Dr. Robert L. Nielsen
Professor of Agronomy
Extension Corn Specialist
915 W. State Street
Department of Agronomy
Purdue University
West Lafayette, Indiana 47907-2054
Office: 3-450
Lilly Hall
Telephone: 765.494.4802
FAX: 765.496.2926
Email: rnielsen at purdue.edu
My Responsibilities at Purdue University
Extension education in corn management systems.
- Transgenic crop issues
- Corn growth and development
- Understanding the effects of stress on corn
- Stand establishment issues in corn
- Corn replant decision-making
- Yield-limiting factors in corn production
- Crop problem troubleshooting
- Site-specific crop management technologies
- Working with yield monitor data
- Technology transfer & distance education via the World Wide Web
- Managing the downside risks of continuous corn
- Guidelines for on-farm research
- Managing nitrogen fertilizer for corn
- Profitable corn management practices
My Web sites
Extension Publications
Publications marked with the
symbol require the Adobe
Reader plugin.
Publications that are not available online may be ordered through Purdue's
Media Distribution Center.
- Corn and Soybean Field Guide: 2012 Edition (ID-179)
- 2012
Purdue Crop Guide (ID-166)

- The Making of Effective Extension Presentations (PPP-81)
- The online version is a very large PDF file (22MB).
- Arrested Ear Development in Corn (BP-85-W)

- Estimating Yield and Dollar Returns From
Corn Replanting (AY-264-W)
- Delayed Planting & Hybrid Maturity
Decisions (AY-312-W)
- Corn Growth & Development: What
Goes On From Planting to Harvest? (AGRY-97-07)

- USDA Grading
Standards and Moisture Conversion Table for Corn (AY-225)

- The Indiana 4-H Corn Project -- Corn: The Plant, Problems, and Products (4-H 672)
- The Indiana 4-H Corn Project -- Hybrid Corn: Selecting, Growing, Harvesting, Using (4-H 763)
- The Indiana 4-H Corn Project -- Corn Growth: Nutrients, Tillage, Hybrids, and Production (4-H 674)
- Stand Establishment Variability in
Corn (AGRY-91-01)

- Planting Speed Effects on Stand Establishment
and Grain Yield of Corn (AGRY-94-02)

- Perspectives on Narrow Row Spacings For
Corn (AGRY-96-17)

Since the mid'1990's, I focused on using the Web for publishing online newsletter articles, rather than numbered Extension publications, about many aspects of corn production. Most of them are archived in my Corny News Network Archives.
Research interests in corn management systems.
- Corn Yield Response to Seeding Rates (2001 - )
- Corn Yield Response to Nitrogen Fertilizer Rates (2006 - )
- Optical Reflectance Sensors & Their Potential for Fine-tuning N Rate Recommendations in Corn (2006 - )
- Effects of Uneven Plant Spacing on Corn Grain Yield (2004 - 2006)
- Post-Emergence Spray Applications & Arrested Ear Development (2008 - 2011)
- Response of Corn to Early Applications of Foliar Fungicides (2012 - )
A Fun Extension Project:

Presentations, Papers, etc.
I have
begun to convert my online Powerpoint® presentations to Adobe® Flash®
versions that should be less memory-intensive to download and play. They require
Adobe's Flash Player which is a standard add-on to most of today's Web browsers.
If you need to download and install the Flash Player, go to the Adobe download
site at http://get.adobe.com/flashplayer.
- Advanced farming systems and new technologies for the maize industry

- A written summary of a presentation developed for the 2012 New Zealand Maize Conference, Hamilton, NZ, Feb 2012. Sponsored by the Foundation for Arable Research, Lincoln, NZ.
- © 2012, Purdue Univ.
- Serving the Information Needs of Tomorrow's Farmers
- A recording of a presentation made by yours truly at the 2011 American Society of Agronomy Annual Meeting, San Antonio, TX. This presentation was part of a symposium organized by the ASA titled "Advancing Agronomy Through Public-Private Collaboration".
- Abstract: Federal, state, and county funding support for the overall Cooperative Extension effort continues to erode and certainly begs the question about the sustainability of our capacity to provide independent, research-based agronomic information to farmers in the U.S. Results from numerous grower surveys lead some to further question whether agronomic Extension will be necessary in the future given the ever-increasing reliance by growers upon the agronomic advice and recommendations provided by agri-businesses and private consultants. Beyond the question of fiscal sustainability for Extension, there is the equally if not more important philosophical question whether farmers' agronomic needs are best served by a healthy combination of public and private efforts in agronomic research and education.
- Thoughts
on Row Spacing and Plant Population

