19171 DISEASES OF PLANTS. 649 



For the prevention of the disease the planting of hardy varieties, the adoption 

 of methods that will reduce the moth borer, and the grinding of cane before it 

 is overripe are recommended. Two related fungi, M. saccharinum and M. iliau, 

 both of which have been reported as attacking cane, are not considered as 

 causing the rind disease. 



A bibliography of the subject is appended. 



Resistance in fruits, D. Riaboi (Bml. Vrcd. Selsk. Khoz. [e<c]. No. 4, (1915), 

 p. 1; abs in Mat. Mikol. i Fitopatol Ross., 1 {1915), No. 4, pp. 121, 122). — As a 

 result of his studies of the resistance in fruits to apple scab, the author states 

 that smooth and shiny varieties are more susceptible to this disease than those 

 which have dull, rough, or waxy surfaces. 



The root rot disease of the apple in Virginia, F. D. Feomme and H. E. 

 Thomas {Science, n. ser., 45 {1911), No. 1152, p. 93). — According to the authors, 

 the root rot of apples in Virginia, which is said to be prevalent in the chief 

 orchard districts of the State, is apparently due to a species of Xylaria. They 

 report having found perithecial stromata of X. polymorpha in various stages of 

 typical root-rot attack, and cultures obtained from this fungus are being used 

 for additional experiments. 



Temperature relations of apple rot fungi, C. Brooks and J. S. Cooley 

 (17. S. Dept. Agr., Jour. Agr. Research, 8 {1911), No. 4, pp. 139-164, Pls. S, 

 figs. 25). — A study has been made of a number of species of fungi to determine 

 the temperature relations in connection with the general application of cold 

 storage to fruits. The following species of fungi have been studied at different 

 temperatures and under various conditions : Alternaria sp., Botrytis cinerea, 

 Cephalotheciiim roseum, Fusarium radicicola, Olomerella cingulata, Neofabrwa 

 malicorticis, PeniciUiuiii expansum, Sclerotinia cinerea, Sphceropsis malorum, 

 and Volutella fructi. 



In inoculation experiments with the above species of fungi, all grew at 

 0° C. except the species of Fusarium and Glomerella. The former made no 

 growth at 15, and the latter none at 10°. Sphwropsis malorum produced no 

 evident rot in one week's time at 15°, nor Penicillium and Neofabraea at 10° 

 in two weeks, while Sclerotinia cinerea produced measurable rots at 5° in 

 one week, and at 0° in two weeks. The optimum temperature for A'', mali- 

 corticis was 20, for F. radicicola 30, and for the other fungi 25°. With most 

 of the organisms the growth rate dropped off rapidly above 25, but with the 

 exception of A'^. malicorticis all made some growth at 30°. With most of the 

 fungi the initial incubation stages of growth on the fruit are more inhibited 

 by low temperatures than the later stages, and results obtained show the 

 importance of immediate as compared with delayed cold storage. 



A Phytophthora rot of pear, T. A. O. Schoevees {Tijdschr. Plantenziekten, 

 21 {1915), No. 5-6, pp. 153-159). — A rot of pears noted at Bennekom is de- 

 scribed, which is thought to be due to P. omnivora {P. cactorum). 



Peach scab in Netherlands, T. A. C. Schoevers {Tijdschr. Plantenziekten, 

 21 {1915), No. 1, pp. 26-29, pi. 1; abs. in Ztschr. Pflanzenkrnnk., 25 {1915), No. 

 6, p. 365). — Black scab spots on peaches in Gendringen contained a fungus said 

 to be Cladosporium carpophilum. Monilia fructigena, the cause of brown rot, 

 was also present in abundance. 



A root disease of prunes, Mina A. Willis {Phytopathology, 6 {1916), No. 4, 

 pp. 368, 369). — The author reports the appearance in the summer of 1915 of 

 a peculiar prune disease in the western part of the Snake River Valley, Idaho. 

 In the early part of the season the trees are said to have been apparently 

 normal, but later they wilted and died. Examination showed the entire root 

 system had been destroyed. The sap from diseased trees had a peculiar odor, 

 from which the local name of sour sap was probably derived. 



