DISEASES OF PLANTS. 243 



A dry scab of potatoes (Jour. lid. Am: [London], 16 {1909), Xo. 7, pp. 

 SI. ,i.^). — A brief tleseriptioii is <;iven of a disease of potatoes due to ,^iJondylo- 

 cladiiini, airoinrcns. Tlie injury is confined to the tubers and there are no 

 Indications of the presence of the fun.i^us on the foliage. It causes a disfigure- 

 ment of the surface of the tuber, followed by local spots of dry i"ot. All 

 affected potatoes should be rejected in planting. 



Investii^ations on the leaf curl disease of potatoes, T. Remy and G. 

 Schneider (FiiliUng's Lundio. Ztg., 58 (1909), No. 6. pp. 201-219, map 1) .— 

 After discussing the various causes that have been claimed to induce the leaf 

 curl disetise of potatoes, the authors give an account of its distribution in 

 the Rhine Provinces, in some parts of which the potato yield for 1908 is said 

 to have been reduced fully 50 per cent by reason of the disease. 



The relative susceptibility of different varieties of potatoes to the disease, 

 as determined by o years' observations, is shown. The relation of soils. Aveather, 

 and situation to the disease is discussed. Weather conditions are held to be 

 only incidental to the development of the disease, although the worst outbreak 

 came in a season which was characterized by cool, moist weather in May, fol- 

 lowed by hot weather in June, with considerable rain and an unusually hot 

 and dry autumn. Varieties that had been previously only slightly affected 

 were severely attacked during this season. 



There appears to be evidence that the disease may be spread through seed 

 tubers, and only sound potatoes of the most resistant varieties should be used 

 for seed purposes. 



The potato harvest of 1908 and the leaf curl disease, O. Appel {IUus. 

 Landio. Ztg., 29 {1909), 'No. 18, pp. 176-178). — An account is given of the 

 diminished yield of potatoes in Germany in 1908, and the relation of the leaf 

 curl thereto is pointed out. 



A contribution to the study of brusone of rice, U. Brizi {Ann. 1st. Agr. 

 [Milan], 7 (1905-6), pp. 107-17^).— -A critical review is given of literature relat- 

 ing to the disease of rice known as brusone. The author claims that the dis- 

 ease is due in the first place to physiological disturbances of the root system 

 resulting in incomplete respiration, and in functional disturbances that ai*e 

 finally changed into true lesions on the root system. These may precede exte- 

 rior manifestatio?! of the disease. He further claims that brusone can not be 

 attributed solely to fungi occurring on the aerial portions of the plant. 



Report of plant pathologist, F. M. Rolfs (Missouri Fruit 8ta. Rpt. 1907-8, 

 pp. 16-18, pi. 1). — The work done in plant pathology during the biennial period 

 covered by this brief report has consisted of a general survey of the fruit dis- 

 eases of the State, a preliminary report of which has been noted (E. S. R., 20, 

 p. 347 ) . The work has since been continued along similar lines, considerable time 

 being given to the investigation of the diseases of the peach, plum, and apple, 

 while some attention has been given to those of the blackberry and raspberry. 



In the laboratory a careful study made of Cytospora ruhesccns and Valsa- 

 Ivucostoina occurring on peach and plum trees has shown that the Cytospora, 

 which is very common on stone-fruit trees, is the pycnidial form of the other 

 fungus. This organism is said usually to gain entrance to the trees through 

 the buds, and when infecti(tn occurs on the trunks and the conditions are 

 favorable for its growth it produces large wounds which are often si-oken of as 

 "sun scald." A full account of the iii\(;stigatious leading to th^^ discovery of 

 the relationshii) between these two fungi will be issued soon. 



Brief notes are given on the defoliaticm of peach trees, due to the bacterial 

 shot hole disease, and on the root rots of peach and apple trees. 



