Ryegrass Control in Conventional Field Corn (Prostko)

Lucy Ray from Morgan County recently asked me about ryegrass control in conventional field corn.  Here are my thoughts:

1.  I contacted several local GA corn seed reps to see what conventional hybrids with tolerance to ALS-inhibiting herbicides would be recommended in Georgia.  The short list is as follows: Dekalb 68-37 or 66-02 or 111-30; Integra 6588; Dyna-Gro 57CC51; Pioneer 1608 or 17677; and AgriGold A645-16.
2. Ryegrass is extremely difficult to control in conventional corn.  Expectations should be fair/marginal at best. NO miracles here!
3. Three postemergence herbicides are available for use in conventional corn that have some activity on ryegrass (again not great but all we got).  These include Accent Q (nicosulfuron), Revulin Q (nicosulfuron + mesotrione), and Steadfast Q (nicosulfuron + rimsulfuron).  These herbicides cannot be used if Counter is applied in-furrow for soil insect/nematode management.  
4. My suggested weed control program for this scenario would be as follows (reduced tillage/strip tillage): 

1. Prior to planting, if ryegrass and other winter weeds are emerged, split shot of Gramoxone 3SL (paraquat) @ 32 oz/A (~10 days apart) + COC @ 1% v/v (1 gal/100 gal). In the second shot, add Dual II Magnum 7.64EC (S-metolachlor) @ 16 oz/A for residual control of annual grasses and broadleaf weeds.  This second shot of Gramoxone + Dual II can be applied before or after planting (but before corn emergence).  The goal here is to start off as clean as possible.
2. At V3-V5 stage of corn, apply either Accent Q 54.5WDG @ 0.9 oz/A or Steadfast Q 37.7WDG @ 1.5 oz/A or Revulin Q 51.2DF @ 3.5 oz/A + Atrazine 4L @ 64 oz/A + NIS @ 0.25% v/v (1 qt/100 gals).  Remember these are not great (for ryegrass/crabgrass) but all we have for POST grass control in conventional corn.  

    5)  FYI, ryegrass is one of many weeds that does not like deep tillage (i.e. turning plow).

Positive Pesticide Points (Prostko)

It's not too often that the general public hears any positive information about the safe use of pesticides in agriculture. In 1991, the U.S. Department of Agriculture (USDA) Agricultural Marketing Service (AMS) was charged with designing and implementing the Pesticide Data Program (PDP) to collect data on pesticide residues in food. Congress mandated the program in the 1996 Food Quality Protection Act (FQPA). The results of the 2024 PDP Annual Summary were recently published.  Here are the highlights:

1) 9,872 food samples were tested

2) Fresh and processed foods tested were as follows: almonds, apples, avocados, blackberries (fresh and frozen), cherry tomatoes, cucumbers, head lettuce, leaf lettuce, onions, oranges, pineapples (fresh and frozen), potatoes, canned pumpkin, sweet corn (fresh and frozen), tomatillos, and salmon. 

3) Domestic samples accounted for 60.1% of all samples, while 38.9% were imports, 0.9% were of unknown origin, and less than 0.1% were of mixed national origin.

4) Over 99% of the samples tested had residues below the tolerances established by the EPA with 42.3% having NO detectable residue.  

5) As a reminder, the U.S. EPA determines the maximum residue levels (MRL’s) or tolerance of pesticides in food products based upon a standard 100-fold margin of safety to protect all people and the environment.  In addition to this base margin of safety, the FQPA of 1996 imposed an additional 10-fold safety factor (1000X) to protect infants and children, unless sufficient evidence is presented to reduce (Reeves et al., 2019. Adv. Nutr. 10:80-88).

6) A copy of the complete report can be found at the following web-address:

https://www.ams.usda.gov/sites/default/files/media/PDPAnnualSummary.pdf

7) Spread this good news when you have the opportunity to talk to someone about pesticides/agriculture!