Annual Progress Report on Malting Barley Research March, 2007

small grains pathology input to this project involves the oversight of inoculum
preparation during the winter and spring, assisting with summer plot maintenance
including the operation of the mist-irrigation system, and spray applications of inoculum
during the summer field season.
In the 2006 field season a total of 14,350 rows were screened in breeding nurseries.
The number of field rows evaluated was much the same as in the previous two years.
Field nurseries were conducted at three locations; St Paul with 6,800 rows, Morris with
800 rows and Crookston with 6,750 rows. Nurseries at all three locations were primarily
inoculated and mist-irrigated to promote disease development, although we also
established dryland (without irrigation) nurseries at both St Paul and Crookston to
provide additional screening under weather conditions which more closely resemble
those of commercial crops. In 2006 approximately 4000 liters of macroconidial
inoculum (800,000 macroconidia ml -1 ) was produced in our lab and used by five
separate research programs (for barley, wheat and oat research).
Greenhouse Screening Program: During the fall, winter, and spring seasons
greenhouse tests for resistance to Fusarium head blight are conducted in the
greenhouse. Testing of approximately 250 pots of barley was completed in 2006. The
inoculation of barley plants in the greenhouse is conducted using an airbrush sprayer to
deliver macroconidial inoculum to one face of the barley spike. Point inoculations, as
used widely in screening wheat for resistance to FHB, do not differentiate between
resistance and susceptible barley varieties. This spray inoculation technique has
proven useful to detect QTL associated with reaction to deoxynivalenol accumulation in
barley.
Research on Foliar Diseases – Methodology and Results
This program provides support to the barley breeding program as part of ongoing
breeding efforts to develop improved germplasm with improved disease resistance.
Screening breeding germplasm for resistance to kernel discoloration, leaf rust, loose
smut, net blotch, powdery mildew, and spot blotch are conducted on an ongoing basis
with the barley breeding program.
In 2006 evaluations were conducted to identify resistant germplasm in breeding
populations following natural infections of leaf spot diseases at the Northwest Research
and Outreach Center, Crookston and the West Central Research and Outreach Center,
Morris.
In 2006, we established a net blotch nursery of approximately 600 rows at Stephen.
However, due to the extremely dry conditions in 2006, little disease development was
observed. Nevertheless, straw infected with the net blotch pathogen was collected by
for inoculation of the nursery in 2007. Despite two disappointing years (the 2005 trial
was lost to flooding) we remain confident that future screening nurseries in Stephen will
be successful. The only two nurseries we have lost in over ten years have been these
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