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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.
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.
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.
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.
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.
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.
By Roger Elmore and Lori Abendroth, Department of Agronomy
Increased seeding rates have ignited corn yield increases over the years. If seeding rates are the spark, hybrid genetics fuel the increase. It takes both high seeding rates and high-yielding hybrids that can tolerate increased plant-to-plant competition to maximize yields. If hybrids were not bred to tolerate increased seeding rates, we would have fields of flat corn at harvest. Older hybrids simply cannot tolerate today’s seeding rates without severe lodging and/or barrenness.
By Rich Pope, Department of Entomology
Today the first weekly report of base 50°F degree-day accumulations is posted for the 2008 Iowa crop season. Statewide, the first four days of May have accumulated degree days at the long-term average, but that follows a cooler-than-normal April.
By John Sawyer and Roger Elmore, Department of Agronomy
Our best information from planting date experiments show that corn yields are reduced as we plant into the second half of May. However, looking at planting progress and corn yields over the years, we see that although yields are increasing and in general we are planting earlier every year, above average yields can occur with delayed planting and below average yields can occur with early planting (see Sidebar article ‘Corn Planting Progress‘ from Wisconsin).
By Greg Tylka and Chris Marett, Department of Plant Pathology
N-Hibit™ is a seed-treatment that contains harpin protein, a compound that can stimulate plant defense responses. N-Hibit™ is now being sold in the United States for management of the soybean cyst nematode (SCN). Iowa State University evaluated the effects of N-Hibit™ seed treatment on soybean yield and SCN population densities in experiments at nine locations throughout Iowa in 2007.
