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4/11/2011 - 4/17/2011

Expiration of Biotech Crop Patents – Issues For Growers

By Roger McEowen, Center for Agricultural Law and Taxation

In the near future, the last of the Roundup Ready soybean patents will expire. That expiration will be followed by the expiration of other patents on biotech crops and expiring approvals in overseas markets like the European Union and China.

Those expirations could lead to the planting of so-called “generic” versions of Roundup Ready seeds that lack approval in overseas markets, complicating the export process and potentially disrupting billions in trade. Whether the expirations will lead to lower seed prices and more choices for farmers is an open question and greater use of the historic practice of saving some seed and replanting it in the next crop season remains to be seen. But, as patents expire and regulatory approvals for overseas markets become uncertain, a significant question exists as to whether farmers will continue to have access to these markets.

Certainly, as patents begin to expire on various biotech crops, those crops will remain for a period of time in the commercial grain supply chain. That means that steps will likely be necessary to ensure that the crops will still meet requirements imposed by certain buyers such as the European Union and China. Without those steps, U.S. farmers could face problems in maintaining access to those markets. Another potential problem could arise if the holder of the expired patent develops and markets a new product that could potentially compete with the product for which the patent has expired (the so-called generic product).

The patent expiration of the first generation of RR soybean trait in 2014 will be the first time that a major biotech trait will become potentially subject to competition with generic traits. That could result in lower prices and more choices for farmers. That will most likely be the case if Monsanto sticks to its pledges to maintain and extend current licensing agreements and regulatory approval for overseas markets.

Certainly, Monsanto has legal options that it can utilize to extend its existing monopoly and prevent competition among generic seed products. It appears at the present time that Monsanto does not plan to utilize those options to the extent of diminishing competition in the seed market. But, this entire matter is one that is developing.

A complete brief on this topic is posted on the Center for Agricultural Law and Taxation website as an April 8, 2011 –  Expiration of Biotech Crop Patents – Issues for Growers. This article looks at the laws governing seed sales and the current landscape.



Roger McEowen is the Iowa State University Center for Agricultural Law and Taxation director and an agricultural law professor. He can be reached at or 515-294-4076.

Stewardship, Yields, Money and Resistance

By Mike Owen, Department of Agronomy and Tamsyn Jones, Corn and Soybean Initiative

A consistent theme the last few years has been the need to provide stewardship for glyphosate- and glufosinate-resistant crops in order to preserve the value these traits bring to agriculture. Consider that there are a number of ways to provide stewardship, and one way that does not. Unfortunately, the one way that does not provide stewardship – recurrent use of the herbicide to which the crop is resistant – continues to prevail. I anticipate that we will have a breakout year for glyphosate-resistant weeds, particularly waterhemp, in 2011. Thus, the many ways to provide stewardship must be considered – or crops and growers alike will suffer the consequences.

Soil-applied residuals for weed stewardship

One option is the use of a soil-applied residual herbicide(s) that is/are cleverly selected to control the most problematic weeds (i.e. waterhemp). However, appropriate application timing is an important part of effective stewardship.

The worst way to use a residual herbicide is to apply it post-emergence to the crop and weeds alone or in combination with a post product such as glyphosate. While this type of application is convenient and simple, it results in loss of most of the stewardship benefits (e.g. yield protection and better time management) accrued by residual herbicides. Applying soil-applied residual herbicides post-emergence allows weeds to compete with crop yield potential and does not provide any time management benefits relative to the other suggested herbicide application timings.  

The best and least risky application timing is early pre-plant (EPP) – which means now is the time to make applications. An EPP application results in the herbicide being in place to control weeds as they begin to germinate and precludes the loss of yield potential attributable to early-season weed interference. Importantly, the EPP timing does not interfere with planting, thus providing the greatest time management benefit.

The next best timing is pre-emergence (PRE) application timing. The PRE application timing also potentially provides similar weed control benefits as the EPP – but there is greater risk of insufficient rainfall to provide the appropriate environment for effective weed control. Also lost is the time management benefit provided by the EPP application timing.

Considerable data generated from a five-year field-scale on-farm project (Benchmark Study) conducted in Iowa clearly and consistently demonstrates the benefits of soil-applied residual herbicides when the application timing is correct. The benefits include:

  • greater yields compared to post treatments, regardless of whether the latter included a residual herbicide
  • more profitability; and
  • other stewardship benefits resulting from this tactic, such as mitigation of herbicide-resistant weed populations.

There is one other bit of troubling news to consider: Waterhemp populations have evolved resistance to HPPD herbicides (e.g. Callisto, Impact, and Laudis).  While not yet widely distributed, unless appropriate stewardship of this class of chemistry is provided, it is inevitable that HPPD resistance will become prevalent across Iowa.  Act now to steward HPPD herbicides.



Micheal Owen is a professor of agronomy and weed science extension specialist with responsibilities in weed management and herbicide use. Owen can be reached by email at or by phone at (515) 294-5936. Tamsyn Jones is a communications specialist with the Corn and Soybean Initiative. Jones can be reached at (515)294-7192 or email at

Iowa Learning Farms’ Webinar Offers Tips on Nitrogen and Water Quality

By John Lundvall, Department of Agronomy

The Iowa Learning Farms’ (ILF) April webinar, to be held Wednesday, April 20 at noon, will feature Matt Helmers, who will talk about in-field nitrogen management and drainage design and its impact downstream. The webinar is part of a series, hosted by ILF, held on the third Wednesday of each month. The webinars will be held over the noon hour through Adobe Connect. All that is needed to participate is a computer with Internet access.

