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Source:
ECO-PB
Results on smut resistance of winter barley
varieties published
Resistance of winter barley against loose and
covered smut has been checked in field
experiments for several years at Dottenfelderhof
near Frankfurt/Germany and the results are now
available on the internet (report in german
only).
A main problem in repetitive seed production of
winter barley according to the guidelines of
organic farming is the risk of an escalation of
infections with covered smut (Ustilago hordei)
and FiBL Germany e.V. in particular loose smut
(U. nuda). The most effective way to avoid these
diseases is the cultivation of resistant
varieties. Therefore, in this research a
screening of resistances in varieties has been
carried out for several years. Concerning loose
smut infection, four geographical origins of
spores differed in their virulence checked by
artificial infection of 15 varieties. 297
varieties were tested with spores originating
from the testing site. Seven commercially
available varieties and 12 recent lines showed
genetically based resistances. Two varieties out
of 15 favourites showed long-term resistance and
furthermore resistance against all four
geographic provenances of spores. Within the
commercially available varieties, cleistogamy
was observed in one variety after two test
cycles and in five varieties after one cycle.
111 commercially available varieties were tested
for resistance against covered smut by means of
artificial infection. Two varieties remained
without symptoms after two test cycles and five
after one cycle. 25 varieties showed a moderate
resistance. Resistance against loose smut did
not correspond with resistance against covered
smut.
Further field trials were conducted to compare
common high yielding varieties with those chosen
particularly with regard to good smut-resistance
or tolerance. Cultivation followed the
guidelines of organic farming. Quality criteria
were grain yield and content of crude protein,
and most important amino acids for animal
nutrition (cystine, lysine, methionine,
threonine, tryptophane). In consideration of all
factors, the results of varieties chosen for
good resistance against loose smut were not
inferior compared to those recommended for
solely high yielding in conventional farming.
Besides resistance against smuts, the degree of
weed suppression was also estimated by means of
measuring leaf areas and lengths of stalks. The
leaf area proved to be the main factor. No
variety achieved an all-embracing combination of
good resistance against loose and covered smut,
high yield including a satisfying content of
essential amino acids and good potential for
suppressing weeds. The availability of
organically produced smut resistant or tolerant
varieties is not satisfying as yet.
The full report can be found under:
http://www.dottenfelderhof-forschung.de/fileadmin/Publikationen/BLE_03_OE_657_LBS_und_IBDF.pdf.
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