16 CIRCULAR XO. 129, BUREAU OF PLANT INDUSTRY. 



for the other. Tliis might indicate that iiii(k>r ordinary contUtions 

 the wliite-pine bhster rust ^\^ll infect Ribes for a distance of about 

 10 yards from a diseased pine tree. But how far a really hard wind 

 or a small whirlwind may carry these spores is entirely unknown. 

 It should be mentioned that in the vicinity of Geneva, X. Y., in 

 1912, the uredospores of Cronartium rihicola were apparently blown 

 a distance of nearly half a mile, as some of the diseased Ribes were 

 that distance from other known diseased Ribes. ^ 



HOW THE FUNGUS IS CARRIED FROM ONE PLACE TO ANOTHER. 



It has been generally supposed that the wliite-pine ])lister rust 

 is carried from one locality to another onlj^ by means of infected 

 white-pine trees. Tliis is undoubtedly the way the disease reaches 

 new localities in the majority of cases. European writers ^ have 

 mentioned this as if it were the only means of transference of the 

 cUsease and some even state that Ribes bushes, which were diseased 

 one year did not show the disease the next year.^ So far as we can 

 find, few European wiiters have seriously considered that the fungus 

 might be carried considerable distances except by m-eans of diseased 

 young pine trees, although some ^ have noted the absence of pines 

 from the neighborhood of diseased Ribes bushes. 



The experience in this country, however, seems to indicate that the 

 fungus may be occasionally carried on dormant Ribes stock, and this 

 possibility was suggested by Stewart in 1906 ^ and by the writer m 

 1911." Occurrences of the disease upon Ribes where its origin could 

 not be traced to diseased pines led to this assumption as a possible 

 explanation of its otherwise inexplicable presence. 



1 Stewart, F. C, and Rankin, W. H. Cronartium ribicola and the proscription of Ribes nigrum. (Ab- 

 stract.) Phytopathology, v. 3, no. 1, p. 73, 1913. 



2 Tubeuf, Carlvon. 



(a) \'emichtnng des Weymouthskiefemrostes. Praktisehe Blatter fiir Pflanzenschutz, Jahrg. 1, Heft 

 8, p. 63, 1898. 



(6) Ueber die Verbreitung von Baumkrankheiten beim Pflanzenhandel. Mitteilungen, Deutsche 

 Dendrologische Gesellschaft, p. 15&-163, 6 fig., 1904. 

 Klebahn, Heinrich. Die Wirt wee hselnden Rostpilze. Berlin, 1904, p. 382-387. 



3 Hennings, P. Ueber das epidemisehe Auftreten von Cronartium ribicola Dietr. im Dahlemer botan. 

 Garten. Notizblatt, Konigl. Botanischen Garten und Museum, Berlin, Bd. 3, no. 28, p. 172-175, 1902. 



Fischer, Ed. Beitrage zur Kenntniss der schweizerischen Rostpilze. Bulletin de 1' Herbier Boissier, 

 t. 6, no. 1, p. 1(1-17, 1898. 



Jaczewski, A. A. Ezhegodnik sviedienil o boliezniakh i po^Tezhdeniiakh kul'tumykh i dikorastiish- 

 chikh polcznykh rastenil. God. 3, p. 142-143, 1908. 



4 Klebahu, Ileinrich. Die Wirtwechsehiden Rostpilze. Berlin, 1904, p. 3S2-387. 



Bondartseva, A. S. Rastitornye parazity kul'lurnykh i dikorastushchikh rastenil sobrannye v Kurskol 

 gubernii lietom 19(11, 1903-1905 godov. (L&s parasites v6getaux des plantes cultivees et sauvages, recueilUs 

 dans le gouverncment de Koursk en 1901, 1903-1905.) Acta Horti Petropolitani, t. 26, p. 19, 1906. 



Iwanoff, K. S. Die im Sommer 1898 bei Petersburg (Russland) beobaohteten Krankheiten. Zeitschrift 

 fur Pflanzenkrankheiten^ Bd. 10, Heft 2, p. 99, 1900. 



Hennings, P. Loc. cit. 



'•> Stewart, F. C. An outbreak of the European currant rust (Cronartium ribicola Dictr.). New York 

 State Agricultural Experiment Station, Technical Bulletin 2, p. 61-74, 3 pi., 1906. 



6 Spaulding, Perlcy. Notes upon Cronartium ribicola. Scienoe, n. s., v. 35, no. 891, p. 146-147, 1912., 

 |('ir. 12!) J 