Helmers is an Iowa State University Extension water resources engineer, researching the impacts of agricultural management on water flow and quality. He is passionate about water quality and the affects of agricultural practices on Iowa’s water bodies.

In this webinar, Helmers will discuss water quality impacts of various in-field management practices including rate and timing of nitrogen application, use of drainage water management and shallow drainage and various land covers. He will be able to answer questions from webinar “attendees” via the Adobe Connect chat box.

To connect to the webinars, go to: Those new to Adobe Connect should visit the ILF website to download a PDF file with detailed connection instructions. The ILF website homepage contains links for archived webinars from previous months: Please contact ILF with other topic ideas for future webinar sessions.

Corn Nitrogen Rate Calculator Update

by John Sawyer, Department of Agronomy


What is the Corn Nitrogen Rate Calculator?

The Corn Nitrogen Rate Calculator Web tool is a resource that aids nitrogen (N) rate decisions for corn production and is helpful in determining the effect of fertilizer and corn price on application rates. The method for calculating suggested N rates is based on a regional (Corn Belt) approach to N rate guidelines. Details on the approach are provided in the regional publication Concepts and Rationale for Regional Nitrogen Rate Guidelines for Corn. This approach and the Corn Nitrogen Rate Calculator are now being used by seven states across the Corn Belt: Iowa, Illinois, Indiana, Michigan, Minnesota, Ohio and Wisconsin.


Nitrogen (N) Response Trials Added

The Iowa N response database in the calculator was recently updated, with response trials added from 2010 research. There are now 200 trials for corn following soybean and 101 trials for corn following corn. Being able to easily update the database with recent data is one of the many advantages to this dynamic database approach for corn N rate guidelines. Having new response trial data allows rapid updating with changing hybrid genetics, rotations and climatic conditions.

With the updated database, calculated N rates have increased slightly from previous years. The table below gives the N rate at the maximum return to N (MRTN) and the profitable N rate range from the updated calculator for several N:corn grain price ratios. You can work with any price of N and corn you wish when running the calculator. Output information includes the N rate at the MRTN, the profitable N rate range, the net return to N application, the percent of maximum yield, and the selected N fertilizer product rate and cost.


Resources for N Rate Decisions

The Corn Nitrogen Rate Calculator Web tool is located at

The regional publication Regional Nitrogen Rate Guidelines for Corn (PM 2015) can be ordered through any ISU Extension county office, from the ISU Extension Online Store at, or by calling 515-294-5247. An electronic copy of the publication is available at

The ISU Agronomy Extension Soil Fertility website is located at:


John Sawyer is professor with research and extension responsibilities in soil fertility and nutrient management.

Wait to Plant Corn with Forecast of Impending Cold Spell

By Roger Elmore, Department of Agronomy

Four-inch soil temperatures passed the 50 degrees Fahrenheit mark in the past few days, air temperatures broke 80 degrees Fahrenheit over the weekend, soil moisture conditions in many areas are good, and the sun is shining. Because of this, I am receiving many questions on whether we should start planting corn. Rain is expected by mid-week across much of the state and air temperatures may drop below freezing by this next weekend. This calls for a caution flag.
While our current planting date data identifies the best time frames to start planting begin this week for the three Iowa regions and end at varying times, there is more to consider. 

Corn seed absorbs 30 to 35 percent of its weight in water during germination. Soil temperatures have little effect on this process. However, the time required for radicle emergence is tied to temperature; it increases linearly if soil temperatures are between 46 and 90 F. Little, if any, mesocotyl or coleoptile growth occurs in soils cooler than 60 F. A constant soil temperature of 86 F optimizes seed germination and seedling emergence.  

Once the seed begins to germinate, a significant change in soil temperature can cause problems. Research shows that a swing of soil temperatures of 27 F (soil high temperature-soil low temperature) will affect mesocotyl growth. It is possible that corn planted this week will experience this range of temperatures. Seed placed into the ground, yet not emerged, can be injured from a cold period. The drop in soil temperature can cause erratic and uneven stands as it did across the state in 2006, resulting in crop development that varied up to two developmental stages between plants in the same row. Seedlings can also have stunted and distorted leaves or may not emerge from the soil.

Given the current conditions and the forecast for cool-wet weather, the best place for seed this week is probably in the bag.

For more information, please see “Early season cold stress” by Elmore and Lori Abendroth.


Roger Elmore is a professor of agronomy with research and extension responsibilities in corn production. Elmore can be contacted by email at or (515) 294-6655.

This article was published originally on 4/18/2011 The information contained within the article may or may not be up to date depending on when you are accessing the information.

Links to this material are strongly encouraged. This article may be republished without further permission if it is published as written and includes credit to the author, Integrated Crop Management News and Iowa State University Extension. Prior permission from the author is required if this article is republished in any other manner.