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Can Corn See Weeds?

Don’t Fall Victim to the Far-Red Effect

Syngenta is investing in research that will elevate the importance of using a pre-emerge herbicide in corn to eliminate early weed competition. Scientists are investigating the "far-red effect," a destructive wavelength of light that robs optimum corn yield potential when weeds are allowed to compete with the crop.

Data are being evaluated to analyze the impact of the far-red effect on kernel count, days to silking, plant height and other measurements.

The photo below, taken by Dr. Clarence Swanton, weed scientist at the University of Guelph, Ontario, shows that ears of corn are more consistent, kernel count is higher and yield is greater when corn grows in weed-free conditions.

  • When weeds were removed at V3, there was a yield reduction of 4 percent and a kernel count reduction of 6 percent.
  • When weeds were removed at V6, there was a yield reduction of 20 percent and a kernel count reduction of 13 percent.

Bottom line: Manage the far-red effect and maximize corn yield potential by eliminating weed competition early in the season

Lumax® EZ and Lexar® EZ corn herbicides control broadleaf weeds and grasses before they can compete with the corn crop thus eliminating the far-red effect. Both of these products are powered by Callisto Plant Technology®, which delivers the longest-lasting residual broadleaf weed control in corn. Using inferior pre-emergence herbicides can compromise early-season weed control thus allowing the far-red effect to reduce corn yield potential.

The Far-Red Effect Defined

When corn grows in weedy conditions, far-red light is reflected from weeds onto the corn plants. Corn detects this light and adopts a shade-avoidance growth strategy in response. This natural defense mechanism causes the plant to grow taller stalks and wider leaves to better compete for light, but the energy this takes leaves fewer resources for root development compromising how well the corn plant is able to compete for light, moisture and nutrients resulting in irreversible loss of yield potential.


Carroll Moseley Audio Clip

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Dr. Swanton discussing the Far-Red Effect.



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