270 A NEW APPLE TREE CANKER. 



Inoculation of Leaves. — A shoot was atomized with a suspen- 

 sion of spores obtained in pure culture, and kept/ under moist 

 conditions in the greenhouse for about 48 hours. No effects 

 were visible after two weeks. 



Summary. 



In this paper a fungus belonging to the genus BotVyosphccria 

 is described, which is the cause of a rather serious canker of 

 a]:)])le trees at the Vereeniginy; Estates. 



An account is given of its mor])hology and its salient cul- 

 tural characters, and of a number of inoculation exj^eriments 

 Avhich were carried out with the fungus at the laboratories. 



The differences between the fimgus under discussion and 

 Phyalosporai cydoiiicc, the cause of New York apple tree canker, 

 are noted. The fungus shows some affinities with several other 

 s{)ecies of the genus, but is sufficiently different to be considered 

 a new species. Accordingly, the name of B. utali has been 

 assigned to this fungus. 



Reeerences. 



(1) Hesler, L. R. — "Black Rot, Leaf Sj-iot, and Canker of 



Pomaceous Fruits," Bull. 379 of the Cornell Agric. Ex- 

 ])eriment Station (1916). 



(2) (Jrossenbacher, J. G., and Duggar, B. M. — " Contri- 



bution to the Eife History, Parasitism and Biology 

 of Botryosplurria Ribis." New^ York Agricultural Ex- 

 periment Station, Technical Bulletin No. 18 (T911). 



(3) McAlpine, D. — " Fungous Diseases," p. 119, figs. 217-220. 



(4) Saccardo. — " Sylloge Fungorum," XL, p. 504. 



(5) Pieper, Humphrey and Aeree. — "Synthetic Culture Media 



for Wood-Destrcn-ing Fungus.'" Phyto])atliology. Vol. 

 \'II., p. 214. 



(6) Phytopathology. Vol. ML, loc. eil., 216. 



(7) Coons. G. H. — " Factors Livolved in the Growth and the 



Pycnidium Formation of Ple)wdoiiius fuscoinaculans." 

 — Journal of Agricultural Researcli, Vol. \\. ]). jit^. 



(8) Van der Bijl, P. — "A Study on the ' Dry Rot ' Disease of 



Maize." Union Department < f Agriculture. Sci. Bull- 

 No. 7. 



(9) Grossenbacher and Duggar — loc. cit. 



(10) Ridgwav — "Colour Standards and Nomenclature." PI. 



xiii. 



(11) Coons, loc. cit., \). 720. 



(12) Durand. — "The Differential Staining of Litercellular 



Mycelium." Phytopathology, Vol. I (1911). p. 129. 



