Monday, April 18, 2011

Stripe Rust Update, Pacific Northwest

Winter wheat growth stage ranged from Feekes 3 to 6 across the Pacific Northwest according to Dr. Chen, USDA, Pullman, WA.  The growth stage was mostly related to planting date and less so to location.  Some fields in northern Idaho and eastern Washington reached Feeks 5 and 6, but most fields are in the earlier stage.   

The relative lower-than-normal temperatures since mid February have kept crop growing slowly and also made stripe rust develop slowly.  Otherwise, stripe rust could have exploded.   

However, stripe rust is widely occurring in these regions (more than 70% of wheat fields checked yesterday had stripe rust), plus southern central Washington, western and northeastern Oregon, and southern Idaho, which have been previously reported for stripe rust.  

Some growers have treated with fungicide with their spring herbicide applications. Other areas have seen delays due to rain and wind. As weather conditions are forecast to stay cool over the coming week, many questions still remain.

For fields that have not been sprayed, growers should check for stripe rust and consider spraying fungicides when apply herbicides.

In some early planted fields, barley yellow dwarf was severe last fall and should be expected to continue to be a problem this spring.  Do not mistreat barley yellow dwarf from stripe rust.  BYDV disease does not produce powdery rust dust and yellow symptom starts from leaf tips and moves to the middle of leaves, and more severe along field edges. 

We are asking growers and field consultants to assist us in collecting samples in BYDV infected fields. Contact me by email if you want to help us.

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