Cover Crop Interseeder: Potential for Injury from Corn Herbicides
This list includes herbicides we have evaluated for use with interseeding annual ryegrass and medium red clover in corn. The herbicides rated green have a low potential for injury, yellow, medium or moderate potential for injury, and pink have a high potential to injury cover crops. These ratings pertain to work performed in the mid-Atlantic region and is not necessarily applicable to other regions of the country. This is an ongoing project.
The table below provides some guidelines for herbicide use in the mid-Atlantic region with interseeded cover crops.
Potential for Cover Crop Injury (% Fall Biomass Reduction)
<15% = LOW (L) 15-30% = MODERATE (M) >30% = HIGH (H)
| Herbicide Treatments | Product Rate | Label Rate | App Timing | Annual Ryegrass | Red Clover | Grass-Legume Mix |
| SUs (2) | ||||||
| Resolve 25 DF | 0.5 oz | ½X | PRE | L | L | L |
| Resolve 25 DF | 1 oz | 1X | PRE | L | L | L |
| Triazines (5) | ||||||
| Atrazine (4L) | 1 pt | ½X | PRE | L | M | M |
| Atrazine (4L) | 2 pt | 1X | PRE | M | M | M |
| Atrazine (4L) | 3 pt | 1 ½X | PRE | H | H | H |
| Metribuzin 75 WG | 4 oz | 1X | PRE | H | L | M |
| Chloroacetamides (15) | ||||||
| Dual II Mag 7.64 EC | 1.67 pt | 1X | PRE | H | M | H |
| Zidua 85 WG | 2.5 oz | 1X | PRE | H | M | H |
| Harness 7 EC | 1 pt | ½X | PRE | M | L | M |
| Harness 7 EC | 2 pt | 1X | PRE | M | L | M |
| Outlook 6 EC | ½ pt | ½X | PRE | L | L | L |
| Outlook 6 EC | 1 pt | 1X | PRE | M | L | M |
| Dinitroanilines (3) | ||||||
| Prowl H2O 3.8 CS | 1.5 | ½X | PRE | L | L | L |
| Prowl H2O 3.8 CS | 3 pt | 1X | PRE | H | M | H |
| PPOs (14) | ||||||
| Sharpen 2.85 SC | 1.5 fl oz | ½X | PRE | L | L | L |
| Sharpen 2.85 SC | 3 fl oz | 1X | PRE | M | M | M |
| HPPDs (27) | ||||||
| Balance Flex 2 SC | 5.3 fl oz | 1X | PRE | M | M | M |
| Callisto 4 SC | 5.4 fl oz | 1X | PRE | L | H | H |
| Impact 2.8 SC | 0.75 fl oz | 1X | POST | M | H | H |
| Mixtures | ||||||
| Keystone LA NXT | 2 pt | ½X | PRE | L | L | L |
| Prowl + Atrazine | 1.5 pt+1 pt | ½X | PRE | M | M | M |
| Harness + Resolve | 1 pt+0.5 oz | ½X | PRE | L | L | L |
| Verdict 5.57 EC | 8 oz | ½X | PRE | L | L | L |
| Lumax EZ 3.67 SE | 1.35 qt | ½X | PRE | H | H | H |
| Acuron 3.44SC | 1.25 qt | ½X | PRE | H | H | H |
Potential for interseeded cover crop injury from residual corn herbicides (Pennsylvania Guidelines).
