Spring cleaning fields - tips for terminating cover crops

By Blake Jackson

Spring is here and it's time to prepare your fields for planting! This article offers key tips for terminating cover crops and winter cereals harvested for forage, ensuring a clean slate for your next crop.

Chopping Not the Answer for Rye:

Chopping rye or triticale before they flower (anthesis) won't effectively kill them. Research shows significant regrowth after chopping at various stages.

Post-Harvest Herbicide for Rye:

Spraying rye with herbicides before harvest is illegal. The best approach is to use a post-harvest application.

Glyphosate vs. Paraquat for Rye:

Glyphosate (at 1.13 lbs acid equivalent per acre) is generally more effective than paraquat for killing rye after harvest. Timing is flexible; you don't need to wait for regrowth if enough green leaf tissue remains for herbicide uptake.

Tailor Your Termination Plan:

Consider the weeds present in your cover crop. A healthy cover crop suppresses many weeds, but some may persist. Adjust your herbicide choice or timing to target these specific weeds.

Tank-Mix Options for Cover Crops:

Glyphosate or paraquat alone might not be enough for all cover crop types.

For legumes and brassicas, adding synthetic auxins like dicamba or 2,4-D LVE to the mix improves control.

Always check herbicide labels for preplant application restrictions and compatibility with your planned crop (corn or soybean).

Herbicide Restrictions and Best Practices:

• Sharpen: Apply 0-14 days before planting corn (1-3 oz/acre) or soybeans (1 oz/acre). Use methylated seed oil and ammonium sulfate.
• 2,4-D LVE & Dicamba: Apply at least 7 days before planting corn (0.5-1 lbs acid equivalent per acre).
• Clethodim: Apply SelectMax more than 6 days before planting corn (6 fl oz) or pre-emergence in soybeans (up to 8 fl oz). Refer to labels for other clethodim products.
• Metribuzin: Tank-mix with paraquat before corn or soybeans (0.2 lbs a.i. per acre). Check label for rate adjustments based on soil type.
• Atrazine: Tank-mix with paraquat before corn only (1 lb a.i. per acre).
• Rimsulfuron: Apply Resolve 25 DF or Basis Blend 30WDG (1 oz/acre) in corn only.

Photo Credit: gettyimages-mvburling