Are those weeds worthy of treatment?

decrease font size  Resize text   increase font size       Printer-friendly version of this article Printer-friendly version of this article

Kevin Bradley, University of Missouri, has received a few calls lately from producers asking what density of winter annual weeds justifies treatment in winter wheat. While there’s not a lot of information out there in the weed science literature on this subject, Bradley presents a few highlights of what he could find for some of the most common weeds that infest wheat in Missouri.

Common Chickweed. Most of the available research on common chickweed indicates that this winter annual will cause wheat yield reductions when this weed is present at densities of at least 30 plants per square meter and higher. In research conducted throughout Missouri, wheat yields were reduced by as much as 28% with common chickweed densities of 169 plants per square meter.  

Cheat/Downy Brome. In fields with cheat and downy brome infestations, herbicide applications are almost always warranted, especially when these grasses emerge at or within the first few weeks after wheat planting. Researchers in Oklahoma have observed a 49% reduction in wheat yield due to cheat infestations of 86 plants per square meter (Koscelny and Peeper, 1997). Similarly, wheat yield reductions greater than 60% have been reported in fields with 200 downy brome plants per square meter (Blackshaw 1993). 

Henbit/Purple Deadnettle. Henbit is one of those weeds that may not compete as effectively with wheat as some of the other winter annuals like chickweed, cheat, and downy brome, but still may cause yield reductions when present at high densities. Bradley would put purple deadnettle in this same category, but can’t find any data to support that statement. Research conducted in several locations in Missouri has revealed that henbit densities of 18 plants per square meter will not cause wheat yield reductions but henbit densities of 82 plants per square meter can reduce yields by as much as 13%. Another thing to consider before making a decision to treat henbit and purple deadnettle especially is their stage of growth. If these species are blooming at the time of application, they have already entered into their natural state of senescence and their sole goal at this point is to complete seed production. So while you may reduce seed production in these species, chances are these weeds are not going to be competitive enough with wheat to make it an economically justifiable treatment.

Wild Garlic and Wild Onion. Although wild garlic is not considered much of a competitor with wheat, control of wild garlic in wheat is an absolute necessity because of the dockage that will occur at the grain elevator. So, there really can’t be any allowance for this species in wheat.

Buyers Guide

Doyle Equipment Manufacturing Co.
Doyle Equipment Manufacturing prides themselves as being “The King of the Rotary’s” with their Direct Drive Rotary Blend Systems. With numerous setup possibilities and sizes, ranging from a  more...
A.J. Sackett Sons & Company
Sackett Blend Towers feature the H.I.M, High Intensity Mixer, the next generation of blending and coating technology which supports Precision Fertilizer Blending®. Its unique design allows  more...
R&R Manufacturing Inc.
The R&R Minuteman Blend System is the original proven performer. Fast, precise blending with a compact foot print. Significantly lower horsepower requirement. Low inload height with large  more...
Junge Control Inc.
Junge Control Inc. creates state-of-the-art product blending and measuring solutions that allow you to totally maximize operating efficiency with amazing accuracy and repeatability, superior  more...
Yargus Manufacturing
The flagship blending system for the Layco product line is the fully automated Layco DW System™. The advanced technology of the Layco DW (Declining Weight) system results in a blending  more...
Yargus Manufacturing
The LAYCOTE™ Automated Coating System provides a new level of coating accuracy for a stand-alone coating system or for coating (impregnating) in an automated blending system. The unique  more...
John Deere
The DN345 Drawn Dry Spreader can carry more than 12 tons of fertilizer and 17.5 tons of lime. Designed to operate at field speeds up to 20 MPH with full loads and the G4 spreader uniformly  more...
Force Unlimited
The Pro-Force is a multi-purpose spreader with a wider apron and steeper sides. Our Pro-Force has the most aggressive 30” spinner on the market, and is capable of spreading higher rates of  more...
BBI Spreaders
MagnaSpread 2 & MagnaSpread 3 — With BBI’s patented multi-bin technology, these spreaders operate multiple hoppers guided by independent, variable-rate technology. These models are built on  more...

Comments (0) Leave a comment 

e-Mail (required)


characters left


YOUR BEST HARVEST IS NOW WITHIN REACH J&M introduces their patented line of X-tended Reach grain carts, featuring a frontfolding single ... Read More

View all Products in this segment

View All Buyers Guides

Feedback Form
Feedback Form