146 EXPERIMENT STATION RECORD. 



Melumpmru amygdaVmn' proved to be autcecioii8, occurring in both forms upon Salix 

 spp. The experinientis with the Puccinia of Carex showed its fecidial to be passed 

 upon species of Kibes. The complex biological group of Puccinias found on Phalaris 

 arundinacea were investigated and their fecidial hosts determined. F. jtludaradis has 

 for its secidial host Arum macuhdam. P. sessUk, including tlie form d.ig)'uj)hidis, has 

 for its secidial hosts various species of liliaceous plants, and /'. orchidearum upon 

 several genera and species of orchids. 



Seed treatment for the prevention of bunt of wheat ( Jour. Bd. Agr. [Lou- 

 donl, 7 {1900), Nu. 3, pp. 352,353). — ii brief account is given of experiments in which 

 seed of wheat badly affected with smut ( TiUetia caries) was treated with a solution 

 of copper sulphate at the rate of 1 11>. to 1 gal. of water. This amount of solution 

 was used upon 4 bu. of wheat, being poured over the grain and thoroughly stirred. 

 The resulting crop was entirely free from the disease, while an adjacent plant, grown 

 from a similar lot of untreated seed, gave 4.66 per cent of badly snmtted stalks. 



Potato scab and its prevention, L. R. Jones and A. W. Edson ( Vermont Sta. 

 Bid. 85, pp. 111-120, figs. 2). — The cause of the potato scab, its occurrence and 

 appearance, are described in a popular manner. The development and spread of the 

 organism through the soil is shown, and the relative resistance of a number of varie- 

 ties of potatoes pointed out. Means for prevention of the potato scab are described, 

 among them soil treatment of different kinds, such as rotation of crops, proi>er selec- 

 tion of fertilizers,. use of fungicides on the soil, etc. The disinfecting of seed potatoes 

 as a means for the prevention of the disease is described, soaking them in corrosive 

 sublimate or formalin solutions being recommended. The effect of formaldehyde 

 gas was investigated to a limited extent, and the authors believe that it will prove an 

 advantageous method of treating potatoes for the prevention of scab. 



Potato blight and its treatment, D. A. Brodie {Washington Sta. Bid. 46, p>p. 

 15, figs. 5). — The author gives a popular description of the fungus Phytopldliora ivfes- 

 tans, which is a cause of considerable injury to the potato crop in his region. The 

 results of experiments in which plants were sprayed with Bordeaux mixture are 

 given. The average increase of the sprayed over the unsprayed areas was nearly 37 

 per cent. The sprayed plants remained green much longer and were not as severely 

 injured by the ravages of cutworms, which proved very destructive. It is recom- 

 mended that spraying should begin about the middle of June, and the applications 

 be repeated every 2 weeks during the growing season. Directions are given for the 

 preparation of the Bordeaux mixture. 



Unsatisfactory growth and premature death, of cane as the result of root 

 disease, Z. Kamekling and H. Stkingak [Reprint from Arch. Jam tSuikcriml., 1900, 

 No. 18, pp. 24). — A disease of sugar cane that has caused nmch loss and is commonly 

 known as " dongkellanziekte " was found to consist of 2 diseases, a root rot and 

 another root disease. The latter has its center in Djoca, while the root rot has 

 appeared all over Java and is especially bad along the seacoast. Inquiry among 

 sugar planters has shown that this disease is most destructive on plantations that 

 have been in operation for more than 40 years; that on plantations opened between 

 1860 and 1880 there is but little root rot, and that those established since 1880 are 

 practically free from it. 



It is therefore a trouble met with only on ground that has been long useil for grow- 

 ing sugar cane. It is claimed to be the result of soil exhaustion, which is prol)ably 

 dependent upon a change in the physical condition of the soil. Facts to sustain this 

 theory Avill be given in a future ])ai)er. — n. >r. i>ieters. 



Observations on the mosaic disease of tobacco, A. F. Wood {Ahs. in Science, 

 n. ser., 13 {1901), No. 320, j^p. 247, 248). — As a result of numerous experiments con- 

 ducted by the author, it is stated ihat the mosaic disease of tobacco can be artificially 

 produced in a mmiber of ways, as liy cutting l)ack plants at any stage of active growth, 

 by repotting or transplanting a plant during active growth and thus stimulating a 



