Cereal Rust Bulletin
Report No. 1
March 23, 1999
Issued by:
Cereal Disease Laboratory
U.S. Department of Agriculture
Agricultural Research Service
University of Minnesota
1551 Lindig St, St. Paul , MN 55108-6052
(612) 625-6299 FAX (651) 649-5054
Internet: markh@puccini.crl.umn.edu
For the latest cereal rust news from the field, subscribe to the
cereal-rust-survey mail list. To subscribe, send an email message
with the word subscribe in the message body (not subject line) to:
cereal-rust-survey-request@coafes.umn.edu
Reports from this mail list as well as all Cereal Rust Bulletins
are maintained on the CRL web page (http://www.cdl.umn.edu/).
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* Wheat leaf rust is heavier than last year throughout the
southern U.S.
* No wheat stem rust has been found in the U.S. this year, but 20%
oat stem rust severities were reported on volunteer plants in
southern Texas.
* Crown rust is more severe than last year in southern Texas.
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Adequate moisture during the winter has resulted in good cereal
growth throughout most of the southern U.S. small grain growing
area. In southern and central Texas the wheat is in good
condition and near normal crop maturity. In Kansas and Oklahoma
most of the wheat crop is in good condition and there has been
minimal winter injury.
Wheat stem rust.
No wheat stem rust has been found in the U.S. as of March 18.
Wheat leaf rust.
During mid-March, wheat leaf rust severities ranged from traces on
flag leaves to 60% on the lower leaves of cultivars in nursery
plots throughout southern Texas. For example, plots of Custer had
traces of leaf rust, but Karl 92 had 60% severities. Commercial
wheat fields in southern Texas had rust severities ranging from
traces to 20% on the lowest leaves. In southern Texas, rust
increased on the lower leaves when moisture was abundant, but rust
increase farther up the plant has been limited because of recent
dry weather. During November in Oklahoma, leaf rust was severe on
of some of the commonly grown cultivars. However, a hard freeze
in mid to late December, followed by dry conditions through
January and early February, eliminated this leaf rust in many of
these fields. By early March leaf rust was less severe, since
most of the rusted leaves died without the rust spreading to the
younger leaves because of the dry weather in February. However,
with the recent warm and moist conditions, rust will increase and
in some areas be a problem while providing inoculum for the wheat-
growing areas farther north.
In mid-March, wheat leaf rust was increasing in plots of southern
soft red winter wheat cultivars in southern Louisiana. In
February, heavy rainfall in Louisiana did not allow the rust
spores to move up the plants and therefore rust development has
been limited.
Wheat stripe rust.
No wheat stripe rust has been reported in the U.S. as of March 18.
NOTE: Stripe rust is vulnerable to heat and does not survive long
at warm temperatures; therefore, if shipment of collections for
race identification is delayed, their viability will be poor.
Please send wheat and barley stripe rust collections (10 or more
rusted green leaves) as soon as possible after collecting to: Dr.
Roland Line, USDA-ARS, 361 Johnson Hall, Washington State
University, Pullman, WA 99164-6430.
Oat stem rust.
n March 15, twenty percent oat stem rust severities were found on
volunteer plants growing around the edges of a non-cultivated
field 10 miles north of Uvalde,Texas. Last year in the same
field, the oats were destroyed by stem rust. No other oat stem
rust was found in oat fields within the immediate area of these
infections.
Oat crown rust.
During mid-March, crown rust was severe in southern Texas plots
and fields. Foci of sixty-percent severity were common on the
most susceptible cultivars in nursery plots. In southern Texas
oat fields, rust severities ranged from 1 to 20%; on average, rust
development was equal to last year.
In mid-March, crown rust was light in varietal plots in southern
Louisiana.
Barley stem rust.
As of March 18, no stem rust has been reported on barley in the
U.S. this year. Limited amounts of barley are grown commercially
in the southern states. Stem rust on barley rarely occurs in this
area.
Barley leaf rust.
In mid-March, traces of leaf rust were observed on lower leaves in
a few barley plots in southern Texas.
Stripe rust on barley.
No stripe rust on barley has been reported in the U.S. as of March
18.
Rye rusts.
During mid-March, rye leaf rust foci with 10% severities were
found on leaves of winter rye in southern Texas. No rye stem rust
has been reported this year.
Special Note: The latest news on the current cereal rust
situation in the U.S. can be found on our web page
(http://www.cdl.umn.edu/CRB/crbupd.html). If you have information
on the cereal rust situation (or other small grain diseases) that
you would like to share, please email your info to:
cereal-rust-survey@coafes.umn.edu
or David Long (davidl@puccini.crl.umn.edu) and Mark Hughes
(markh@puccini.crl.umn.edu) or if you prefer, call Dave (612-625-
1284). We would like to include your name and email address so
others could contact you. If, however, you prefer not to have
your name or email address appear with the information, we will
omit them. Posting these messages will supplement the Cereal Rust
Bulletins by making cooperators' reports available on the home
page as they come in. Of course, we will continue to incorporate
these reports into the regular issues of the Cereal Rust Bulletin.
Generally, the Cereal Rust Bulletins are compiled every two weeks
during the crop season. We welcome all comments or suggestions on
how we can improve the bulletins or our home page.
Reports on distribution of races of cereal rust fungi are an
important part of our surveys as reported in the Cereal Rust
Bulletin. We regularly collect and test isolates of stem rust
(wheat, oat, and barley), wheat leaf rust, and oat crown rust. We
appreciate receiving collections of these rusts from cooperators
around the U.S. If you would like to contribute, please contact
Dave Long or Mark Hughes, and they will send you a packet of
collection envelopes and forms.