- This presentation shares my thoughts and opinions about row spacing and plant population decisions for corn. The presentation was developed for the Illinois Ag Masters Conference, Dec 2010. A PDF summary of the presentation slides is also available on-line at http://www.kingcorn.org/talks/2011_RowSpacing&Pop.pdf.
- © 2011, Purdue Univ.
- A
Practical Guide to On-Farm Research

- This presentation discusses the practical ins and outs of conducting your own on-farm research. A written summary of this presentation is also available on-line at http://www.kingcorn.org/news/timeless/OnFarmResearch.pdf.
- © 2011, Purdue Univ.
- Thoughts About Yield Monitor Calibration

- This presentation shares my thoughts and opinions about the calibration of yield monitors. A brief summary about yield monitor calibration is also available on-line at http://www.kingcorn.org/news/timeless/YldMonCalibr.html.
- © 2009, Purdue Univ.
- Thoughts About Hybrid Selection

- This presentation shares my thoughts and opinions about the challenges and rewards of choosing hybrids wisely.
- © 2009, Purdue Univ.
- Optical
Reflectance Sensors & N Rate Decisons for Corn

- This presentation highlights our research with optical reflectance sensors and their potential for helping fine-tune nitrogen rate decisions for corn.
- © 2008-2009, Purdue Univ.
- Corn Planter Tuneups: Why Bother?
- Online Powerpoint presentation (Req.
IE v5.0 or newer)
Powerpoint® 2002 version (10.8 MB)
Adobe PDF version (Presentation view) (2.2 MB)
Adobe PDF version (Handout view) (1.6 MB) - A presentation on the importance of uniform plant-to-plant spacing and emergence in corn, plus guidelines on improving planter performance..
- © 2002-2004, Purdue University.
- Stand Establishment Issues & Concerns for No-Till Corn
- Powerpoint® 2000
version (19.1 MB)
Adobe PDF version (Presentation view) (3.5 MB)
Adobe PDF version (Handout view) (1.7 MB) - This presentation discusses the issues and challenges of achieving successfull stand establishment in no-till corn. Suggested agronomic decisions for improving stand establishment are described.
- © 2003, Purdue University.
- Protecting Your Non-GMO Grain From Contamination
- Powerpoint® 2000
version (4.0 MB)
Adobe PDF version (Presentation view) (2.1 MB)
Adobe PDF version (Handout view) (1.8 MB) - Certain transgenic corn traits available to U.S. corn growers are not yet fully approved in the global marketplace, especially by the European Union. Consequently, certain U.S. grain buyers restrict their purchases to that from only approved hybrids and reject grain from non-approved hybrids or grain from fields of approved hybrids that is "contaminated" with transgenic grain. This so-called "contamination" can occur from mechanical mixing (commingling) of grain from different hybrids during planting, harvesting, or post-harvest operations. Pollen drift from transgenic hybrids can also cause "contamination" of neighboring fields due to cross-pollination. Consequently, growers who desire to maintain the non-transgenic purity of the grain in their production fields need to understand corn pollen biology, the dynamics of pollen drift, and possible methodologies for minimizing the risk of significant pollen "contamination" from adjacent fields of non-approved corn hybrids.
- © 2003, Purdue University.
- Key Crop Management Issues for Optimizing Grain Yield & Quality
- Adobe PDF version (Presentation
view) (1.8 MB)
Adobe PDF version (Handout view) (1.6 MB) - Adobe Acrobat formatted summaries of a presentation made at the 5th Australian Maize Conference, held 18-20 Feb, 2003, in Toowoomba, QLD.
- © 2002-03, Purdue University.
- Maize: New Uses for an Old Crop
- Adobe PDF version
(Presentation view) (1.3 MB)
Adobe PDF version (Handout view) (1.2 MB) - Adobe Acrobat formatted summaries of a presentation made at the FAR New Zealand Maize Conference, held 12-13 Feb, 2003, in Hamilton, New Zealand.
- © 2002-03, Purdue University.
