Airing of Grievances: Stress vs Deficiency - RDA 501

Recorded live at KNID AgriFest in Enid from the Oklahoma Wheat Commission booth, Episode 501 launches Season 5 with a fast-paced crop check and a whole lot of agronomy banter.
Dave Deken sits down with Brian Arnall and Josh Lofton to talk January wheat realities: dry conditions, odd winter insect pressure, and early reports of wheat diseases showing up sooner than anyone wants.
They also hit canola concerns—like that purple color—and what to inspect right now (new leaves and crown health) as everyone looks ahead to green-up.

Next, it’s go-time thinking for topdress: why timing, weather, and surface conditions matter—especially when warm days, wind, and dew can increase nitrogen losses.
Then the conversation turns into a practical deep dive on plant physiology and decision-making: primordia (the “cells in waiting”), how early-season stress can differ from true deficiency, and why chasing genetic potential without respecting environmental limits can hurt ROI.
If you like your agronomy with real-world nuance (and a little friendly arguing), this one’s for you!

Top 10 takeaways

1. January crop scouting can be misleading—weather swings can make fields look great or “go backwards” fast.
2. Warm winter + dry stretch = unusual pest pressure, including armyworms in wheat.
3. Early disease reports (tan spot, rust, powdery mildew) mean don’t assume “it’s too early.”
4. For canola right now, focus on new leaves and crown—that’s your “are we okay today?” check.
5. Green-up moisture is the hinge point for both wheat tillering and canola recovery.
6. Topdress timing is a system problem (acres, co-op schedules) and a weather-loss problem (dew + warm + wind).
7. If conditions are right to lose N (dry soil + dew/humidity + wind), waiting can be the most profitable move.
8. A lot of management is about what’s happening inside the plant—primordia/cell division—before you ever see it.
9. Stress can be useful; deficiency is where you start giving away yield potential—context (stage/goal) matters.
10. The “right” program depends on your risk profile: protecting max yield vs protecting ROI on inputs.

Detailed timestamped rundown

00:00–01:15 — Welcome to Episode 501 + Season 5 vibes; shoutout to AgriFest and the Wheat Commission cinnamon-roll traffic.
01:16–01:55 — Introductions: Dave Deken with Dr. Brian Arnall and Dr. Josh Lofton; “we were arguing in our office earlier…”
01:46–02:10 — Recorded Jan 9, 2026 at the Oklahoma Wheat Commission booth during AgriFest in Enid.
02:10–03:05 — Cinnamon roll banter + meeting listeners at the booth.
03:07–04:20 — Crop update headline: it’s January, it hasn’t rained, it feels like June; armyworms in wheat; disease confirmations in SW OK.
05:01–06:20 — Canola check: purple color mystery; focus on new leaves + crown health “right now.”
06:35–08:10 — “Magic windows” talk: green-up moisture is critical for canola and wheat tillering.
09:03–10:30 — Rooting + grazing: planting timing affects anchoring; some fields pull easier under cattle.
10:45–12:55 — Topdress season starts early for many; best efficiency late Jan–March; avoid warm/windy/dewy days that can increase N loss (they cite “blow off 15–25%”).
13:00–16:55 — What if winter doesn’t get cold? Daylength and growth timing; discussion on how wide the N window really is.
17:00–22:10 — OSU NPK blog topic: managing “primordia” (cells-in-prep), not just what you see aboveground.
22:10–25:20 — Corn example: by V6 you’ve set rows/potential kernels; stress/deficiency can reduce grain number.
28:50–41:10 — Main debate: stress vs deficiency, “leaf deficient but not the plant,” and Liebig’s Law barrel analogy.
44:20–48:10 — Genetic vs environmental potential, realized yield; precision vs accuracy; risk aversion (yield loss vs input cost).
49:40–50:17 — Wrap + resources at reddirtagronomy.com.

RedDirtAgronomy.com