Stripe Rust Update November 9th

I would like to pass along the stripe rust update from Dr. Xianming Chen, USDA-ARS scientist in Pullman, WA.

Our October weather conditions have been conducive for stripe rust, so please report any locations that you see with infections. 

The good news is, there was a good, dry break between harvest and planting next year’s winter wheat. While this will reduce the chances of fall stripe rust infections transferring from infected volunteer wheat, it is important to scout susceptible varieties to determine if we have infection and have the potential for overwintering of the fungus.

If you have symptoms in the field that you have questions about, send me a picture. I can often tell easily if it is stripe rust. 

If you know it is stripe rust, send me a picture with the location(s) and varieties so we can keep track of those locations in the spring 2017. An early warning will help us prepare. We usually do not recommend fall application of fungicides, as infected leaves and the fungus often die over the winter.

Cheers,

Juliet

Juliet Marshall, Ph.D.

Associate Professor, Cereals Pathology and Agronomy

Idaho Falls R&E Center
1776 Science Drive Suite 205
Idaho Falls, ID 83402
208-529-8376 office
208-390-4859 cell

http://www.uidaho.edu/extension/cereals/scseidaho

Report from Washington Follows

BYD Aphids are Fly and Strip Rust is Lurking

by Juliet Marshall

Yes, I know most of the acres of winter wheat and winter barley are already planted. If the grain is up and wasn’t treated with an insecticidal seed treatment, it will be vulnerable to aphid infestation and Barley Yellow Dwarf Virus infection. The disease Barley Yellow Dwarf (BYD) can cause significant yield loss depending upon the weather.

Strip Rust on the Move in - Protect Susceptible Varieties

PROTECT susceptible spring wheat with fungicides applied at herbicide timing. A fungicide efficacy chart is attached to this email at this link. Variety ratings of spring wheat to stripe rust in 2014 are available in the 2014 Small Grain Research Report (also on our website). This cool, wet weather will allow rapid spread and infection to occur.

Stripe rust is spreading in western Idaho. Stephens is widely grown in western Idaho and is susceptible to stripe rust. Fields are being sprayed with fungicides but are getting close to the cut-off point for spraying with specific fungicides. Be aware of the PHI (pre-harvest interval) associated with the fungicide being applied - in some cases the PHI restriction may not be when crop is 50% flowering, but before. Know the crop growth stage prior to application to avoid residue issues and off-label applications. 

Stripe Rust Reaches Tetonia

Yesterday afternoon I was at the Tetonia Research Station rating winter wheat for snow mold, and I noticed stripe rust on some lines that were from Washington State’s pathology program. I don’t know the line names / pedigree of infected lines.

Stripe Rust Alert

by Dr. Juliet Marshall

Stripe rust was found (thanks Dr. Oliver Neher for being so observant!) in the Parma area, on the Parma research station in winter wheat in the boot stage. While not yet severe, I fully expect it to be widespread. Be prepared to spray susceptible varieties as it heads east.

Information on variety reactions is available in our small grains report (in variety descriptions and in an appendix table that describes spring wheat reactions). http://www.uidaho.edu/extension/cereals/scseidaho/sgr

Also check the disease page on our website for additional information: http://www.uidaho.edu/extension/cereals/scseidaho/disease

Dr. David Hole, USU, has found stripe rust in a breeding nursery in Logan, UT. Heading has started. Varieties affected included Lewjain, Lucin CL, and an advanced breeding line. Scouting is recommended throughout southern and eastern Idaho.

Please report additional finds to .Marshall, Juliet (jmarshall@uidaho.edu)

Stripe Rust Reported in Eastern Idaho

Stripe rust has been reported in UI Pettit in the Rockford area south west of Blackfoot. 

Stripe rust has been reported in WB936 on west side of Idaho Falls.

Stripe rust has been reported in a spring feed barley (http://www.westbred.com/Products/Northwest/Barley%20Documents/WESTBRED_501.pdf) north of Rupert. The barley was in milk to soft dough. Fungicide application is not recommended for the barley, and in addition the allowable time frame has passed for fungicide application in that field. 

Strip Rust Confirmed in Hazelton

Stripe rust is confirmed in Hazleton, ID, on the soft white winter wheat variety Brundage. So far only in one field, but we will keep monitoring the development. Winter wheat in Jerome area was boot to flowering, but no stripe rust was seen on WB528 and SY Ovation. Root disease (possibly Rhizoctonia) and maybe nematode pressure caused stunting, root damage, yellowing of plants in fields where cereal crops were planted three years in a row.

