Integrated Crop Management News

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Factors Needed to Maximize Corn Yield Potential in 2008

August 30, 2008
Table of predicted corn yields for different regions of Iowa

By Roger Elmore and Lori Abendroth, Department of Agronomy

The start of the 2008 growing season was extremely difficult for planting and crop establishment, however, environmental conditions since have been fairly good. What type of yields should we expect from this turbulent season? What will it take to obtain high yields from this point in the growing season forward? And, the other side of that question – what don’t we want to see happen?

Producers and Applicators Legally Responsible to Heed Preharvest Intervals for Treated Soybean

August 30, 2008
Table of insecticides labed for use in Iowa soybeans and days to harvest after application

By Marlin E. Rice, Department of Entomology

Based on reports from my Extension agronomist colleagues, hundreds of thousands of soybean acres were sprayed with insecticides during July and August for control of soybean aphids and bean leaf beetles. All insecticides listed in Table 1 have at least a 21-day preharvest interval, and several have moderate intervals of 30 days or very long preharvest intervals of 60 days. The preharvest interval is the minimum number of days a farmer must wait before harvesting a treated crop.

Credit Needs and Cash Rents Impacted by Higher Input Costs

August 25, 2008

By William Edwards, Department of Economics
Corn and soybean farmers have been enjoying record high prices and sizable profits for their past two crops.  But higher input prices will eat into those margins in 2009.

Soybean Top Dieback Shows Up in Iowa Again

August 25, 2008
Close view of top dieback

By XB Yang, Plant Pathology Department, John Saywer, Agronomy Department

Extension field agronomists report the occurrence of soybean top dieback in northeastern Iowa soybean fields this week. Soybean top dieback symptoms have shown up occasionally since it was first reported by Jim Fawcett and Jerry Long in Cedar County a few years ago. Last year it was also found in eastern and central Iowa.

Pre-harvest Restrictions for Fungicides

August 24, 2008
Table of corn/soybean foliar fungicides and their preharvest intervals

By Daren Mueller, Department of Plant Pathology

With the buzz of airplanes still being heard out in the countryside and September within sight, this is just a quick reminder to growers about the pre-harvest intervals (PHI) for fungicides applied to corn and soybean. Last month in Kansas, some wheat was embargoed when fungicide levels were questioned until tests could be completed to determine residue levels.

Changes in Retail Fertilizer Market Impact Producers

August 22, 2008

By Roger Ginder, Department of Economics
Major change in retail fertilizer markets over the past three years include price volatility and price increases. But, in addition to the unprecedented price volatility, basic changes in the trade practices at the manufacturing, wholesaling, and retail levels in the fertilizer value chain are affecting producers.

A Final Soybean Aphid Alert

August 20, 2008

By Jon Tollefson and Marlin Rice, Department of Entomology

For supposedly being a soybean aphid “off year”, the aphids have been doing surprisingly well during August. Typically the aphid numbers are declining at this time of year because the soybeans are approaching maturity and the temperatures are quite warm. However, this year is slightly different from recent years and you should not let down your guard.

Fill ‘er Up!

August 19, 2008
Graph of 2008 degree day accumulations from May 1

By Rich Pope, Department of Plant Pathology

In a season that started with weather tumult fouling up the planting season in many areas, we have done pretty well in getting the corn and soybean to reproductive stages. Degree days remain behind long-term averages as of August 17.

Goss’s Wilt Prevalent in Western Iowa

August 12, 2008
Image of dark green to black freckles characteristic of Goss's wilt

By Alison Robertson, Department of Plant Pathology and Laura Jesse, Plant and Insect Diagnostic Clinic

This past week several corn samples infected with Goss’s wilt were submitted to the Iowa State University Plant and Insect Diagnostic Clinic. Tamra Jackson at University of Nebraska, Lincoln has also reported an increase in the prevalence of Goss’s wilt in Nebraska this growing season (see Crop Watch, August 8, 2008). 

Plan for 2009 Crop Year by Managing Flooded Soils

August 11, 2008

By Mahdi Al-Kaisi, and Stephen Barnhart, Department of Agronomy
Approximately 1.2 million acres of Iowa farm land affected by flooding early this year have not been planted to any crop. There are potential economic and soil environmental consequences of leaving these soils unattended. The long-term damage to soil and water quality in areas of significant flooding need to be considered when planning for next season’s crop.