This document discusses wheat rust diseases as a potential problem for Norwegian wheat cultivation due to forecasted climate changes. Currently, wheat rusts are not a major issue but stripe rust occasionally causes local outbreaks. However, predicted higher winter temperatures could allow more rust inoculum to survive winters. Milder autumns and springs along with warmer, wetter summers may also promote faster rust development. As a result, the risks of future rust epidemics are expected to increase. The document recommends strategies like growing winter wheat varieties with good rust resistance and breeding for horizontal resistance to control potential rust problems.

1. Wheat Rusts as
a Potential Problem in
Norwegian Wheat Cultivation
Jon Arne Dieseth
Graminor AS

2. Important wheat diseases in Norway
n Leaf blotch diseases
n Stagonospora nodorun most important
n Severity depends on amount and pattern of rainfall
n Fusarium head blight
n Fusarium graminearum most important
n Severe effects on yield and quality in seasons with
rainfall at the time of heading and flowering
n Powdery mildew
n Most severe in relatively dry seasons

3. Wheat rusts in Norway
n Stripe rust
n Occasionally local outbreak
n Last epidemic in 1987
n Leaf rust
n Often seen in southern areas
late in the season
n Stem rust
n Rare
n Last epidemic in 1951

4. Wheat rusts in Norway
n Winter wheat varieties with relatively good
resistance leave little inoculum in the field after the
winter
n It appears like the rust inoculums do not survive the
cold Norwegian winter on the winter wheat crop.
n Alternative host
(wild barberry)
is very rare.

5. Observed climatic changes in
Southeast Norway (Oslo)
Monthly mean temperature in the two coldest months
y = 0,050x-103
R² = 0,0668
y = 0,053x-109
R² = 0,066
-12.0
-10.0
-8.0
-6.0
-4.0
-2.0
0.0
2.0
4.0
January
February

6. Observed climatic changes in
Southeast Norway (Oslo)
Monthly mean temperature in the two hottest months
y = 0,036x - 53
R² = 0,1586
y = 0,030x - 43
R² = 0,0801
10.0
11.0
12.0
13.0
14.0
15.0
16.0
17.0
18.0
19.0
20.0
21.0
22.0
July
August

7. Expected increase in mean
temperature by year 2100
Norwegian Environment Agency
DN-utredning 2006-2

8. Monthly mean temperature in Oslo compared
to some other European capitals
January -­‐4,3 4,9 10,2 4,9 9,0
February -­‐4,0 4,5 10,0 5,4 9,5
March -­‐0,2 2,7 8,2 5,0 8,6
April 4,5 1,6 5,4 4,4 6,3
May 10,8 0,3 2,5 3,5 4,0
June 15,2 -­‐0,4 1,0 1,9 2,3
July 16,4 0,5 2,2 2,8 3,6
August 15,2 1,5 3,4 3,7 4,8
September 10,8 2,3 5,1 3,7 5,8
October 6,3 2,8 6,1 3,4 6,2
November 0,7 4,2 8,0 4,0 7,2
December -­‐3,1 5,2 10,0 5,1 8,8
Month
Monthly
mean
temp.
(°C)
in
Oslo
Differences
in
monthly
mean
temperature
compared
to
Oslo
Copen-­‐
hagen London Berlin Paris
(Met. data from yr.no)

9. Clima&c
changes
Effects
on
the
wheat
rust
Higher
mean
winter
tempereature
More
inoculum
Few
very
cold
days
More
inoculum
Shorter
period
with
snow
cover
?
Mild
and
wet
autumn
and
spring
?
Warmer
summer
months
Faster
development
More
summer
rain
in
periods
?
Expected effects of climatic changes
on the rust situation in Norway

10. n “Better” conditions for
winter survival of inoculums
n Diseased fields closer
to Norway
n Faster and more severe
disease development in
the growth season
n Higher risk for rust epidemic
n Stripe rust
Effects of climatic changes on the
rust situation in Norway

11. Strategies to avoid future wheat
rust epidemics in Norway
n Winter wheat varieties with good rust resistance
n Reduce the amount of spring inoculums
n Fungicide application in the autumn to eradicate
rust inoculums
n Rust resistant spring wheat varieties
n Difficult to breed for resistance to diseases that are
not present
n Marker assisted selection

12. Marker assisted selection for horizontal
resistance to powdery mildew (and rust)
in Norway
QTL %
Powdery
mildew
%
Leaf rust
%
Stripe rust
None 79 91 77
Lr34/Yr18/Pm38 39 10 39
Lr46/Yr29/Pm39 39 26 49
3A-QTL 58 83 51
Lr34+Lr46 36 4 29
Lr34+Lr46+3A 14 2 24
Avocet 83 100 97
Saar 5 1 8
Lillemo 2008

13. Summary
n Rust diseases on wheat do, for the time being, not
create serious damage in Norwegian wheat fields.
n Wheat rusts, especially stripe rust, is a potential treat.
n Forecasted climatic changes might enhance winter
survival and summer development of wheat rusts.
n Problems with rust diseases are likely to increase.
n Resistant winter wheat varieties will be important to
reduce spring inoculums.
n Breeding for horizontal resistance to powdery mildew,
introducing genes with effect also on rust
development, will be important for rust control

14. Thank you for
your attention !