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As corn and soybean are taken out of fields, some fields may reveal an unexpected mat of Asian copperleaf lurking below the canopy. As of this summer, we’ve identified Asian copperleaf (Acalypha australis) in crop fields in eight counties: Calhoun, Humboldt, Boone, Wright, Franklin, Hardin, Grundy, and Black Hawk. Early identification of this species is key to adopting effective management tactics to reduce its spread to other fields.
Soybean aphid is still the most important insect pest of soybean in Iowa, despite low populations throughout the state in recent years. This summer, we have seen high populations throughout Iowa, with hundreds of aphids per plant, honeydew, and sooty mold development on leaves. We have also heard various reports about performance issues with pyrethroid applications. This has prompted many questions about when to spray soybean aphids and which insecticides to use.
Key Points:
Corn earworm is a pest that causes direct injury to corn ears. Corn earworms do not survive winters above the 40th parallel but some migrate north to the Corn Belt every year. Economic injury in field corn is uncommon due to the high adoption rate of Bt traits in Iowa (e.g. Cry1Ab, Cry1F, Cry1A.105+Cry2Ab2, Vip3A). However, non-Bt sweet corn and popcorn is at risk every growing season, and the financial impact in these specialty crops is especially important.
Weed communities in three cropping systems suitable for the Midwestern USA were studied from 2017 through 2020 to examine how crop diversification and the intensity of herbicide use affected weed stand density and aboveground mass. A baseline 2-year cropping system with corn and soybean grown in alternate years was diversified with cool-season crops, namely oat and red clover in a 3-year system, and with oat and alfalfa in a 4-year system. Herbicides were not used in the cool-season crops.
Farm fields that have been covered with flood waters may need structural (physical) repair before returning to full production. Flood debris, sand, silt, erosion, and loss of soil structure may all result as residual effects of flooding.
Before You Begin
Grasshopper activity in field crops has picked up recently, and these jumpy insects and their defoliation have caught the attention of crop scouts and agronomists across the state. Grasshoppers tend to thrive under dry conditions, and although most areas have received adequate moisture in 2024, consecutive drought years have likely led to higher than usual populations. This article discusses identification, scouting and management of grasshoppers in corn and soybeans.
Identification and Life Cycle
Those looking for any bit of good news among all the rain-soaked suffering we have endured this growing season have asked if the overabundance of moisture has drowned SCN. Unfortunately, the answer is no.
Nematodes are worms (animals) that require oxygen. And they absorb oxygen through their body wall or cuticle, which is made almost exclusively of proteins. Waterlogged soils may have greatly reduced levels of oxygen, but many plant-parasitic nematodes, including the soybean cyst nematode (SCN), can survive long periods of time with little oxygen.
AMES, Iowa – Extreme rains in northwest Iowa have caused instances of stored grain being covered with floodwater. According to current Food and Drug Administration policy, grain inundated by uncontrolled river or stream water is considered adulterated and must be destroyed. The current situation is one of river water flooding rather than of rain-driven pooled water in low ground, for which there are salvage options. River-based floodwaters can bring in many hazards and rapid spoilage.
Flooding affects both the stored grain and the storage structures.
The spring has certainly looked a little different than previous years. What does it mean for disease development? With some of our more destructive diseases – sudden death syndrome (SDS) and white mold – the rains have certainly increased the chances of disease developing.
