DISEASES OF PLANTS. 875 



siniii and the percentage presenl in the plats the seed Cor which had received 

 other treatments was greatly reduced. 



A brief account is given of \ xperimenl to tesl the claims thai naptha 



powder mixed with wheal or oats will prevent the rusl of those grains. The 

 results of the investigation showed thai the application of the chemical bad no 

 effecl whatever In reducing the amounl of rust. 



Rust in oats, A. II. Co< kayne | Vetc Zeal. Dept. Igr., Div. Biol, and Hort. Bui. 

 .;. i>i>. D. ///-v. 2). A general account is given of cereal rusts, after which note- 

 are presented <>u the Injury caused by those attacking oats, Puccinia coronata 

 and /'. graminis avena being of the greatesl economical importance. 



Numerous spraying experiments were carried out with copper sulphate, '•••mi 

 celeste, ammoniacal copper carbonate, Bordeaux mixture, iron chlorid, iron -ni 

 phate, and potassium bichromate. The attacks of rusl .-ire soinev* li.it diminished 

 by the use of Bordeaux mixture, eau celeste, and potassium bichromate, hut the 

 expense and method of treatmenl render it impracticable. 



From the present knowledge of the subjeel the author st.-ites thai Bpraying is 

 of no practical use. and thai the production of rust proof varieties offers the 

 most promising method of combating cereal rusts, in order to reduce the ten 

 dency to disease the author recommends care in the use of manures, particu 

 larly those containing a high amount of nitrogen, careful drainage, the removal 

 of all weeds ;ind wild plants which .ire liable to be host plants for the rusts. 

 early sowing, and where a crop is badly infested, the burning of the straw. 



Bordeaux mixture for the potato blight, ( '. A. Z.wriz < \un. Rpt. Ontario 

 Agr. Col. 'mil Easpt. Farm, SI {1905), />. 199). — An account is given of spraying 

 experiments with Bordeaux mixture for the control of the potato blight, in 

 which the investigations have been carried on for a number of years. The past 

 year .". sprayings were given, and the average results show that there was less 

 rot on the potatoes on which Bordeaux mixture and Paris green were used than 

 on those where Paris green alone w;is applied. The :; applications of Bordeaux 

 mixture did not seem sufficient to prevent all the rot. and it is probable that 5 

 or <"> applications should he made. 



The prevention of potato rot, F. Pabisot (Jour. Agr. Prat, u. ser., 9 ( 1905 ), 

 No. 26, ii/i. 821, 822).— After describing the potato rot and its effecl upon the 

 crop, the author gives suggestions for its control. 



Among the fungicides recommended he prefers the Burgundy mixture, which 

 consists of copper sulphate 2 kg., sodium carbonate i,500 gin., and water to make 

 100 liters. This should he thoroughly sprayed over the plants, using from 1U to 

 L5 hectoliters per hectare. This fungicide is recommended on account of its 

 greal adhesiveness. When properly made a gelatinous precipitate is formed, 

 and to gel this in the besl condition the mixture should he made cold. The color 

 of the solution should he a clear blue. A greenish coloration is an indication of 

 improper mixing. 



Treatment for potato scab, ( '. A. Zavitz (Ann. Rpt. Ontario Agr. Col. and 

 Expt. Farm, •»'/ (1905), m>- 200, 201). The author describes the treatment of 

 seed potatoes with corrosive sublimate solution for the prevention of scab, and 

 although in general the crop showed hut a relatively small amount of scab, the 

 results <>f the experiments indicate that the treatment will he :i successful one 

 Where a SCabby crop is to he expected. 



The white rust of tobacco and the mosaic disease, <;. Delacroix (Compt. 

 Rend. Acad. 8ci. [Paris], (40(1905), Vo. /". />/'• 678-680). -In 1894 the author 



in conjunction with E. Prillieux described a disease of tobacco that has since 



been considered as identical with the saic disease (E. s. R., :.. p. 1010). At 



that time it was claimed to he of bacterial origin, hut the author now believes 



