Maturity-group ranges below are typical, not rules. Use them as a starting point alongside your state's variety trials.
Northern Plains
Watch for
- Iron deficiency chlorosis on high-pH soils
- White mold in cool, wet years
- Short season and early frost risk
- SCN spreading north
Practices that pay
- Choose IDC-tolerant varieties for calcareous fields
- Higher seeding rates on IDC-prone ground
- Plant promptly once soils warm — the season is short
- Narrow rows help fast canopy
Western Corn Belt
Watch for
- SCN (widespread) and SDS
- IDC in parts of western Iowa and Minnesota
- White mold in the north
- Herbicide-resistant waterhemp
Practices that pay
- Early planting into fit soils for yield
- Rotate SCN resistance sources and sample soil
- Layer residual herbicides and match program to trait
- Irrigated Nebraska ground can support fuller-season MGs
Eastern Corn Belt
Watch for
- SCN, SDS and Phytophthora on heavy, poorly drained soils
- Frogeye leaf spot increasing in the south
- Wet springs delaying planting
Practices that pay
- Pick strong Rps genes plus field tolerance for wet soils
- Seed treatments on early-planted and no-till fields
- Use FLS-resistant varieties where frogeye is common
- Fuller-season MGs in central/southern areas when planted early
Great Plains
Watch for
- Drought and heat at pod fill
- Charcoal rot under hot, dry stress
- Dectes stem borer in some areas
Practices that pay
- Match MG to moisture — earlier MGs can escape late-summer drought
- Irrigation scheduling at R3–R6
- Conserve residue to hold soil moisture
- Double-crop after wheat where rainfall allows
Mid-South & Delta
Watch for
- Frogeye leaf spot, Cercospora, aerial web blight
- Stink bugs and other insects at pod fill
- Charcoal rot and heat stress
- Root-knot and reniform nematodes
Practices that pay
- Early Soybean Production System: MG 4–5 planted in April
- Furrow or pivot irrigation timing
- Fungicide decisions around R3 with multiple modes of action
- Scout for stink bugs from R3 onward
Southeast
Watch for
- Root-knot nematode on sandy soils
- Soybean rust in some years near the Gulf
- Kudzu bug and stink bugs
Practices that pay
- Double-crop after wheat is common — plant promptly
- Choose nematode-resistant varieties for sandy fields
- Later MGs for full-season plantings in the Deep South
Mid-Atlantic & Northeast
Watch for
- Slugs in no-till, cover-cropped fields
- White mold in cooler northern areas
- Frogeye and SCN further south
Practices that pay
- Full-season and double-crop systems side by side
- Monitor slugs at emergence in heavy residue
- Match MG closely to latitude — the range is wide
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