Sept. 1,1924 
Stripe Rust 
225 
included in their experimental study 
of varietal resistance to both Puccinia 
glumarum and P. graminis, Garton's 
Early Cone and Percival’s Blue Cone 
proved resistant to both rusts. They 
found that certain varieties, seemingly 
rust-resistant, were merely rust-escap¬ 
ing because of their more rapid growth 
and maturity. The general adoption 
of such spring wheats undoubtedly 
would serve to reduce the danger of loss 
from stripe rust, but it is hardly proba¬ 
ble that this would apply to winter 
varieties for the reason that the occa¬ 
sional presence of hibernating mycelium 
would make possible early and destruc¬ 
tive outbreaks of stripe rust. 
As in Europe, so also in the United 
States, wheat varieties differ markedly 
in their susceptibility to stripe rust. 
Moreover, varieties differ in suscepti¬ 
bility to infection both in the heads and 
in the leaves. Observations made by 
writers in 1915 at Corvallis, Oreg., on 
Chul wheat showed this variety heavily 
infected in the floral parts, especially 
the glumes, while but slight infection 
was noted on the blades and sheaths. 
Kernels from these infected heads were 
later examined microscopically and 
found to contain abundant internal in¬ 
fections. A number of other wheat 
varieties growing alongside showed no 
infection on the floral parts but a con¬ 
siderable amount of it on the leaves. 
One of the writers (Hungerford) has 
made similar observations. An excerpt 
from a summary of notes taken by him 
on an inspection trip made in 1916 pre¬ 
sents the following interesting data on 
the subject of varietal resistance to 
stripe rust: “There seemed to be not 
only a vast amount of difference in 
the susceptibility of the various varie¬ 
ties of wheat to stripe rust but also 
there was a difference in the amount 
of infection appearing upon the glumes 
and on the kernels. Chul wheat did 
not seem to be especially heavily in¬ 
fected on the leaves, but was, in every 
case where noted, infected in the glumes 
to a marked degree.” 
During the first year (1915) stripe 
rust was observed in the United States, 
marked varietal differences in suscepti¬ 
bility to leaf infection were noted. 5 
In a series of wheat varieties grow¬ 
ing in adjacent twentieth-acre plats at 
Moro, Oreg., the leaves of Dale (C. I. 
No. 4155) were the most heavily in¬ 
fected, averaging about 85 per cent 
infection. Hybrid 123 (C. I. No. 
4511), Baart (C. I. No. 1697), Little 
Club (C. I. No. 4066), Purplestraw 
(C. I. No. 1915), Turkey selection (C. I. 
No. 2998-1), and Beloglina (C. I. No. 
2239) also were rather heavily infected, 
the infection ranging from about 75 
per cent to 40 per cent in the order 
given. The other wheat varieties in 
the series all showed infections vary¬ 
ing from about 30 per cent to a mere 
trace. During the same year (1915) 
Little Club showed about 65 per cent 
of infection at Moscow, Idaho, while 
other varieties there showed only slight 
infections or none at all. Subsequent 
observations and experiments by Hun¬ 
gerford and Owens {12) have shown 
more fully the relative susceptibility of 
different wheat varieties to stripe rust, 
SUMMARY 
(1) Collections of Puccinia glumarum 
were made in North America by various 
American botanists during the 90’s and 
the early years of the present century ^ 
These collections were distributed 
under names other than P. glumarum . 
(2) Puccinia glumarum was found 
and recognized in the United States 
by the late F. K0lpin Ravn of Copen¬ 
hagen, Denmark, in May, 1915. 
(3) The common name, stripe rust, 
is proposed in lieu of yellow rust or 
golden rust as a common name for the 
disease caused by Puccinia glumarum . 
This accords with the Italian name, 
ruggine striata del grano. 
(4) Puccinia glumarum is now known 
to occur from British Columbia to 
Mexico and eastward to 103° W. longi¬ 
tude. It has been found in all of the 
Pacific and Intermountain States ex¬ 
cept Nevada and New Mexico. 
(5) Stripe rust is a disease of con¬ 
siderable economic importance in Great 
Britain, Northern and Central Europe, 
North Africa, Japan, and India. Its 
destructiveness in the United States 
would undoubtedly be fully as serious 
as that experienced in “rust years” 
in Europe should it become established 
in the soft red winter-wheat areas east 
of the Mississippi River. 
(6) Puccinia glumarum is now known 
to occur in nature on 34 wild grasses 
common to the United States in addi¬ 
tion «to the cultivated hosts, wheat, 
barley, rye, spelt, and emmer. 
(7) Certain varieties of wheat ap¬ 
parently are much more subject to 
glume and kernel infection than others. 
All susceptible varieties show general 
leaf infection. 
(8) An aecial host for Puccinia 
glumarum has not yet been discovered. 
(9) The dimensions, particularly the 
length, of urediniospores produced on 
the leaves vary according to location 
on the leaf. Those occurring in ure- 
« These early observation were mad 3 jointly by two of the writers (Humphrey and Johnson) and 
Dr. F. K01pin Ravn. 
