Wheat Rusts as a Potential Problem in

Norwegian Wheat Cultivation

Jon Arne Dieseth Graminor AS

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

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

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.

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

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

Expected increase in mean temperature by year 2100

Norwegian Environment Agency DN-utredning 2006-2

Monthly mean temperature in Oslo compared to some other European capitals

January -­‐4,3 4,9 10,2 4,9 9,0February -­‐4,0 4,5 10,0 5,4 9,5March -­‐0,2 2,7 8,2 5,0 8,6April 4,5 1,6 5,4 4,4 6,3May 10,8 0,3 2,5 3,5 4,0June 15,2 -­‐0,4 1,0 1,9 2,3July 16,4 0,5 2,2 2,8 3,6August 15,2 1,5 3,4 3,7 4,8September 10,8 2,3 5,1 3,7 5,8October 6,3 2,8 6,1 3,4 6,2November 0,7 4,2 8,0 4,0 7,2December -­‐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)

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

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

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

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

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

Thank you for your attention !