DISEASES OF PLANTS. 541 



to Marasmius sacchari, said to be often associated with some other fungi ; rind 

 disease, due to Melanconium sacchari ; red rot of the stem, due to CoUetotrichum 

 falcatum; pineapple disease, due to Thielaviopsis paradoxa; and red spot of 

 the leaf sheath, due to Cercospora ragincc. Some others found caused serious 

 injury only under exceptional conditions. 



On the identity of Bacillus nicotianse with B. solanacearura, J. A. Honing 

 {Rec. Trav. Bot. N6erland., 10 {191S), No. 2, pp. 85-136, figs. 3).— The author, 

 giving an account of studies on the morphology and parasitic activity of the 

 organism associated with " gummosis," black shank, or bacterial tobacco wilt, 

 states that B. nicotianw, described by Uyeda (E. S. R., 18, p. 151), is Identical 

 with that previously described as B. solanacearum by Smith (E. S. R., 8, p. 

 895). 



It is stated that this organism may sometimes be observed to lose its viru- 

 lence, first for Capsicum annuum, later for Nicotiajia tahacum, and finally for 

 SoUnium mclongena and S. lycopersicum. This circumstance probably tends 

 to explain the disagreement noted in the reports above mentioned. 



Weather and stalk disease of wheat, E. Voces (Deut. Landw. Presse, 40 

 (1913), No. 83, pp. 993, 99/f, figs. 5).— The author reports finding on wheat 

 affected with foot rot or stalk disease besides Ophiohohis herpotrichus a num- 

 ber of other fungi named, and he holds that in this disease, as probably in some 

 others, different causes may produce very similar results. 



A discussion of the weather in connection with the progress of certain crop 

 diseases during the past three years concludes with the statement that weather 

 exerts both direct and indirect influence upon the relations between host and 

 parasite. 



Studies on frost injury to finiit trees, P. Sorauer (Naturwvssenschaften, 

 1 (1913), Nos. U, PP' 1055-1058, figs. 4; 45, pp. 1094-1097, fig. l).—lt is stated 

 that even moderate cold is capable of producing wounds in fruit trees in re- 

 gions of loose cortical tissue, particularly in case of certain varieties named. 

 The attacks of fungi are favored by the lesions produced. Both these features 

 are accentuated in case of quick-growing trees under the influence of nitroge- 

 nous fertilizers with free irrigation. 



Winter injury in orchards, F. M. Clement (Ann. Rpt. Quebec Soc. Protec. 

 Playits [etc.], 5 (1912-13), pp. 24-26).— The observed effects of expansion and 

 contraction in splitting the bark of fruit trees are discussed in connection with 

 their relation to attack from organisms causing disease. These injuries (be- 

 lieved to favor development of black rot canker and crown rot in apple trees) 

 are said to be prevented or greatly minimized by protecting the trees from 

 strong wind and direct sunshine. 



The black spot of the apple and pear, H. M. Nicholls (Agr. Gaz. Tasmania, 

 21 (1913), No. 10, pp. 387-401, figs. 6).— Besides a brief illustrated description 

 and biological history of Venturia inwqualis and V. pyrina, causing black spot 

 respectively of apple and pear, some remedial measures as tried in Tasmania 

 are recommended. These are essentially the same for both fungi and consist 

 in early plowing in of the fallen leaves, harrowing down the surface soon 

 after, leaving it undisturbed until after November 15, and siiraying the trees 

 early in October with Bordeaux or Burgundy mixture, or with lime sulphur 

 adding 1 lb. of wheat flour to each gallon of the solution to promote spreading and 

 adhesion. For the control of the disease in packed fruit, good ventilation is 

 said to be usually effective. 



Quince blotch and apple fruit spot, C. Brooks (PhytopathoJogu. 3 (1913), 

 No. 4, PP- 249, 250). — The author notes the occurrence on Chinese quince of the 

 fungus Phoma pomi, and calls attention to the identity of this species with 

 that from the apple and other species of quinces. 



