 

 however, and may live several or more years before they die. In some 

 cases, infected white oaks recover; diseased trees showing no foliar 

 symptoms have been reported. Affected trees usually exhibit symp- 

 toms in one branch at one time as the disease slowly progresses through- 