Stripe Rust Continues to Spread - List of Suseptible Varieties

Stripe rust continues to spread in Brundage and is showing up in other susceptible winter wheat varieties such as Garland hard red winter wheat. Given the current weather, the widespread nature of stripe rust in southern and eastern Idaho, and the forecast for the next week, stripe rust will start to show up in our spring wheat fields, especially the susceptible varieties.

Stripe Rust Now Confirmed in Shelly

Sorry to keep bombarding you with information, but thanks to reports by various consultants in the field I wanted to send out an additional stripe rust update to indicate the current status.

Stripe Rust Report May 5th 2013

Stripe rust has been reported in Northern Idaho by Doug Finkelnburg in the soft white winter variety 'Brundage' on the University of Idaho's research farm in Moscow, ID. Stripe rust is also confirmed in southern Idaho from the Twin Falls / Filer areas (also in Brundage) and in Declo (also in Brundage). If you are growing a susceptible variety, please scout and spray with fungicides as needed. While visiting fields in the Twin Falls area, many fields (approximately 30%) of winter wheat and winter barley were infected with BYDV. Most of the fields of winter wheat were Stephens. What appeared to be a resistant reaction to stripe rust was visible on many of the flag leaves of Stephens. Please don't assume resistance with be maintained in varieties reported as resistant, as changes can and do occur in the race structure of the stripe rust fungi. Please check our website for additional information, pictures, and fungicide efficacy chart.  

Stripe Rust Spotted Near Hazelton May 22nd

I have had the first report of stripe rust in Idaho this year in the Hazleton area on Brundage soft white winter wheat. It was first seen 22 May by the pilot for Red Baron, Clay Seamons, and reported to me by Jared Hobson. Clay sent pictures and yes it is stripe rust. 

Stripe Rust and Frost Reports from Juliet

Two small reports:

Stripe rust was found in Lewiston, UT on Xerpha soft white winter wheat. The pictures sent to me look like the heat in that area is shutting down the infection. In these areas (northern Utah, southern Idaho), winter wheat is in grain fill.  In southeast Idaho, winter wheat is in the boot, flowering, and in early grain fill depending on planting date, variety etc. Dryland winter wheat is suffering greatly from drought.

Strip Rust Update

The latest update on stripe rust:

Oliver Neher, Extension Plant Pathologist for the University of Idaho in Kimberly, reported three fields of Brundage showing stripe rust infection south of the Kimberly exit off of Hwy 84. Upper leaves were infected, indicating the occurrence of a recent spring infection, not an overwintering event. All three fields were sprayed with a fungicide to control the infection.

Stripe Rust Alert: Strip Rust Identified in the Magic Valley 5/28

Stripe rust was observed in the Magic Valley as of 5/28/2012 and confirmed on 5/30/2012 by Dr. Oliver T. Neher, University of Idaho.  Infection was reported on winter wheat ‘Brundage’  planted the second week of September the previous year.

 Resistant varieties should not need fungicide applications, but nevertheless, growers should scout all wheat fields as the prevalent strains of the fungi can change, affecting different varieties.

Stripe Rust Identified on Volunteer Wheat in Burley Area October 26, 2011

Dr. Juliet Marshal identified stripe rust in a field of volunteer wheat right off the highway at the Burley exit.  The volunteer wheat looked like it has been growing for weeks if not a couple of months, and was not heading so it is probably winter wheat.  This means it could host the rust through the winter and be a source of inoculum in the spring, or it will be a source for infection this fall for the local winter wheat.

Watch Out! The Green Bridge for Stripe Rust is in Place!!

Yesterday in the Swan Valley area of Idaho east of Idaho Falls, I was completing some soil sampling for research obligations and observed stripe rust on volunteer wheat that was in the boot stage. I am not sure of the variety of spring wheat. In addition, there is plenty of greenbridge material at lower elevations, and many acres of winter wheat has already been planted throughout the eastern and southern Idaho region. There was a field of winter wheat planted into emerging volunteer in the Ririe area as well. I have concerns about the setting up of a potential over-wintering of stripe rust similar to last year.

