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OSU Extension

College of Food, Agricultural, and Environmental Sciences

April 16, 2024 - 9:08am --

Generations ago, Alfalfa was given the nickname “Queen of Forages”, because of its high quality and yield potential when compared to grasses and other legume crops.  It could also be called a queen in that it requires more finesse to produce than grass hay or row crops.  Alfalfa seed isn’t cheap, and a lot of preparation and prior planning go into establishing this valuable crop.  The key factor in maintaining a stand’s viability is weed control.

Many weeds can easily out compete alfalfa for soil nutrient resources, especially in the summer months.  Not only will they thin the stand, but they can reduce the quality of the harvested forage.  While some weeds can actually contribute high protein to the mix, most increase the fiber content.  The high leaf to stem ratio of alfalfa is what gives it the higher quality.  Mature weeds can be the opposite, more stem and less leaf, increasing the acid detergent fiber (ADF) and amylase-treated neutral detergent fiber (aNDF) to raise the fiber and lower relative feed value (RFV).  Some weeds are also nitrate accumulators and high numbers of pigweed or lambsquarter can pose issues when they are stressed.

Spring into weed control action

Weeds germinate throughout the growing season, but spring is the time to initiate control.  You do need to determine what the return potential is of making an herbicide application.  A thin stand will not fill in once the weeds are removed.  If your stand is at least two years old and 25% to 30% are weeds, it is questionable if an application would be of benefit.  This type of stand would be an ideal candidate to interseed a grass if you need tonnage more than highest quality.  If the same stand is 50% or greater weeds, this is a stand that you could also consider interseeding but may be best to transition to another crop.

For established stands that have broken dormancy, you have a few choices for weed control.  You should consult each product’s label as they all have limitations on alfalfa and weed height at application, as well as subsequent crop restrictions and harvest intervals.  If you have a glyphosate tolerant variety you can use glyphosate, or a tank mix of glyphosate and one of others mentioned below.  For grasses in conventional varieties, your best options are Clethodim (Select Max) or Poast.  The 2024 Ohio Weed Control Guide also permits a reduced rate of Gramoxone applied between cuttings, but no more than 5 days after harvest.  For broadleaf control you can consider:

  • Butyrac will kill emerged 2 to 3 inch weeds and can be mixed with Poast to control grasses
  • Chateau EZ (Flumioxazin) on alfalfa that is 6 inches or less, but provides no control of emerged weeds
  • Velpar can be applied to dormant alfalfa or before new growth exceeds 2 inches

Avian Influenza update

Changing gears- there isn’t a lot of new information on the High Pathogenic Avian Influenza (HPAI) at the moment.  From the information gathered, all the infected herds in both Ohio and elsewhere originated from cattle imported from infected Texas herds.  At the time of this article there was a new report from North Carolina of a potential case, but no information on how that issue came to be.  The virus in dairy cattle has been given a new name.   As the name states, HPAI is a serious viral disease of poultry that can result in 75% mortality.  In dairy cattle, the virus isn’t as potent and is now being called Bovine Influenza A Virus (BIAV) to better distinguish it from the virus observed in birds.  As I mentioned in my article a few weeks ago, a strong biosecurity plan is critical for your operation, as is employee hygiene practices.  Animal Health professionals at OSU have been sharing their biosecurity recommendations with producers.  You can access those recommendations at or follow the Buckeye Dairy News Network on its different social media platforms.  For those consumers of dairy products, and fluid milk specifically, it is important to understand that our milk supply is safe.  The pasteurization process inactivates the virus and there is no human health threat to consumers.  Dairy producers should be critical of symptoms within their herd and work with their veterinary professional to help manage their herd health program.

And, lastly, with planting season upon us, most of our county programming is paused until later this summer.  However, we will be hosting a FAMACHA certification program for small ruminant producers on May 31st.  In addition to becoming FAMACHA certified, participants will also learn how to perform fecal egg counts to determine parasite burden, blood sampling techniques, and receive some spring/summer pasture management advice.  The event will be held at the OSU Small Ruminant Research Unit on Fredericksburg Road from 9:00 AM to 3:00 PM.  We are capping registration to the first 20 participants and the cost is $40 each and lunch will be provided.  You can register by calling the OSU Extension office – Wayne County at 330-264-8722.

John Yost is an Extension Educator IV, Agriculture and Natural Resources, at OSU Extension-Wayne County
This article was previously published in The Daily Record.