Carrington REC Agronomy Q&A
Wednesday, May 13, 2026
Shareable link: https://ndsu.zoom.us/rec/play/7bMRXirNjDEjvzbsC3hxoHA7jAlqdXFzB6l4ZBNPNv9UEVlJJMUJdqYDFLN-5aSOmXxoFn6U5wcw0amV.hChd0CvRk8Ir_vaC
Resources shared during the call:
Registration is OPEN for this year’s Crop Management Field School, Wednesday, June 24, 2026! Read the details at www.ndsu.ag/CMFS26 or register direct at www.tinyurl.com/payCREC .
Summary of the Meeting Transcript
1. Weather Outlook & Field Conditions
Jeff opens with an extended weather forecast for North Dakota. Key points include:
- Warm temperatures through Saturday, then a sharp cool-down with highs 48–60°F from May 17–23.
- Frost risk around May 17–19. Depending upon the lowest temperature and the duration of the lowest temperature will depend upon whether frost or freeze damage could occur to emerged corn and soybean. It will not get cold enough to damage emerged small cereal crops, field pea, or likely flax.
- Rain forecasts keep shifting, but most areas may receive 0.3–0.42 inches early next week.
- More rain chances around May 21, 26–27, and early June.
- Rain is “much needed… for pre-emergence herbicides, but also for those that have planted seeds into dry soil”.
- High winds are causing soil movement and damaging emerged crops.
2. Herbicide Options for Cover Crops
Jeff reviews pages 105–106 of the Weed Control Guide:
- Brassicas are the most sensitive to many herbicides.
- Lentils and flax show sensitivity to several wheat herbicides.
- Soybean pre-emergence programs relying on sulfentrazone essentially eliminate the option of brassica cover crops.
- Brassica cover crops can only be planted after a small grain cereal crop to allow for enough growth. Brassica cover crops seeded with soybean leaf drop or earlier or in corn between the V5 to V8 stage may allow enough time for successful brassica species cover crop establishment. Planting cover crops in a standing corn or soybean crop is tricky due to the herbicides applied in those crops and the injury they can or will cause to the cover crop species planted.
3. Discussion: Planting Barley or Rye With Soybeans to Reduce Wind Damage
One participant asked about planting barley or rye with soybeans to protect seedlings from wind.
Jeff’s response:
- Carrington REC has tested rye and barley as protective cover.
- Rye works well but requires careful termination timing to avoid drying out soils.
- Barley planted in the spring has been used successfully with dry beans and could help with soybeans.
- Oats should be planted in IDC-prone areas because they take up the most excess nitrogen, reducing iron deficiency chlorosis risk.
Quote: “Rye is a great cover crop… The more biomass and root growth, the more coverage of the soil, therefore the greater the weed control”.
4. Preemergence Herbicides in Dry Conditions
Major concerns discussed:
- Applying preemergence herbicides to dry soil causes them to bind to soil particles rather than move into the weed germination zone.
- Wind erosion can physically remove herbicide-treated soil, reducing efficacy and potentially harming downwind crops.
- Most modern herbicides can remain on the soil surface 10–20 days without degrading, but activation requires moisture.
- Incorporation (PPI) of herbicides is an option but requires proper equipment (field cultivator is the best, not vertical tillage). Vertical tillage tools do not uniformly distribute PPI herbicides to obtain uniform and effective weed control.
Quote: “If we apply herbicides to these dry surfaces, it's gonna be attached to the soil particles right now… instead of being mixed with the water”.
5. Seed Treatments in Cold, Dry Soils
One participant asked whether seed treatments remain effective in cold and dry soils.
Key points:
- Cold, dry soils do not degrade seed treatments; they remain on the seed coat until moisture arrives.
- Cold, wet soils are more problematic because chemicals can leach away before uptake and plants grow slowly allowing for a longer time period for infection.
- Typical seed treatment efficacy window is 14–21 days, possibly up to a month depending on product.
- Wheat may still benefit from seed treatments if:
- Seed is scabby
- Loose smut is present
- Wheat is grown too frequently in rotation
- Root rots (especially Rhizoctonia) are a concern
6. Insect Activity in Cold Weather
Anitha explains:
- Insects are cold‑blooded; cold temperatures slow or stop their activity.
- Seed treatments remain inactive until the seed imbibes water.
- Cold, slow-growing crops remain vulnerable longer, but insects also feed less.
Quote: “When it is cold, they don't even try to eat. They just lay inactive”.
7. Preemergence Herbicides vs. Emerging Weeds
I was mentioned from out west weeds (pigweed, wild oats, quackgrass) are emerging ahead of crops.
Jeff’s guidance:
- Even a tenth of an inch of rain can help activate preemergence (PRE) herbicides.
- If weeds emerge from the soil before herbicide activation, PRE’s will not control them.
- For kochia and waterhemp, preemergence herbicides are essential due to widespread resistance.
- Zidua offers the best residual kochia and waterhemp control, but requires significant rainfall and is costly.
8. Alfalfa Planting Timing
- Historically, mid-May is the cutoff.
- This year, planting may be feasible until Memorial Day, depending on rainfall.
- Late planting increases risk due to poor establishment moisture.
9. Soil Salinity Issues
A major discussion topic:
- High salinity is more visible than usual due to:
- The wet 2025 growing season and into the fall
- Deep frost
- Lack of significant spring rains
- Capillary action with water is pulling salts from 5–6 feet deep to the surface.
- Tillage worsens salinity by drying soil and increasing upward salt movement.
- Many farmers still till and plant through saline areas, losing $183–$676 per acre in these non-productive areas of the field.
Quote: “We’re increasing the salt concentration farther away from the main spots… I’ve never seen salts higher in elevation outside these low spots than this spring”.
A new NDSU publication on salt‑tolerant species is forthcoming.
10. Governor’s Program for Saline Acres
- Provides funding to seed salt‑tolerant plant species.
- Current rules limit haying/grazing, which reduces effectiveness.
- Advocates hope to expand the program in the next legislative session.
11. Closing
Jeff encourages feedback and notes:
- Sessions are recorded.
- An AI summary (like this one) will be posted online.
- Follow-up information will be shared with participants.
