590 EXPERIMENT STATION RECORD. 



Brief uoU-h are {2;iven on a nnml)cr of parasitic fungi whicli liavo been ol)served in 

 German East Africa, and tlescriptions are given of several which are considen-d as 

 hitherlo undescribed. Among tliose described are Limacinia tangensis, which has 

 been found parasitic upon mangoes and also on the cocoanut palm, Ztikalia shihlman- 

 niana on seedlings of the cocoanut palm and other species of palms, Pleomoliola 

 h;/ph:mcs on the leaves of PIyph;ene, and Asterina stuhlmanni on pineapi)le leaves. 



Precautions against rust of cereals, H. Hitier {Jour. Agr. Prut., n. ser., 6 

 {J90.>), Xo. 40, jip. 4-35, 4o6). — Attention is called to the influence of soil, fertilizer, 

 rotations, time of seeding, etc., on the production of cereal rusts. In order to pre- 

 vent tiieir destructive occurrence the author recommends the selection of resistant 

 varieties^, early seeding, and proj^ier fertilization of the crop. 



A bacterial disease of rice, P. Voglixo {Turin: Derossi, 1902, pp. 48,fgs. 11; 

 abs. in Bot. Centbl., 93 {1903), No. 37, pp. 274, 275). — An account is given of a disease 

 of rice known as Brusone, in which the history, description of the disease, its path- 

 ology, etiology, and results of artificial inoculation experiments are included. 



This disease, which has been known for some time, has been attributed to a great 

 number of causes, such as climatic conditions, physical conditions of soil, various 

 fungi, etc., all of which are reviewed by the author. From his observations he is 

 led to believe that the disease previously described as due to Pi/ricularia oryzw, is in 

 reality caused, in many instances at least, by the bacteria which are found i)resent in 

 the discolored tissues and which he has called Bacillus oryzie. He states that bacteria 

 have recently been found in Japan accompanying this disease, and that what has 

 been frequently attributed to the above-named fungus is really caused by the bacteria, 

 the fungus occurring as a secondary agent. 



The bacteria are found to develop with great rapidity in acid media, and as the roots 

 seem to be the portion first attacked, the author recommends rendering the soils 

 neutral or slightly alkaline by the addition of lime to them. All attempts to combat 

 the disease by fungicides have failed, and at present the use of lime and the selection 

 of resistant varieties seem to be the most practical means of combating the disease. 



The specialization of Erysiphe graminis, E. Marchal {Compt. Rend. Acad. 

 Sci. Paris, 136 {1903), No. 21, pp. 1280, i;?.?i).— In a previous publication (E. S. R., 

 14, p. 667) the author has given the results of his investigations with cross inocula- 

 tion of the conidia of this mildew on certain grasses. He has continued his investi- 

 gations and in the present paper reports experiments in cross inoculation with the 

 ascospores of the fungus. 



A number of cereals and grasses were inoculated, and as a result of the experiments 

 it is claimed that no difference was observed between inoculations with the ascospores 

 and where the conidia were employed. This is said to prove the specialization of 

 the parasitism of this mildew, it having developed certain physiological races which 

 are well established and which can not be carried from one host to another except 

 within very definite limits. 



Notes on the biolog-y of Cystopus candidus, A. Ebebhardt {Centbl. Bakt. u. 

 Par., 2. Abt., 10 {1903), No. 20-21, pp. 655, 656).— A study was made of the biology 

 of the white rust of cruciferous plants, and it was found possible to cross inoculate a 

 number of host plants with the conidia of the fungus. There appeared to be no 

 specialized forms of the organisms which were limited to certain genera or species of 

 Crucifene. Similar investigations with the conidia of the form growing upon salsify 

 showed that this species was confined to this and closely allied host plants. 



Some observations on crown gall of apple trees, W. B. Alwood ( Virginia 

 Sta. Bui. 140, pp. 1S7-212, figs. 11) . — Previous to 1896, the author states, there was 

 practically no acquaintance in the State with the crown gall of apple trees, but the 

 inspection work in connection with the San Jose scale showed that this disease was 

 prevalent and since that date it has increased to an alarming extent. 



