What’s Happening in Organic Ag? May 20-June 4, 2007

1.      Wheat disease update

2.      A global challenge-Wheat Stem Rust

3.      Cover crops for early summer

4.      Growing Canola as an alternative grain crop

5.      Diggin' in: Vegetable garden at Riddle excites elementary students

6.      New MSU Extension Bulletin Focuses on Environmental Farm Practices

7.      2007 farm bill hits first bump

8.      Nonprofit takes root in Ann Arbor

9.      The Day Without Farm Workers

10.  If you seeking Sustainable Bags for your customers or program

11.  The Truth About the Animal ID Plan

12.  A STICKY SITUATION: Honeybee deaths could mean higher prices, more competition for Michigan farmers

13.  Agriculture Events-What is Happening?

14.  Organic Farm Tour in Central Michigan

15.  Accepting Bridge Cards at Your Farmers' Market: EBT Training and Workshop




1. Wheat disease update
Diane Brown-Rytlewski, Plant Pathology, Michigan State University

Editor’s note:
This article was first written for a Michigan audience. However, the information including the Penn State web site has applications for most of the Midwest and Great Lakes states.

Powdery mildew
Powdery mildew is the only wheat foliar disease showing up with any regularity this season, and the amounts of it are quite variable.  On susceptible or highly susceptible varieties, there is a substantial amount of mildew.  With rain and humid weather along with cooler temperatures forecast for the next few days, conditions may be favorable for powdery mildew to come up out of the lower canopy where the temperatures have been cooler and more humid and climb up on the flag leaves and heads.  Lower-risk products registered in Michigan for management of powdery mildew on wheat include: Eco-Mate Armicarb, and Sonata. These products are NOP approved for organic production, however, those who are certified organic should always check with their certifying agency before using a new product.

Fusarium head blight
Wheat in Michigan is flowering in many parts of the state. The most critical period for scab infection is at flowering, although some risk of infection continues until around the soft dough stage.  As of now, across the state, the risk of scab according to the Penn State Model is low.  Parts of the state have been dry, such as around the Montcalm area, and parts of the state have been wetter, such as around Lapeer.  In the Thumb area, temperatures are definitely in the favorable range for infection, but rainfall amounts and relative humidity have been low.  However, rain for fairly long time periods and cooler temperatures that will keep the wheat heads wet for extended periods were forecasted for the past weekend, so risk may have increased over the weekend. 

You can access specific information for a weather station location at the Penn State site http://www.wheatscab.psu.edu/ .  Go to the risk map tool, click on OK. Select the winter wheat model, click on OK.  A map of the U.S. will appear.  Click on Michigan (or your state).  A state map will appear with the weather station locations, and a state-specific commentary box.

Click on one of the station locations.  You will see an indicator bar showing low (green) medium (yellow) or high (red) risk of epidemic conditions for scab.  A graph shows the risk probability for the seven days precious to flowering.  The graph information assumes that the current day is the day of flowering.  The next graph shows temperature and rainfall for the last 7 days.  Click on the arrow next to view model parameters.  That will bring up another bar chart that shows you the temperature in number of hours/day when it was favorable for scab (orange bars) the number of hours of rainfall (purple bars) and the number of hours when both the temperature and the relative humidity were in the favorable range for scab (blue bars).  So, you can determine when conditions were favorable for scab.  Although the model uses temperatures between about 48F and 86F, the most favorable conditions for infection are temperatures between 68-86F, with periods of rainfall longer than 24 hours.

For those of you in Michigan’s Thumb area who want to have a look at the DONCast predictions of vomitoxin levels in wheat across the lake in Ontario, you can access that web site by going to: http://www.weatherinnovations.com/

Go to models and select DONCast.  On the Ontario map, the predicted DON levels for heading on May 31st range from under 1ppm to around 2 ppm.
New stem rust threatens wheat

2. A global challenge-Wheat Stem Rust


May 30, 2007 10:34 AM, By David Bennett
Farm Press Editorial Staff
There are three major wheat rusts — stripe, leaf and stem — and all three can cause serious problems for a crop. In terms of yield loss potential, though, stem rust is king.

At one time, stem rust regularly devastated wheat production around the world. Through use of resistant varieties, the disease has been held in check since the 1950s.

But in 1998, a new race of stem rust appeared in Uganda wheat: Ug99. This finding went rather unnoticed until 1999, when it showed up in Kenyan wheat fields.

