Forage Journal

October 24, 2015 02:51 AM

Zeolite Might Control Aphanomyces in Alfalfa

A naturally occurring mineral is showing new promise for commercial and organic alfalfa growers.

Alfalfa seeds are vulnerable to several soil-borne diseases, so most seeds are coated with a mefenoxam fungicidal treatment, which is ineffective against the pathogen causing Aphanomyces root rot (ARR) in Midwestern soils. 

Deborah Samac, a plant pathologist at the USDA–Agricultural Research Service’s Plant Science Research Unit in St. Paul, Minn., is researching zeolite, a mineral from degraded volcanic rock, to see if it could lend it’s antifungal activity to alfalfa seedlings as an organic soil treatment. So far, results show a zeolite coating was as effective as mefanoxamin in protecting seeds from most soil pathogens and ARR. It did not inhibit production of healthy roots or soil microbes. For more information, visit

An Old Forage Gains Research Attention

A forgotten forage grass imported from Europe in the 1800s could be making a comeback in the Upper Midwest. Hidden Valley, a meadow fescue grass, has been released by USDA–Agricultural Research Service (ARS) scientists in Madison, Wis.

Discovered on a farmer’s shaded hilltop in a long-time pasture that had never been seeded with commercial forages, it gradually spread from the hilltop grove into gullies and open areas. Cattle thrived on the forage. The farmer began consulting with USDA–ARS plant geneticist Michael Casler and his colleagues at the U.S. Dairy Forage Research Center to identify the grass. 

Since then, the team has spent more than a decade evaluating the grass. It produces a 9% lower yield than orchardgrass and tall fescue, but has a 9% higher rate of neutral detergent fiber digestibility. Research also shows it has adapted to the Upper Mississippi River Basin by developing several desirable traits, such as drought tolerance, and will survive freezing temperatures and repeated grazing. For additional information, visit

Spray Option for Fescue Toxicosis

Dow AgriSciences says an early spring application of Chaparral herbicide can control broadleaf weeds and help reduce tall fescue seedheads, reducing the risk of fescue toxicosis for livestock. The seedhead is where the alkaloids produced by the endophyte concentrate (at a rate five times higher than in leaves or stems). Reducing or eliminating seedheads can help decrease the incidence and severity of fescue toxicosis. 

Toxins in tall fescue peak when the seedhead is most palatable, generally mid- to late-June. However, the period of highest concentration does not coincide with visible symptoms of fescue toxicosis because of the toxins’ residual effects. Animals consume high concentrations in the spring and then suffer from heat stress when the effects are exacerbated by hot summer temperatures. Applying Chaparral at green-up in early spring when tall fescue plants reach about 6" prevents most tall fescue plants from producing seedheads and keeps plants in a vegetative state.

Chaparral herbicide is labeled to control winter annual weeds and other early season broadleaves, such as buttercup; poison hemlock; biennial musk, bull and plumeless thistle; wild carrot; and common mullein. This earlier application might intensify Chaparral’s effect on certain grass species, including tall fescue, such as grass yellowing, which can last at least a couple of weeks. 

For more information, contact your local representative or visit

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