Encyclopedia Article

To optimize yield, producers must try to use an optimum seeding rate, planting date, row spacing, etc. However, these factors are continually changing. For example, why are seeding rates increasing and planting dates becoming earlier? Find information here that addresses these questions and other topics that are important before and during planting.

Extension Newsletter Articles

Planting Date

Corn and Dry Soils at Planting-Looking ahead to 2012 Part I
Part II: Hybrid maturity changes?
Part III: Plant population changes?
Corn hybrids adjust to late planting dates (2011)
Wait to plant corn with forecast of impending cold spell (2011)
Updated planting date recommendations for Iowa (2010)
Planting date trends (2010)
Corn planting: Consider soil temperature and date
Hybrids adjust to delayed planting dates
Planting date considerations for corn following corn


Replant checklist (2010)
Impact of early season frost (before V4)

Plant Population

Update on corn plant populations and seed costs
Seeding rates in relation to maximum yield and seed costs
Corn seeding rates and variable-rate seeding
Evaluate seeding rate relative to seed cost
Plant population considerations for corn following corn

Row Spacing

What row spacing is best?

Planter Speed and Uniformity

First step to achieving uniform plants (2011)
How does planter speed affect plant spacing?
Tillage not found to affect plant space uniformity
How to measure plant to plant spacing in corn
Accurate tools for measuring plant uniformity


How much corn can we plant on a good day in Iowa? (2011)
Remember to check planter settings (2010)
Do corn kernel size and shape matter?

Extension Publications

Corn field guide (see pages 10-13)
Corn Planting Guide

Photograph of corn seedlings

Related Websites

USDA Prospective Plantings
USDA Crop Acreage Reports
USDA Weekly Weather & Crop Bulletin
USDA Crop Progress & Condition
Soil Temperatures
Growing Degree Days
Soil Growing Degree Days
Soil Moisture

Iowa State University Agronomy Extension Corn Production