NDSU Extension - Williams County


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Who Would Have Thought Vomitoxin in Western ND - Pine Needle Drop

Published October 19, 2014
Who Would Have Thought Vomitoxin in Western ND - Pine Needle Drop

Scab in wheat

Who Would Have Thought Vomitoxin In Western ND

Several years ago when scab first became a major problem in durum and spring wheat grown in eastern North Dakota, many of us thought it never would be a problem for us in western North Dakota and eastern Montana.  How wrong we were.  This year it has been a major problem for growers of the area.  Scab, technically referred to as Fusarium head blight (FHB), most notably causes shriveled kernels which can be easily separated.  However, there can be a hidden problem not noticeable to the eye.  This is known as deoxynivalenol (DON).  It is also commonly referred to as vomitoxin. The concentrations of vomitoxin in grain are expressed as parts per million (ppm).  One ppm is equivalent to 1 pound in 1 million pounds.  The U.S. Food and Drug Administration (FDA) have expressed vomitoxin advisory levels to provide safe food and feed.  Unlike aflatoxins in corn, vomitoxin is not a known carcinogen.  Furthermore, grain with vomitoxin would have to be ingested in very high amounts to pose a health risk to humans but it can affect flowers in foods and processing performance.  Human food products are restricted to a 1 ppm level established by the FDA.  This level is considered safe for human consumption.  The food industry often sets standards that are more restrictive.  In livestock feed, vomitoxin infected grain causes food refusal and poor weight gain in some livestock.  The FDA advisory level for ruminating beef and feedlot cattle older than four months and for poultry is 10 ppm providing these ingredients don’t exceed 50% of the diet.  Research conducted in North Dakota and Minnesota has suggested growing and finishing cattle can tolerated higher levels (up to 18 ppm) based on research at the Carrington Research Extension Center.  Cleaning the wheat or durum with screening or aspiration often does not adequately remove the scabby or grain infected with vomitoxin.  Best results are obtained with a gravity table but the success is still variable.  Fusarium head blight is caused by a fungus so appropriate personal protective gear such as masks designed to keep out mold spores and grain dust are recommended.  Generally, these masks are either N95 rated which typically have two stages or respirators with HEPA filters.  Vomitoxin usually does not increase when the grain is in storage.  After the grain dries before a moisture level of about 22%, fungal growth and vomitoxin production stops.  High amounts of vomitoxin affected grain do exist in this area.  Much of it is being heavily discounted bringing prices down to feed level.  However, even as feed prices, it must compete with depressed corn prices which is the grain of choice for cattle feeders.  So, it is going to be a challenge to market wheat high in vomitoxin.  More details on vomitoxin in wheat can be found on our web page:  www.ag.ndsu.edu/williamscountyextension.

Pine Needle Drop

Every year there is concern about pine needles turning brown and dropping to the ground.  These needles are located on the inner part of the branch.  Such needle drop varies from year to year, thus causing a great deal of concern to the owner.  When callers describe this situation, I quickly advise them not to worry because this is a natural occurrence.   Though pines and most other conifers are called evergreens, their needles do not stay alive and green forever.  Generally, new needles are produces every spring and summer and last for two to four or more years.  So as the tree grows larger year-by-year, newer needles are always at branch ends and older needles are further back in the crown.  As needles age, they become less efficient at producing food for the tree.  They also become more shaded by newer needles.  For these reasons, old needles finally turn brown and drop off.  This doesn’t hurt the tree because several years’ worth of newer needles are always there to replace the older ones.  Ponderosa pine, which is the most popular kind in this area, usually holds their needles for three to five years.  Do be concerned, however, if your tree is losing needles at the branch tips.  These needles are young and have not out-lived their usefulness.  The culprit for tip needle browning is likely some type of insect or disease.  To help maintain the health of the tree and possibly retain needles for a longer period of time, I suggest a heavy watering before freeze-up.

-Warren Froelich

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