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Filipowicz Farm

Well-Known Member
Aug 21, 2003
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Found this article in our new edition of Michigan Farm News.


"Be alert for hoary

alyssum in pastures

As if horse owners don't have enough to

think about, with increasing prices for feed,

fuel, products and services, fly season in full

swing, and continuing challenges with land

use and access to trails, they can add awareness

of hoary alyssum, a weed that is poisonous

to horses, to their list of concerns.

Hoary alyssum is found across the northeastern

and north central United States and

Canada. A member of the mustard family, it

produces small white flowers and can grow 1

to 3 feet tall. Grayish green "hairs" cover the

stems, leaves and seed pods. lt is well-adapted

to dry conditions and grows in droughtstressed

and overgrazed pastures.

"We have had cases of hoary alyssum toxicity

in horses already this yeal as a result of

hay cut last year," said Karen Waite, Michigan

State University (MSU) Extension equine


Horse owners need to learn to identify hoary

alyssum and the signs of its toxicity in their

animals. Waite warns that those who may

feel that they don't have to worry because

they feed supplemental hay and grain should

think again: horses on pasture, even if they

receive hay and grain, may also graze on hoary

alyssum if they find it in their fields. Though

it is not preferred horse forage, horses will

nibble on it when other plants are not growing

because of overgrazing or drought.

Toxicity symptoms rn horses range from

depression to stocking up (swelling in the

lower legs), fever and diarrhea. Some horses

are extremely susceptible to the toxin, and

consumption of hoary alyssum may prove

fatal. As little as 10 percent hoary alyssum

in one bale of hay may cause problems for

some horses.

Minimizing problems with hoary alyssum

and other weeds begins with good pasture establishment

and controlled grazing. When the

weed is found in an established pasture, the

herbicides that are labeled for its control will

also affect forage legumes. lf drought conditions

have left few other plants in the pasture,

removing the animals for the remainder of the

growing season is an option.

Hay should also be thoroughly examined for

presence of hoary alyssum.

MSU and MSU Extension offer a number of

drought-related resources. For more information

about hoary alyssum, horse owners may

refer to a fact sheetitled "Toxicity, ldentification

and Control of Hoary Alyssum in Forages.

" lt can be found online or is available at

any MSU Extension county office.

lmages and other information about hoary

alyssum can also be found on the MSU Diagnostic

Services weed and plant identification

Web site at http ://pestid. anr. msu. ed uArVeedsPlantldentif

ication/Hoaryalyssum/tabid/1 39/


Source: MSU

[SIZE=12pt] [/SIZE]


Well-Known Member
Nov 30, 2002
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Thank you for this information.

Is there a photo of this plant?


Filipowicz Farm

Well-Known Member
Aug 21, 2003
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Down at the bottom of the article is the website with photos

http ://pestid. anr. msu. ed uArVeedsPlantldentification/Hoaryalyssum/tabid/1 39/


Well-Known Member
Dec 4, 2002
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Amery, Wisconsin