As a business owner, I tend to focus on the bottom line.  The bottom line here is that farmers need more weapons in the war against resistance weeds.

Weeds are more than unsightly.  They’re more than a nuisance…  They’re costly!  Weeds are yield robbers, meaning there is less crop (i.e. food) produced come harvest time.  Yield losses can accumulate very rapidly when weeds compete too long with corn, according to a recent article in The Bulletin.

Controlling weeds early with a properly timed application of a post-emergence herbicide is key.  The problem is not all post-emergence herbicides are as effective as they used to be; glyphosate-resistant weeds are a growing problem.

“Sixty percent of farmers reported they have seen a decrease in the effectiveness of the glyphosate system – compared to 45 percent just 24 months ago,” said Damon Palmer, Dow AgroSciences U.S. commercial leader for the Enlist™ Weed Control System.

Farmers need alternative weed control systems, and that’s one of the reasons that I’m so excited when new tools to fight weed resistance come along like the Enlist weed control system (2,4-D) and the new Genuity Roundup Ready 2 Xtend (Dicamba).

It’s frustrating to see a new tool like Enlist Corn receive unsavory media attention, leading to public outcry based on fear rather than fact.  Just a few days ago CBS News aired a story entitled, “Controversy flares over ‘Agent Orange corn’.”

CBS compares the new Enlist Weed Control System with Agent Orange, which was widely used during the Vietnam War. Some people even use “2, 4-D” and “Agent Orange” interchangeably, but that’s not correct.

The chemical 2,4-D has been used safely in this country since it was initially registered back in the 1947 and was reregistered in 2005.   While Agent Orange did contain 2,4-D like Enlist does, the two products are very different.  Enlist does not contain the 2,4,5-T component of the herbicide or its contaminant, dioxin, as Agent Orange did.

Let’s focus on the facts and wage the war against weeds, not against the companies that make the weed control products or the farmers who plant food for a growing world population.

Volunteer corn is not a crop… it’s a weed that grows from grain left in fields after a harvest.  Farmers should treat volunteer corn like a weed and manage it early in the season.

Three main reasons why volunteer corn should be managed early:

1. Volunteer corn competes with newly planted crops for nutrients.
2. Volunteer corn attracts corn rootworms.
3. If left untreated, volunteer corn could potentially reduce the benefit of crop rotation.

Like any weed, volunteer corn competes with the growing crop for nutrients.  Volunteer corn is a yield robber!  It’s even more competitive with soybeans.  Soybean yields can be reduced by populations of volunteer corn at 8,000 to 16,000 plants/acre.  Corn yield also can be reduced by populations of volunteer corn of at least 8,000 plants/acre, according to research trials by the University of Minnesota.

Another reason volunteer corn is a concern is because it creates a “safe harbor” for corn rootworms.  Corn rootworm typically hasn’t been a problem when fields are rotated annually between corn and soybeans because soybeans starve out rootworms that hatch in spring.  However, volunteer corn allows rootworm larvae to complete their feeding cycles.

In addition to being a food source for rootworm larvae, volunteer corn that is not controlled by tasseling attracts corn rootworm beetles for egg laying.  The beetles lay their eggs in the soil around the base of the volunteer corn.  The eggs will remain dormant until they hatch the next spring.

Bottom line:  Higher numbers of volunteer corn can build higher corn rootworm populations for the next growing season.  Higher rootworm numbers are especially problematic when those fields are planted to corn the following year in a corn-soybean rotation or in continuous corn.

It’s time to turn our attention to early season weed management.  It’s important for farmers to walk fields right after emergence and at least once weekly thereafter, so they can keep ahead of the insect and weed pressure.

Be on the lookout for large-seeded weeds like giant ragweed, sunflower and cocklebur.  These weeds are always tough to control and should never be allowed to get established.  There were several weed species that took advantage of the early warm temperatures and got an early start: lambsquarters, waterhemp and other pigweeds.  Check your fields as soon as possible to see how successful your weed control measures have been.

Additional measures like increased rates of post-emergent herbicides, spot-spraying or even hand weeding may be necessary to keep these from becoming an ongoing problem.  I’ve also noticed a lot of foxtail and other grasses as well as volunteer corn starting to show up in area fields.  Now’s the time to be scouting your fields for these potential problems so that you stay ahead of them in your efforts to keep your fields clean.

Existing weed vegetation should be controlled with tillage, herbicides, or a combination of tactics, so the crop can become well established under weed-free conditions. Early-season weeds rob yields you cannot see at harvest. Crops have a better chance of reaching optimal yield when they’re not competing with weeds for sunlight, water and nutrients.

Walking fields and noting where there is weed pressure will help you determine an action plan.  Take field notes and indicate where you’re seeing the pressure.  Depending on your findings, you may need to change modes of action.  Weed resistance is a growing concern.  Literally.  That’s why Latham Hi‑Tech Seeds offers farmers choices.

Be proactive and manage your weeds before they become a problem.  Also manage herbicide resistance before it becomes a major problem.  Know what herbicides you are using, what they control as well as what they do not control, what replant restrictions exist and whether there is significant potential for crop injury.