CEPHALOSPORIUM WILT OF ELMS 3 



England, as are the familiar white church spires which dot the countryside. 

 The elms not only are a cherisheJ heritage, but also possess a unique beauty 

 which, in the eyes of many, transcends that of any other tree. Moreover, the 

 charm of Massachusetts' elm-planted villages is one of their greatest commercial 

 assets. This has not long been recognized, but is becoming increasingly appre- 

 ciated as tourist, recreation, and leisure-time activities increase. Since the 

 Dutch elm disease (19)^ first threatened the elms in America it has become more 

 apparent that all diseases of elm, as well as of other shade trees, deserve much 

 careful study. 



REVIEW OF LITERATURE 



The genus Cephalosporium does not figure prominently in phytopathological 

 literature, but several species have been reported as occurring saprophytically. 

 Adams and Manns (2) reported C. sacchari Adams & Manns, as following corn 

 ear worm in the kernel rot of corn. Young (27) describes C. acremonium Corda, 

 in connection with callosities on garden truck. Abbott (1) attributes a leaf spot 

 of coffee to Cephalosporium sp. Corda, but considers it of minor importance. 

 In England, C. malorum K. and Beaum. was described by Kidd and Beaumont 

 (15) as the cause of rot on apples in cold storage. Another species, C. carpoginum 

 Ruehle, was found on apple fruit in the United States by Ruehle (24). Morrow 

 (20) claims that C. curtipes Sacc. is very common in forest soils, and Paine (22) 

 finds that members of the genus act as cellulose destroyers. Miiller (21) in 1933 

 reported C. lecanii Zimm. on scale insects of Citrus in Brazil, and suggested its 

 cultivation as an insect control measure. 



So far as the writers can learn, the only reports of any species of the genus 

 Cephalosporium occurring as an important plant parasite are in association 

 with the wilt or die-back of elm and with a canker of balsam fir. The latter was 

 reported by Christensen (8) as a serious disease in Minnesota and Wisconsin. 



The elm wilt disease was discovered rather recently and the literature concern- 

 ing it is very limited. In 1931 May (17) described a new elm disease which he 

 attributed to infection by the fungus Cephalosporium sp. Of 300 elm specimens 

 received by him during the previous year 10 percent were infected with this 

 fungus. He described the symptoms as very similar to those of the diseases 

 caused by species of Graphium and Verticillium. The cultures which he obtained 

 were white, cottony colonies of aerial mycelium, which later became light brown. 

 Spores, usually with one or two oil drops, were hj'aline, generally elliptic, variable 

 in shape, and averaged 1.9 by 4.5 microns in size. His specimens had been col- 

 lected from Iowa, Missouri, New York, Ohio, and Washington, D. C. 



Liming (16) found that the trees infected with Cephalosporium sp. showed 

 an increase in the diseased condition in the second year. He also stated that out 

 of 1407 trees suspected of the Dutch elm disease, 336 showed a fungus referred 

 to the genus Cephalosporium. 



In 1934, Goss and Frink (11) published an account of their studies of the 

 disease, which they found to be common in the city of Lincoln, Nebraska. They 

 inoculated both U. americana and U. pumila L. but inoculations were not 

 successful in the latter elm. In the former elm, the organism progressed more 

 rapidly upward than toward the root. Greater success was obtained in their 

 experiments when inoculating into roots and trunks, than when inoculating soil 

 or leaves. 



^Figures in parentheses refer to Literature Cited, page 23. 