Stripe Rust Alert for Fall-planted Winter Wheat

Juliet Marshall, University of Idaho. August 31, 2011

This year is setting up to be a lot like last year. We have a late harvest of spring wheat going, volunteer wheat growing under harvested grain, and some hail damage in winter wheat that has contributed to the “green bridge”. A green bridge is the overlap of different cropping cycles within a year, leading to the constant availability of living, green plants of a given crop.
Given the train wreck with the previous year’s stripe rust epidemic, we need to be vigilant about protecting this year’s grain.

Southern Idaho Strip Rust Update

Much of the stripe rust in winter wheat is starting to shut down, especially in those varieties with high-temperature adult plant resistance (HTAP). We are, at this stage, past the application window for applying fungicides to control stripe rust in winter wheat. In any case, further application in winter wheat would not be economically beneficial.  Most of the winter wheat is in or past the grain fill stage.

In our spring grain, significant damage can still occur depending upon growth stage. The preharvest intervals for most of the fungicides vary from 45 – 30 days, depending upon the fungicide. PLEASE READ AND FOLLOW THE LABEL INSTRUCTIONS. DO NOT spray past the recommended preharvest interval. Spring grains are now in grain fill in the lower elevations, flowering in the Idaho Falls region, and still at stem extension in the upper elevation areas. Some of the spring lines with HTAP are showing higher than expected stripe rust infection (UI Pettit) while HTAP in Alturas, for example, is holding. Those fields that have been sprayed with fungicides at herbicide timing did very well in reducing infection compared to those that were not sprayed, although stripe rust is re-establishing if a second fungicide application was not applied.

In barley, we can find stripe rust but any damage has been minimal. I have yet to see stripe rust in barley in commercial fields at damaging levels. Most barley is past flowering in most of the production areas, except in the higher elevation areas.

Attached is an excel file with ratings of the winter and spring wheat varieties in the extension variety trials in Aberdeen. PLEASE NOTE that the disease pressure at that location is extraordinary. While I included both the seedling and adult reaction of the spring wheat, I did not for the winter wheat, but there are two ratings in the spring/summer and I included the raw data of two replications (untreated with fungicides). The infection type is rated on a 0 to 9 scale, with 0 being immune, 1, 2, 3 resistant, 4,5,6 intermediate, and 7, 8, 9 being susceptible. A rating of 9 means the plant was heavily infected with no chlorosis, and high levels of sporulation. If you would like further information/ clarification on the definitions of infection TYPE, let me know. In addition, there is a rating on the percent leaf area affected in the entire plot. Some varieties have a susceptible reaction, with lower levels of diseased tissue. There was a tremendous amount of necrosis this year, hence the mixed reaction types. For example, one variety may have a rating of 5/8 and percent 30/5, meaning that 30 % of the plot had an infection type about 5 (intermediate resistance with quite a bit of necrosis but sporulating still) and 5 % of the plants in the plot were showing extensive sporulation with an infection type of 8, with a little chlorosis.

Please let me know if you have additional questions.

Juliet

Juliet Marshall
Associate Professor, Cereals Pathology and Agronomy

Idaho Falls R&E Center
1776 Science Drive Suite 205
Idaho Falls, ID 83402
208-529-8376 office
208-390-4859 cell

http://www.cals.uidaho.edu/scseidaho/

Cereal Sentinel #157 is On-Line

Dr. Bradford Browns, of the Parma R&E Center has his most recent issue of the Cereal Sentinel on line.  This issues includes articles on:

Stripe Rust Ramblings
No-till Wheat Gaining Foothold
Extension Educator Leaving
SW Idaho Extension Cereals Website

Cereal Sentinel #157

Stripe Rust Identified is the Aberdeen Area

Stripe rust has been found in winter barley in the Aberdeen area. This is not the same strain of stripe rust causing the disease in wheat. None of the currently grown varieties of barley have resistance to the stripe rust fungus (that I am aware of.) I definitely advise incorporating fungicides at herbicide timing. Stripe rust continues to advance in winter and spring wheat. It is getting close to the time limit for spraying winter wheat with fungicides, which may be before flowering for some fungicides or up to 50% flowering depending upon the fungicide. READ AND FOLLOW THE LABEL directions.



Update by 
Juliet Marshall
Associate Professor, Cereals Pathology and Agronomy

Idaho Falls R&E Center
1776 Science Drive Suite 205
Idaho Falls, ID 83402
208-529-8376 office
208-390-4859 cell

http://www.cals.uidaho.edu/scseidaho/