150 EXPERIMENT STATION EECOKD. [Vol.37 



names Bacillus carotovorus, B. oleracecE, B. tnelonis, B. aroidece, and Psendo- 

 nionas destrnctans. Soft rots of potato are associated with B. solanisaprus and 

 a Fusariara, black leg with B. phytopMliorus and with a Rhlzoctonia. Bac- 

 terial wilt of cruclfers, also called black rot of cabbage, or brown rot, is asso- 

 ciated with P. campestris, and bacterial wilt of cucurbits with B. traclieiphilus. 

 Bean blight, or bacteriosis. is associated with P. phaseoli, which organism 

 appears to be, as regards morphological and cultural characteristics, practically 

 identical with P. campestris. It is not, however, pathogenic for cabbage or 

 cauliflower, while P. campestris is pathogenic for most crucifers but not for 

 legumes. 



Club root of crucifers and its control, E. Wkkth (A'. Biol. Anst. Land it. 

 Forstiv. Fltighl., 56 {1916), pp. 3, fig. 1). — This circular deals with Plasmodi- 

 ophora hrassicoe, its persistence in spore form in the soil, its infection of sub- 

 sequent crops, and its effective control. 



Excess of .soil water, deficiency of lime, use of one-sided fertilizers, too long 

 a succession of cruciferous crops, and the presence of wild crucifers in fields 

 are among the conditions favoring the perpetuation of the club root organism. 

 Rigid inspection of plantlets. judicious rotati«n of crops, improvement of physi- 

 cal and chemical conditions in the soil (especially deep plowing with a liberal 

 use of lime), and disinfection of the soil with .5 liters per square meter (4.4 

 qts. per square yard) of a 2 to 3 per cent solution of formalin are among the 

 measures recommended. 



A new host of Ascochyta hortonim, L. Gajjotto (Riv. Patol. Veg., 8 (1916), 

 Xo. 2, pp. ^5. 4S). — The author records a fungus, supposed to be A. horturum, 

 as causing an external spotting and an Internal rot of artichoke. 



Controlling cabbage yellows, S. N. Grekn and J. G. Uumbebt (J/o. Bui. 

 Ohio Sta.. 2 (1917). Xo. 2, pp. 37-40. fig. 1). — An account ia given of experiments 

 begun in 1911 to develop by careful selection strains of cabbage resistant to 

 the yellows disease caused by Fusarium conglutinans. A« a result of these 

 experiments, several resistant strains of a commercial varietj of cabbage have 

 been developed. 



Potato diseases, F. D. Heau) {Washirigton Sta. PopnJ^r Bui. 106 {1917), 

 pp. 15-94. fiffs- 26). — After a discussion of the loss due to potato diseases, some 

 of their causes, and methods of prevention and control, the author describes 

 nonparasitic di.'Jeases. due to unfavorable environment and chemloil treatment, 

 and those transmitted by seed, the cau.se of which is unknown, and parasitic 

 diseases due to bacteria, slime molds, and fungi. 



Important potato diseases and their control. R. Schandek {Arb. Gesell. 

 Ford. Baucs u. Vcrweiid. Kartoffeln, Xo. 4 {1915), pp. 90, flfft. 19). — This is a 

 synthetic review, chiefly from a practical standpoint, of the principal potato 

 diseases prevalent in Germany, including nematode attack, their effects, and 

 their control. 



The osmotic pressure of cell sap in relation to tobacco plants affected with 

 mosaic disease, A. Sprecher {Ann. Jard. Bot. BuHenzorg, 2. ser., 14 {1916), pt. 

 2, pp. 112-128). — Tlie author, describing a series of studies, states that tobacco 

 plants afrecte<l with mosaic di-sease show practically the same freezing iwint 

 and o.smotic pressure as normal plants. The former, however, show lower 

 molecular weights in the .substances dissolved in the cell sap, this fact being 

 supposedly connected with a small content In organic, and a large content in 

 mineral, substances. 



Tomato fruit diseases. R. Waters {Jour. Agr. [Xew Zeal.]. 12 {1916), Xo. 3, 

 pp. 19S-201. figs. 4)- — Notes are given of tomato black rot due to Mncrosporium 

 tomato, probably identical with M. solani; circular white patch, supposedly 

 Induced by unfavorable weather conditions ; and premature softening, which 