- Maize GE Benefits & Bugbears in the U.S.
- Adobe PDF version
(Presentation view) (1.7 MB)
Adobe PDF version (Handout view) (1.4 MB) - Adobe Acrobat formatted summaries of a presentation made at the FAR New Zealand Maize Conference, held 12-13 Feb, 2003, in Hamilton, New Zealand.
- © 2002-03, Purdue University.
- Developments in Agronomy & Maize Management
- Adobe PDF version
(Presentation view) (1.5 MB)
Adobe PDF version (Handout view) (0.9 MB) - Adobe Acrobat formatted summaries of a presentation made at the FAR New Zealand Maize Conference, held 12-13 Feb, 2003, in Hamilton, New Zealand.
- © 2002-03, Purdue University.
- Profitable Corn Management Strategies & Production Practices
- Powerpoint® 2000 version (18.4
MB)
Adobe PDF version (Presentation view) (3.6 MB)
Adobe PDF version (Handout view) (2.3 MB) - Timeless ideas and suggestions for improving agronomic efficiencies, and thus profitability, of corn production in Indiana.
- © 2002-03, Purdue University.
- Corn Growth & Development Related to Herbicide Use
- Adobe PDF version (Presentation
view) (1.5 MB)
Adobe PDF version (Handout view) (460 KB) - Many post-emergence herbicide labels restrict the size or age of corn that can be treated. This Adobe Acrobat formatted version summarizes a presentation made at the 2003 Southwest Indiana Corn and Soybean Day held in Vanderburgh County, Indiana, on 10 January 2003 that offers insight into the uncertainties of determining corn growth stages relative to herbicide usage.
- © 2003, Purdue University.
- Life's Little Corn Problems: Tips on Crop Diagnostics
- Adobe PDF version (Handout view) (4.5 MB)
- This presentation shares my experiences in the art of crop diagnostics, including what questions to ask, how to look at a field, how to resist the know-it-alls, how to locate that missing puzzle piece, how to sneak away from the crowd, how to stick your foot in your mouth, and how to hem and haw with the best of them. I also share some experiences with photography, including digital imagery, from the perspective of capturing these precious moments in crop diagnostics. This Adobe Acrobat document summarizes a presentation given at the 2002 Nebraska Independent Crop Consultant Association Spring Workshop and revised for the 2002 Mid-Atlantic Crop Management School in Maryland.
- © 2002-03, Purdue University.
- Stalk Rots and Lodging in Corn
- Adobe PDF version (Presentation view) (1.4 MB)
- Stalk rots and accompanying root & stalk lodging in corn can be devastating in their effects on yield and harvest losses. This Adobe Acrobat document summarizes a presentation given at a grower conference in southern Indiana in November 2001.
- © 2001, Purdue University.
- Sparse Versus Dense Spatial Data
- Online Powerpoint™ presentation
- An online version of a talk presented at the 2000 Purdue Top Farmer Crop Workshop that emphasizes the importance of dense data sets for interpolating spatial variability for yield influencing factors.
- © 2000, Purdue University.
- Understanding Factors That Limit Yield in Corn
- Online Powerpoint™ presentation
- An on-line slide presentation of issues relevant to the potential for improving yields with Precision Farming technology.
- © 1998, Purdue University.
- Establecimiento Variable en el Maíz y Su Efecto en la Producción de Grano
- (Spanish - español)
- Online Powerpoint™ presentation
- Adapted from a presentation given at the VI National Corn Congress, Pergamino ARGENTINA, 12 - 14 Nov 1997. The Congreso Nacional de Maíz was organized by the Asociación de Ingenieros Agrónomos de la Zona Norte de la Pcia. de Bs. As. (AIANBA).
- © 1997, Purdue University.
My Background
- Raised on farm in southeast Nebraska near Springfield.
- Graduated from Springfield-Platteview High School of South Sarpy County School District #46.
- Obtained B.S. in Agronomy from the University of Nebraska
- Obtained M.S. and Ph.D. in Plant Breeding from the University of Minnesota









