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Following the derecho event on August 10, millions of acres in Iowa face challenging conditions. In many cases the corn may be unharvestable. These unharvestable fields require some level of fall management to ensure the future crop can achieve even emergence and normal early plant growth.

The combination of drought, derecho and recent hot weather in Iowa increases the need to keep grain quality in check. As harvest nears, consider the following:

Corn fields destroyed by the August 10, 2020 derecho will have different crop residue than normal after grain harvest. Things that will be different include early plant death (at varying reproductive growth stages), ears at various stages of grain fill, and whole plants instead of “loose” stalks/leaves/husks after grain harvest (unless tilled). The amount of vegetative material, except for some husk material, basically reaches a maximum around R1- silking.

Dear regulators,

Rainfall still eludes most of the state of Iowa, and drought has continued to envelope the state, with the driest areas expanding from the west central part of the state. Crops continue to go downhill in the drought and the derecho areas, especially with the warmer temperatures of this week.

Chopping silage during rapid drying conditions always bring up the question of “How much water do I add?” The short answer: It is practically impossible to add enough to get to your desired moisture level. 

Fall Management Options for Corn Fields That Are Unharvestable

Millions of corn acres have been damaged by the derecho on August 10. Unfortunately for some of these acres, harvest will not take place. Decisions regarding fall management options will need to be made in the coming weeks.

To help with those decisions, let’s focus on some key considerations:

The unprecedented August 10 derecho storm event has caused significant damage to Iowa corn fields. If it’s decided to proceed with harvesting the field for grain, several operational changes may increase performance and productivity of the combine.

The range of soybean gall midge has expanded in 2020. There are three new counties in Iowa (Osceola, Dickinson, and Calhoun) for a total of 29. So far, 108 total counties are confirmed in Iowa, Minnesota, Missouri, Nebraska, and South Dakota. Likely more counties have soybean gall midge but haven’t scouted yet.

Observations from Iowa agronomists, farmers, and myself this summer:

While much of the damage from this month’s derecho is due to strong hurricane-force winds, isolated pockets of hail affected crops also, particularly in parts of Carroll, Greene, Hamilton, Hardin, Boone, and Story counties.  When addressing any crop damage, contact your crop insurance provider as soon as damage is identified to determine coverage and avoid loss of coverage.

Wind and storm damaged soybean have been reported across Iowa, creating yet another stress for farmers this growing season. Certain fungicide products are marketed as being capable of reducing stress in crops, so should they be sprayed on soybean this late in the season?  

Fungicide response to damaged crops

Caterpillars have been extremely active this year, especially in soybean. We suspect that late-season infestations of caterpillars in corn are no exception. These infestations are serious because these caterpillars feed on the ear and/or tunnel into stalks. Their feeding can also lead to secondary infestations of other, less common insects, and severely infested fields can be at risk for ear molds and mycotoxins. August is an excellent time to scout for ear-feeders.

When steel grain bins sustain wind damage, careful inspection is needed to evaluate repair or replacement options. Inspection assistance and advice from a consulting engineer or bin manufacturer representative is the best option.

Monday’s derecho event took a toll on crops across Iowa. Satellite imagery shows millions of acres of Iowa crops impacted by the high wind events. As growers dig out from the destruction left after the storm, decisions regarding how to manage the impacted crop will be front and center.

While some rainfall has come to the droughty areas of the state, drought intensified to D3 (extreme) drought in parts of central and west central Iowa. Unfortunately, a large swath of the state is now facing devastating infrastructure and crop damage after the August 10 Midwest Derecho. Our thoughts are with all Iowans as they work to assess and recover from damage.

Drought conditions persist in western Iowa and have expanded further into central and north central Iowa this week.

In the interview, “A Farmer’s Journey with Miscanthus: Part 1,” we learned about Steve Schomberg and his involvement with growing miscanthus for the University of Iowa power plant. Steve has also been working with Koch Angus Farms, a cattle production farm near Letts, Iowa for the last four years. During this time, he got to know Scott Hintermiester, a herdsman for Koch Angus, who manages the day to day operations for the last two years.

ISU Extension and Outreach field agronomists, Meaghan Anderson and Angie Rieck-Hinz, recently partnered with their extension colleagues at the University of Minnesota to organize and deliver the second webinar series, Essential Row Crop Management.  This series featured four topics discussing mid-season crop management.  The topics included Tar Spot identification and in-season management, Soybean Aphid IPM, Corn Rootworm Management and Soybean Gall Midge update. 

Over the last two weeks I have received a few calls related to identifying a “new form of waterhemp” in Southwest Iowa. In reality, we do not have a new form of waterhemp, but a condition referred to as ‘fasciation’ (Figure 1). While this can occur in many plant species, plants like cacti and members of the sunflower family (Asteraceae) are more likely to have fasciation of stem cells. However, we’ve noticed it quite commonly on waterhemp this year, so what’s going on? 

While the drought concerns and drought impacts on row crops and forage crops seems to be the big issue especially in western Iowa, other common issues or questions reported by ISU Extension field agronomists this past week included corn rootworm activity, earworm feeding, Japanese beetles causing defoliation in soybeans and silk clipping in corn, low levels of soybean aphids, potato leafhopper damage, gray leaf spot pressure increasing (especially eastern Iowa), low levels of frogeye leaf spo