“At that point, many international scientists said, ‘This is something we need to check because this new race can overcome many of the effective resistances,’” says David Marshall, research leader with the USDA-ARS in North Carolina. “And that included the resistances that are in the international germ plasm out of CIMMYT (International Maize and Wheat Improvement Centre) in Mexico City. That’s alarming and this rust has become a front-burner issue.”

The new race of rust is a “big concern and justifiably so,” says Rick Cartwright, Arkansas Extension plant pathologist. “Of all the wheat rusts, stem rust has historically been the most dangerous. And it’s back to its bad, old ways. It’s attacking all the wheat varieties in areas of Africa, there’s no resistance and it’s on the move.”

The spread of Ug99 through east Africa “raised a red flag and the USDA, in cooperation with CIMMYT and other international breeding centers, set up a program to identify germ plasm on a worldwide basis based on how it fares — resistant, intermediate, or susceptible — with the new rust race,” says Marshall.

Marshall and colleagues set up a testing program in Kenya. A few years ago, “it was the only place we could screen for this new rust. We didn’t want to bring the pathogen into the United States. So, we’ve had a nursery over there for several years screening U.S. germ plasm for resistance.”

The good news is some resistance was found in U.S. wheat lines. But that resistance isn’t widespread.

“There’s work left to do to breed new resistances into U.S. varieties.”

If east African weather patterns remain constant, the disease should move north and then east. From Uganda and Kenya, Ug99 moved into Ethiopia.

It has now jumped across the sea into Yemen on the Arabian Peninsula and there are unconfirmed reports that it has reached Egypt.

As it travels farther north, it will reach Syria and Turkey. From there it could move into Europe. It will likely also spread east — perhaps as far as China and Russia.

If its spread is natural, the new rust race will probably show up in South America and North America around 2009 or 2010 — about a decade after it was first in Uganda.

“So we have a little time to get things in order before it shows up here,” says Marshall. “We need to make sure we’re not in a vulnerable state when it arrives.”

How frightening is this for the world’s subsistence farmers?

“Very much. Many farmers in Kenya are subsistence growers. They have small plots of land where they grow enough for their family to survive. This rust can be devastating for them and the government knows it.”

Unfortunately, fungicides appear to be no guarantee against the stem rust. Kenyans have had mixed success with treatments.

“I’ve spoken with researchers who have been in Kenya where wheat is grown year-round,” says Gene Milus, University of Arkansas professor and wheat pathologist. “They report that wheat fields had been sprayed three times with Folicur — a good fungicide — and were still wiped out with this race of stem rust. The rust can develop quickly, and if comes in early, can wipe out a crop whether a fungicide is sprayed or not.”

To thwart stem rust, German wheat breeders in the 1930s were able to incorporate a gene from rye — Sr31 — into wheat. The gene was widely adopted and until Ug99 showed up, it worked well.

After Ug99 developed and sources of resistance were being sought, breeders found a gene called. More than half the wheat varieties resistant to Ug99 rust could thank the Sr24 gene.

In 2006, though, a further mutation in Ug99 meant that in addition to being able to overcome Sr31, the rust race was also unbothered by Sr24.

“That means more than half the wheat varieties and breeding lines that were resistant to UG99 are now susceptible to this new race,” says Milus. “There are only a small handful of resistance genes in U.S. wheat varieties that are effective against this new race of stem rust. And there are a few additional resistance genes that are in bad genetic backgrounds or are linked to bad traits.”

All hope isn’t lost, says Milus. “But the outlook isn’t rosy either. Several sources of resistance have been found but these are too few to protect the world’s wheat supply, and some aren’t easy for breeders to utilize.”

Are we years from having a genetic answer to this new rust? “Yes. Because what we’re talking about is replacing most of the current varieties with new ones that are yet to be developed. This is a long haul.”

It isn’t a question of if the new stem rust will arrive in the United States, but when. Fortunately, USDA and its international counterparts appear to understand the urgent need for a solution.

“Money is being made available for research and there’s an international effort to find answers to this,” says Marshall, who is involved with the Global Rust Initiative. “But there’s a lot left to accomplish.”

For more, see http://www.globalrust.org/.

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Vicki Morrone

Organic Vegetable and Crop Outreach Specialist

Michigan State University

C.S. Mott Sustainable Food Systems

303 Natural Resources Bldg.

East Lansing, MI 48824


517-282-3557 (cell)

517-353-3834 (fax)



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