No. 2, March, 1921] PATHOLOGY 185 



cynosbati), two or three applications being necessary to kill. Spraying the foliage kills in 

 from a half hour to a few hours. Efficiency of dip oil is little effected by rain, sunlight, 

 absence of foliage, or season. Fuel oil alone is effective if two or three applications are made. 

 Neither oil is poisonous to animals. Treatment is economical where pulling is difficult. 

 Compressed-air hand sprayers were used. — W. H. Rankin. 



1247. Robertson, W. H. Commercial and home-made lime-sulphur spray. Agric. Jour. 

 [British Columbia] 4: 375. 1919. 



1248. RoDDA, T. E. Control of brown rot on peaches. New Zealand Jour. Agric. 20: 

 20-23. 1920. — Brown rot did not develop to any extent on account of the dry season. Fruit 

 was treated to prevent development of brown rot after picking. Dipping in bluestone 1-10 

 or 1-20 caused fruit injury, while 1-40 was apparently safe. Formalin solution 1-50 produced 

 spots on the fruit, while 1-100 did not injure it. Lime-sulphur solution 1-15 and 1-30 did 

 not affect fruit, but the 1-15 left too heavy a deposit on the peaches. Permanganate of 

 potash 1-640 did not injure fruit. Applications of Bordeaux powder, sulphur dust, and a 

 lime-sulphur dust were unsatisfactory. Fumigation with sulphur (i oz. per 100 cu. ft.) 

 and with formalin (§ oz. per 100 cu. ft.) injured the fruit. — A'. J. Giddings. 



1249. ScHAFFxiT, E. Versuche zur Bekampfung des Kartoffelkrebses im Jahr 1918/19. 

 [Control experiments against Potato Canker (Black wart.] Zeitschr. Pflanzenkrankh. 30: 59-67. 

 1920. — Author states that soil disinfection experiments gave no practical results. He then 

 discusses the results of experiments relative to resistance of potato varieties to Chryso- 

 phlyctis endobiotica. Of the varieties tested for five years the following proved immune: 

 (1) Early: Sechswochen (verbesserte lange), Poppehurt; (2) Medium Early: Koralle, Lech; 

 (3) Medium Late: Danusia, Jubel, Ada; (4) Late: Agraria, Erika. A number of the varie- 

 ties tested for a period of four years also remained without attack. — It is important to note 

 that some varieties proved immune for one year or several years, but were slightly attacked in 

 other years. This observation is explained as due to the use of "deteriorated" seed. Author 

 suggests that the immunity of the varieties mentioned is not absolute, but only relative; 

 that varieties showing immunity under normal conditions may lose this faculty as soon as 

 the plant no longer exhibits its normal form of development and is weakened in its physio- 

 logical functions, as a result of pathological conditions transmissible through the seed tuber. 

 The contrasting results given by author in support of his argument seem to substantiate his 

 findings. Hence there exists in these varieties and in their behaviour towards the causal 

 agent of potato canker a classical example of immunity and "predisposition" (in Sorauer's 

 sense) of plants according to their constitution in their relation to a pronounced parasite. 

 The use of varieties of proven immunity on infected lands is recommended under proper 

 legislative safeguards. — H. T. Giissow. 



1250. ScHOENE, W. J. Twelfth report of the State Entomologist and Plant Pathologist 

 1918-1919. Quart. Bull. Virginia Crop Pest Commission 1^: 1-28. 1920.— Contains brief 

 notes on the following topics: Inspection for pine blister rust; cedar rust and cedar eradica- 

 tion; "Take-all" disease of wheat in Virginia. — F. D. Fromme. 



1251. Selby, a. D., and R. C. Thomas. Bordeaux mixture an active fungicide. Monthly 

 Bull. Ohio Agric. Exp. Sta. 5: 220. July, 1920. 



1252. Shapovalov, Michael. The potato-scab control problem as it stands to-day. 

 Potato Mag. 2'i: 8-9, 26. 3 fig. 1920. 



1253. TiCE, C. Certified potato seed production. Agric. Jour. [British Columbia] 5: 197. 

 1920.— See Bot. Absts. 7, Entry 665. 



1254. Vayssiere, P. [Rev. of: Vermorel (V) and Dantont (E.) Composition chimique 

 des Bouillies sulfo-calciques employees centre les Insectes et les Maladies des plantes. W p. 

 Montpellier et Villefranche, 1919. (Chemical composition of lime sulphur used in combating 

 insects and diseases of plants.)] Bull. Soc. Path. Veg. France 7: 86. 1920 — C. L. Shear. 



BOTANICAL ABBTRACrS, VOL. vn, NO. 2 



