Home / Crops / Corn / Corn Production / Things to consider before choosing one-pass for corn

Things to consider before choosing one-pass for corn

Agriculture.com Staff 07/06/2010 @ 5:21pm

Killing grasses and broadleaf weeds with just one application is popular among growers because it can eliminate overall expenses and save time. Single-pass, soil-applied herbicide programs can work in corn - so long as the proper conditions exist.

Consider the following factors to decide if a one-pass application will achieve effective weed control without compromising yield and profit:

Soil texture. If fields contain coarse- to medium-textured soils, they may be good candidates for one-pass control. Soil-applied herbicides have a greater availability and are more likely to control weeds effectively in these types of soils.

Organic matter. Fields with organic matter content of 4% or less are better candidates for one pass. Locations with higher organic matter content require more herbicide since they contain a greater number of soil microorganisms that can tie up the herbicide and render it less effective. These areas also tend to have more weeds.

Weed levels. Weed infestations that are light to moderate fit the one-pass mold, so long as fields typically don't experience late emergence of ragweeds, waterhemp or cocklebur.

Whether to use one pass, and when to make the application, depends on the level of early season competition from grasses and broadleaf weeds. Most researchers generally agree an early post program is the best timing to achieve one-pass control, but they also acknowledge that you risk application delays that will affect crop yields.

You can usually control weeds with one pass by making preemergence or early post applications, or making applications before weeds reach 2 to 3 inches in height.

Most grass and broadleaf herbicides fall within label recommendations at this stage, and provide a more effective kill because weeds are at a more manageable size. Getting herbicide applications out a little earlier eliminates early season weed competition for moisture and nutrients and helps growers manage risk better.

When it comes to choosing a herbicide program, focus on the broadleaf component of your spray program. Universities rate the performance of grass herbicides pretty close for control of grasses and small-seeded broadleaf weeds like waterhemp, pigweed and lambsquarters. In general, they give a slight edge to the acetochlor herbicides over metolachlor. Make sure that the broadleaf component of your spray program gives you the broadest spectrum of control of broadleaf weeds possible.

Hornet WDG herbicide makes a good tank-mix partner with most grass herbicides because it performs exceptionally well on large-seeded broadleaves like common and giant ragweed, cocklebur, velvetleaf and sunflowers - weeds on which grass herbicides perform poorly. It also boosts the performance of grass herbicides on small-seeded broadleaves.

A one-pass program Dow AgroSciences recommends includes using a soil-applied grass and broadleaf product like Surpass, TopNotch, FulTime, Keystone or Keystone LA herbicide in a tank mix with Hornet WDG herbicide. However, grass products like Harness or Dual Magnum herbicide tank-mixed with Hornet WDG also provide broad-spectrum, one-pass control.

For growers who require a two-pass program, Hornet WDG offers post control of common and giant ragweed, cocklebur, velvetleaf, sunflowers, lambsquarters, marestail and Canada thistle. If waterhemp and pigweed are problem weeds, reduced rates of atrazine, Callisto, Aim or dicamba herbicides may be added with Hornet WDG for the most optimum broad-spectrum control.

Release from Dow AgroSciences

Do you have an agronomy question? Email cheryl.rainford@meredith.com. We'll send some of the most common questions to professionals in the industry and see what they say. Look for answers in upcoming Agro-Connect Ask the Experts columns.

Killing grasses and broadleaf weeds with just one application is popular among growers because it can eliminate overall expenses and save time. Single-pass, soil-applied herbicide programs can work in corn - so long as the proper conditions exist.

CancelPost Comment
MORE FROM AGRICULTURE.COM STAFF more +

Farm and ranch risk management resources By: 07/07/2010 @ 9:10am Government resources USDA Risk Management Agency Download free insurance program and…

Major types of crop insurance policies By: 07/07/2010 @ 9:10am Crop insurance for major field crops comes in two types: yield-based coverage that pays an…

Marketing 101 - Are options the right tool… By: 07/07/2010 @ 9:10am "If you are looking for a low risk way to protect yourself against prices moving either higher or…

MEDIA CENTERmore +
This container should display a .swf file. If not, you may need to upgrade your Flash player.
Weather Trumps Demand