Wheat Weed Control Starts Early.

DR. BOB SCOTT

FAYETTEVILLE, ARKANSAS

I am hearing rumors that a few growers are planting a little wheat this year.  Acres have been quite down in the mid-south for the past several years compared to how they once were.  In terms of weed control for wheat, there have been only a few changes recently to be aware of.

Ryegrass continues to be one of the most problematic weeds in wheat production.  There is a lot of resistance to most of our post herbicide options for ryegrass control in wheat, these include: PowerFlex, Osprey and Axial Bold, among others.  Of all these, I probably still have the most luck with Axial Bold, however, these populations of ryegrass vary greatly from location to location.  This is a good place as any to stick in a reminder that ryegrass seed is not long lived in the soil seedbank.  So, if you make efforts this fall to control ryegrass around the edges of your fields and not let ryegrass go to seed, it will pay immediate benefits the following fall with reduced populations and spread of this weed.

The best option we have now for ryegrass control in wheat is a delayed pre application of Zidua or Anthem Flex.  Delayed pre’s are applied after planting, but not until the wheat has received rain, irrigation or imbibed water for germination (planted into moisture).  Unfortunately, this waiting process can also allow some ryegrass to germinated and be “missed” depending on weather and timing.  This is a good time to mention that there are no ryegrass control options labeled for oats.  I mention this only because this is an annual call that I get.

Numerous broadleaf weeds can inhibit wheat early and cause delayed stand establishment and if thick enough hurt wheat yields.  A few broadleaves can interfere with harvest and cause significant loss. There are numerous control options available for most of these weeds. I will not get into all those here, but if you would like a run down of them the wheat section of the Arkansas Wheat Production Handbook has been updated and can be found here: MP404 page. 

One broadleaf weed to watch out for is mayweed.  There have now been numerous populations identified around Arkansas that are resistant to the ALS or Group 2 herbicide options like Harmony Extra.  In these cases, Quelex is our best option for equivalent control.

You can also find weed control information for wheat and fall wildlife food plots in the MP44 at this link: Recommended Chemicals for Weed and Brush Control - MP44.  

DR. BOB SCOTT

UNIVERSITY OF ARKANSAS