DISEASES OF PLANTS. 153 



In the cultural tests on interchanges of hosts by the specialized foi-ms of 

 P. graminis the following results are reported: Uredospores from rye infected 

 Tritlcum repens, T. caninum, Dactylis glomerata, and sparingly Bromus secali- 

 nus and B. inermis, but did not infect wheat, oats, or barley ; uredospores from 

 oats infected Arrhenatherum elatius, Avena tmhescens, Alopecurus pratcnsis, and 

 Festuca ovvna, and sparingly Bromus arvcnsis and Briza media, but not rye, 

 barley, or wheat; uredospores from wheat infected barley, Triticiim repens, T. 

 caninum, Lolium peremie, and Festuca gigantea. Uredospores from Aira 

 ccespitosa were unable to infect any of the cultivated cereals or wild grasses 

 inoculated. Uredospores from Agrostis alha infected wheat, oats, rye, barley, 

 Triticum repens, Dactylis glomerata, Bromus secalinus, B. inermis, Aira c<cs- 

 pitosa, and Apera spica vcnti. Uredospores from Poa compressa infected P. 

 compressa and P. serotina but not wheat, rye, oats, or barley. Uredospores 

 from Apera spica venti and Calamagrostis cpigeios were unable to infect any 

 of the cereals or wild grasses inoculated. Uredospores from Arrhenatherum 

 elatius infected oats but none of the other cereals. Uredospores from barley 

 infected barley, wheat, and Triticum repens. 



Experiments were also conducted with the secidiospores from Berberis ob- 

 tained by sporidia infection from various grasses with the following results: 

 ^cidiospores from rye sporidia infected rye, Triticum repens, Dactylis glome- 

 rata, and Bromus secalinus; those from wheat sporidia infected wheat, barley, 

 and T. vulgarc; those from oat sporidia infected oats only; those from barley 

 sporidia infected bnrley, wheat, T. repens, and Lolium perenne; those from 

 T. repens sporidia infected I'ye, barley, wheat, T. repens, D. glomerata, and L. 

 perenne; those from D. glomerata sporidia infected rye, T. repens, D. glomerata, 

 and B. secalinus; those from B. secalinus sporidia infected rye, T. repens, D. 

 glomerata, and B. secalinus; and those from L. perenne sporidia infected barley, 

 wheat, T. repens, and L. perenne; while those from Apera spica venti, Arrhena- 

 therum elatius, Poa compressa, and Agrostis alba sporidia infected only the 

 original host grass in each instance. 



Treatment of seed wheat for smut, II. F. Roberts and P. W. Graff (Kansas 

 Sta. Circ. 12, pp. // ) . — Directions are given for the seed treatment of wheat for 

 the prevention of loose and stinking smut. For the stinking smut the best 

 treatment is said to be with formaldehyde solution, while for the loose smut the 

 modified Jensen hot-water treatment is recommended. 



The fiber rot of ginseng and its control, H. H. Whetzel and G. Osner 

 (Spec. Crops, n. ser., 9 {1910), No. 97, pp. J,tl-416, figs. //).— The authors discuss 

 the probable cause, characteristics, and methods of combating this disease, 

 which is supposed to be due to Thelavia basicola, a fungus always found asso- 

 ciated with it. 



It was found that ginseng beds that had been limed were especially subject to 

 this disease, while unlimed beds were more or less free from it, or at least not 

 so severely attacked. In a similar disease of tobacco it was found (E. S. R., 

 20, p. 155) that the fungus, T. basicola, is very sensitive to acids and will not 

 grow in acid soils. The use of acid fertilizers, therefore, proved very beneficial 

 in the case of the tobacco root rot. For this reason, the use of acid phosphate 

 as a means of controlling the disease on the ginseng is recommended. The 

 results of experiments conducted in 1910 by various growers indicate that very 

 beneficial results can be obtained by using from 1,000 to 2,000 lbs. per acre of 

 acid phosphate on ginseng beds infected with fiber rot, aud especially on beds 

 where seed is sown. 



Notes on a fungus found destroying potatoes, T. H. Johnston (Agr. Gas. 

 N. S. Wales, 21 (1910), No. 8, pp. 699-701, pi. 1, fig. I).— A more extended de- 



