June, 1020] PATHOLOGY 



401 



2766. Sr.vKMVN. !•;. C. The black stem rust and the barberry. I. S Depf Affrie Fear 



' s ,;' 1 """"~ factOT '" s """ ' ,oaht "»- A lis! of the common - given v.,il, methods of 



Ml, "« """" "f^ ***»« by colored plates. A v,,, v considerable Qumto o ££ ,, , 



grasses are attacked The black stem rusl (Puecinia gr nU) has many forms E are 



sp 7 ,u ; '" a1 : "' ■ ,h " ""*»* of the rust is given in detail, illustrated. The rust ™ 



seeds does not mfect young sprouting grain. The summer spores (uredo cannotwinter 



«**, *the gul f ^states and in California. There is n igration fronTtl ,',, 



Rust damage can be .reduced by proper soil management, early sowing, seeding witb resistant 

 varieties of grams destruction of rusting grasses, and eradication of barbeny. The Z 

 tancfl of the role of barberry was shown by tracing infection of grains to bushes located from 

 eighty rods to a mile or more away, so that barberry bushes located in towns may be the cause 

 of a severe rust in the surrounding country. A discussion of the various varieties of barber- 

 nes and heir re ation to rust is given. Of the numerous species, two types of barberrv are 

 distinguishable, those that resemble Berberis vulgaris which carry rust and those resembling 

 Berberxs thunbergtt which do not carry rust.-Denmark has solved the rust problem bv eradi- 

 cating the barberry. A history of barberry laws is given. Sentiment for eradication of bar- 

 berry is increasing and should be fostered.— C. J. Shirk. 



XV, V 57 ; S 7riTt GE T E - Twent y- ei g hth an ^l report for the year ending June 30, 1918. 

 ^ashnigton [State] Agric. Exp. Sta. Bull. 153. p., 8 fig. I919.-See Bot. Absts. 3. Entry 



2758. Severin. H. H. P. Investigations of the beet leafhopper (Eutettix tenella Baker) 

 in California Jour. Econ. Entomol. 12 : 312-326. PL 15. I919.-The source of the beet leaf- 

 hopper in the spring its hibernation through fall and winter, native plants from which it 

 transmits leaf curl to beets {Beta vulgaris) and related cultivated plants, life history and re- 

 lated topics are discussed. The hoppers leave the native vegetation in the spring for the 

 more succulent plants of the cultivated fields and return to the native plants in the fall. 

 This fact has important bearing on the time of planting sugar beets. Beets planted in No- 

 vember, December and January in San Joaquin Valley, conditions being favorable, usually 

 produce good crops, though with an increase in number of plants producing seed stalks (with 

 lower sugar content) early, and tougher roots. The young plants are sometimes killed by 

 frost when planted early .-The disease was transmitted to sugar beets from the following 

 plants by transferring hoppers: Atriplex elegans, A. semibaccata, Sessuvium sessile, Larrea 

 f«oncata and Erodxum cicutarium; Bur clover (Medicago hispida) developed curly leaf when 

 attacked by beet leafhopper from Erodium cicutarium, bur clover, and grass. Non-virulent 

 adults reared from eggs and kept on black mustard (Brassica nigra) failed to transmit the 

 leaf curl to beets when allowed to feed previously on cresote bush (Larrea divaricata), obtained 

 rom the Mojave desert and Imperial Valley; a non-virulent hopper transmitted the disease 



I , 68 ,"? al lT^ t0 eed previousl y on lowlan <* purslane (Sessuvium sessile) collected at 

 Niland, but two failed to transmit the disease when fed on purslane from "Dixieland.' -Leaf- 

 hoppers bred from the following plants transmitted curly leaf to beets: Atriplex rosea, A. 

 expansa, Salsola hah, var. tenuifolia, Amaranthus retroflexus, Am. qraecizans, Am. deflexus, 

 Sessuvium sessile, Brassica arvensis and Solarium nigrum var. douglasii.-A study of the sea- 

 sonal migrations of the leafhoppers from native plants in the spring to cultivated beets and 

 return to native vegetation in the fall, suggests a cycle of plants which harbor the disease 

 — A. B. Massey.v 



49 2 p, 9 '/, HA /° VALOV ' M ' S ° me potential P ara sites of the potato tuber. Phvtopath. 9: 36- 

 rr* L , S > fi9'J- g - 1919.— Potato tubers of the Irish cobbler variety were inoculated with 

 the mycelium of pure cultures of Penicillium oxalicum, Currie and Thorn, Aspergillus niger 

 van liegh. and Clonostachys araucaria var. rosea Preuss. and rots resulted which progressed 

 quite as rapidly as did those produced in tubers by Fusarium radicicola. The author considers 

 these organisms to be potential parasites which should be given some serious consideration 

 because of the possibility of their becoming progressively more parasitic.-.Vaude Miller 



