Integrated Crop Management News

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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.


Consider Effects on Seedbed Before Tilling Wet Soil

May 13, 2008

By Mark Hanna, Department of Agricultural and BioSystems Engineering, and Mahdi Al-Kaisi, Department of Agronomy

The current weather conditions of frequent rain caused saturated conditions in most Iowa soils. Tilling soil for drying the soil surface or weed control at this time may have significant negative impacts on creating proper seedbed conditions and increase soil compaction.

Beware of a Dangerous Invasive Weed -- Updated

May 12, 2008
Image of cow parsnip

By Mike Owen, Department of Agronomy

Upon further investigation about the location of “local” infestations of the highly invasive giant hogweed, it was determined that the Wisconsin location is in Iron County which is located at the northern boundary between Wisconsin and the Upper Peninsula of Michigan (see colored area on the map). Gogebic County, Michigan also has or had infestations of giant hogweed. The U.S. Forest Service is working diligently to eradicate these populations.

Delayed PRE Herbicide Applications in Corn

May 12, 2008
Table of herbicide options available for corn

By Mike Owen, Department of Agronomy

Given the way the season has developed, the best intentions to apply an Early Preplant (EPP) herbicide application prior to corn planting has gone out the window and it appears that applying a preemergence (PRE) application immediately after planting is also becoming a slim chance. Thus, many who intend to use a soil-applied residual herbicide treatment in corn may be forced to make the application of an early postemergence (EPOST) to the weeds and possibly the corn.