Integrated Crop Management News

Links to these articles are strongly encouraged. Articles may be republished without further permission if published as written and if credit is given to the author, Integrated Crop Management News, and Iowa State University Extension and Outreach. If articles are used in any other manner, permission from the author is required.

La Nina Diminishes

May 23, 2008

By Elwynn Taylor, Department of Agronomy

The La Nina of the past several months as determined by the 90-day average Southern Oscillation Index (SOI) has ended. The SOI is a measure of the atmospheric pressure deviation from normal and directly influences meteorological conditions in numerous distant locations. The SOI diminished to 0.8 standard deviations on May 19, 2008. 

Where Do I Get Weather Information?

May 23, 2008
Screenshot of the page

By Elwynn Taylor, Department of Agronomy

There are several sources of weather information available to help farmers make informed crop production decisions.

To see the forecast for your ZIP code go to Click the general location of interest within the U.S. map. Now click your “exact” location (if you miss it a bit you get a chance to put in your ZIP code.)

Finally! A Good Work Week

May 20, 2008
Image of base 50 degree F degree days in regions of Iowa from May 1 to May 18, 2008

The last week found Iowa farmers able to get to the field, and crop planting progress advanced notably. Although the week followed the seasonal temperature trend, being a bit cooler than average, the rain held off for the most part.


Emerged corn can now be found across Iowa, and soybean planting is well underway.


Update on Fungicides for Use on Soybean

May 20, 2008

By Daren Mueller, Department of Plant Pathology

There have been some changes in the availability of fungicides for soybean. Here is a quick summary.

Alto® (cyproconazole, Syngenta Crop Protection) has been fully registered for use on soybean by EPA. The product will be available for use on soybean in Iowa when the new label is approved by the state. Until then, this product will only be available through its Section 18 label for soybean rust.

Black Cutworm Thresholds: What has Changed with the Price of Corn and New Control Methods?

May 16, 2008

By Jon Tollefson and Marlin Rice, Department of Entomology

Black cutworm traps across Iowa have been capturing migrating moths for several weeks. Pheromone traps are valuable tools in integrated pest management, but they have limitations. The traps only tell you that the insects are in your area; they do not report in which fields the insects have laid their eggs.

Black Cutworm Scouting Advisory—2008

May 16, 2008
Map of the projected dates of first cutting: black cutworm

By Marlin E. Rice, Rich Pope, and Jon Tollefson, Department of Entomology

A significant flight of black cutworm adults (moths) arrived in Iowa the weekend of April 18, based on pheromone trap capture data across the state.

Minimize Soybean Yield Loss from Late Planting

May 13, 2008
Model of soybean planting date response in Iowa based on soybean yield potential

By Palle Pedersen, Department of Agronomy

Soybean responds significantly to early planting. Despite cold soil temperatures and slow plant growth during the seedling phase, there is a yield benefit from early planting, which seems to be influenced by field yield potential.

A Bit Cool, a Bit Wet, but Planting Progresses

May 13, 2008
Image of base 50 degree F degree days in regions of Iowa from May 1 to May 11, 2008

By Rich Pope, Department of Entomology


The second week of May continued the 2008 pattern of cool and wet spring weather across Iowa. in spite of a band of locally heavy rain the evening of May 7 that brought over 6 inches of rain to Alden and neighboring areas, corn planting progressed slowly but steadily.