DISEASES OP PLANTS. 745 



As a result of the author's studies, he is couviuced that for the farmers of 

 the Northwest the formaldehyde treatuieut. as used for the preventiou of 

 stlukiug smut of wheat aud loose smut of oats, and the modified hot-water 

 treatment for the pi'evention of loose smut of barley aud wheat will give the 

 most satisfactory i-esults. For the flax diseases the separation of all light 

 seed and the treatment of the heavy seed with formaldehyde is recommended. 



For the treatment of seed various methods have been devised, and a number 

 of successful forms of machinery for treating grain are described. 



Maize smut, T. H. Johnston (Agr. Gaz. N. /?. WaJc.-i, 21 {1910), No. 1, pp. 

 43, -'I'l. figfi. 2). — The author gives the following as the smuts of New South 

 Wales: Maize smut {Ustihigo may (lis), two barley smuts (U, hordci and 

 T'. iiitda), the loose smut of oats {U. avcruc) and of wheat ( f ^ tritiri). bunt 

 or stinking smut of wheat {TUlctia tritici and T. Iwvis), flag smut of wheat 

 {Urocystis occulta), and another smut (TJsWago sp.) on couch grass. A 

 popular description of the life history of the corn smut and remedies for its 

 control are given. 



Smut in wheat {Agr. Gaz. N. 8. Wales, 21 {1910), No. 1, pp. 58, .5.9).— Atten- 

 tion is called to the fact that F. Maddox 15 years ago conducted a series of ex- 

 periments (E. S. R.. 9, p. 10.57) on smut infection of wheat by loose smut 

 {Ustilago carho), which showed that flower infection was its only means of 

 propagation, a conclusion that has since been confirmed by other investigators 

 (E. S. R., 10. p. 676; 19, p. 7.50; 21. p. 445). 



The flower infection of wheat smut, W. Lang {Centhl. Bal:f. [rtr:], 2. AM., 

 25 (1!)09), No. 1-J,, pp. 86-101, pJ. 1, figs. 2).— A general history of the study 

 by various Investigators of the propagation of the grain smuts is given, fol- 

 lowed by observations on the chai-acters of the spores, their germination, in- 

 fection, and subsequent path of the germ tube down the stigma to the embryo, 

 the entrance of the mycelium into the embryo and its final wintering over in 

 the grains of wheat. It is claimed that the spread of the snuit is mainly by 

 liloom infection and that the weather conditions at this period have much to 

 do with the success of the infections. Breeding varieties of wheat the seed 

 coats of which are able to prevent the entrance of the mycelia into the 

 embryo during the blooming season is recommended. 



The propagation of Sclerospora niacrospora by means of wheat kernels, 

 Y. Peglion {Atli R. Accad. Liiicei, Rend. CI. Sci. Fis., Mat. c. Nat., 5. so:. 11 

 {1908), II, No. 9, pp. 509-511; ahs. in Centhl. Bakt. [etc.], 2. Al)t., 26 {1910). 

 No. Jf-5, p. 108). — It is stated that this fungus infects the young ovaries of the 

 wheat, which at maturity show no external signs of disease, but on examina- 

 tion reveal an abundance of mycelia within the i)ericarp of the seed. When 

 the wheat is planted and germination occurs, this enclosed mycelium also 

 grows and easily penetrates into the tender tissues of the wheat seedlings. 

 By this means direct ])ropagation and dissemination of this mildew are accom- 

 plished through apparently sound seed. 



Smut infection of wheat by means of infected manure, soil, and seed, B. 

 Steglicii {FlihJing's Landin. Ztg.. 58 {1909), No. 20, pp. 738-7J,2; Landir. Vers', 

 i^tat., 72 {1910), No. 5-6, pp. 3-'f4-350). — The results are given of a series of 

 experiments to test the smutting of wheat from manure, soil, seed, and bran, 

 each of which had been infected with the spores of a smut {Tilletia Iwvis). 



It was found that manure mixed with smut spores was able to infect the 

 seedling wheat slightly, but the percentage of infection was very small when 

 the manure was left in heaps from 15 to 30 days and then spread on the ground 

 immediately before the sowing of the wheat. The infection from the soil was 

 much greater than from manure, aud when smutty seed was used the infection 



