656 
Journal of Agricultural Research 
Vol. XXIV. Na $ 
longer periods of exposure to cooler water. Muller and Molz (pj), as 
well as Lind and Ravn (< 9 i), found hot-air treatment worse than 
useless for stripe, as it tended to increase the proportion of diseased 
plants; Atanasoff and Johnson (j), on the other hand, found that such 
treatment markedly reduced the disease without materially injuring the 
seed. As the disinfection of barley seed usually involves a number of 
diseases, the choice of any particular treatment often is contingent on its 
effectiveness in controlling smut, netblotch, spotblotch, and the bacterial 
blight as well as stripe. 
Owing to the successful control of stripe by seed treatment, not much 
attention has been devoted to other methods of combating the disease. 
The various reports already mentioned, of the occurrence of an ascigerous 
stage, and the statement by Paxton that 16-year old herbarium speci¬ 
mens of cultivated barley affected with Helminthosporium gramineum, 
when placed in a moist chamber, produced conidiophores and viable 
conidia from the dormant mycelium, suggest the possible value of meas¬ 
ures involving sanitation. Indeed, Frgmk (^j), Weiss (157), and later 
Jaczevski (66) recommended rotation of crops, though perhaps more 
on general principles than because of possible experimental evidence or 
knowledge of the presence in fields of an overwintering stage playing an 
important part in establishing the parasite on successive crops. Fer- 
raris (40) recommended burning the stubble in addition to seed disin¬ 
fection. The removal and destruction of diseased plants found effective 
in Scotland (134) would obviously constitute a method of eradication 
too laborious to be seriously considered in the United States. The 
observations of various investigators, notably of Hori (63) and of Lind 
and Ravn (81 ), show that the proportion of diseased plants is increased 
when the seed germinates in soil at a low temperature. Muller and 
Molz (pj), however, did not find late sowing in a warmer seedbed advis¬ 
able; for, although less disease developed, the delay brought about a 
decrease in the yield. 
Von Post (hi) observed considerable differences in susceptibility to 
stripe between varieties of barley. Ravn (113) found the six-rowed 
varieties as well as the erectum types more heavily attacked, in general, 
by Helminthosporium gramineum than the nutans types, a condition 
exactly the opposite of that he found to obtain with reference to attack 
by H, teres. Kiessling (76), while unable to confirm Ravn's findings 
regarding the comparative susceptibility of the nodding and the erect 
types, noted pronounced differences in the proportions of diseased 
plants present in the stands of different varieties. It is worthy of note 
that some of KiessHng’s strains, representing genetically pure lines, 
manifested with fair consistency moderate susceptibility, while other 
pure lines exhibited a high degree of resistance. This author urged, 
very justifiably, that the plant breeder ascertain the measure of resistance 
to stripe inherent in any varieties of barley with which he may be dealing 
and reject those lines showing marked susceptibility. 
HELMINTHOSPORIUM TERES SACC.—PYRENOPHORA TERES 
(DIEDICKE) 
Helminthosporium kordei Eidam 1891, in Der Landwirt, Bd. 27, p. 509. 
Pleospora teres Died. 1903, in Centralbl. f. Bakt. Abt. 2, Bd. 2, no. 2, p. 52-59. 
The binomial Helminthosporium teres was applied by Saccardo (126^ 
pi. 833) to a fungus collected on leaves of barley near Padua, March, 
1881, and figured in the “Fungi Italici’* as having 3-septate conidio- 
