Blog

I've noticed potato leafhoppers in soybean this week (nymphs and adults), plus several notable observations are coming my way. It's time to get out a sweep net to  alfalfa and soybean so you can make timely treatment decisions. Depending on where you are in the state, you might be close to the second cutting or a few weeks away. It is important to distinguish leafhopper injury, sometimes called hopperburn, from other issues in the field. 

Recent floods throughout Northwest Iowa have caused significant damage and loss to communities, homes, roads, livestock producers, crops and more. Unfortunately, this situation will continue long after the rain as high river levels continue to surge south.

Heavy rain across northern Iowa resulted in major flooding in areas. For those dealing with flooding, additional resources can be found here ranging from farm and home to cleaning up after flooding. Read on for more specifics about what Iowa State University Extension and Outreach field agronomists saw over the last week.

Heavy rainfall can have economic and environmental consequences if flooded fields are left barren. Long-term damage to soil needs to be considered when planning for next season's crop.

Biological, chemical and physical soil health

The torrential rains that northern Iowa experienced last week may have favored several diseases of corn including crazy top, Physoderma brown spot and node rot, Goss’s wilt and bacterial stalk rot. While there are no in-season management practices for these diseases, correct diagnosis can help with disease management options in future years including choosing hybrids with resistance.

Crazy top

European corn borer, known as “the billion-dollar bug,” was a pest of economic concern in the United States prior to the commercialization of Bt corn hybrids in 1996. With the widespread adoption of Bt traits, European corn borer populations have been effectively managed and areawide suppression provided benefits to farmers that did not use Bt.

Summer annuals are valuable to forage production systems due to their heat and drought tolerance. These high-yielding crops are typically ready for grazing within 40-45 days under optimal conditions, making them ideal for double cropping systems. They provide excellent options for silage, baleage, hay, and grazing.

Areas in Iowa remained on the drier side last week while other areas received some heavier rain and even some isolated large hail in areas. Herbicide injury, Asian copperleaf, tar spot, nitrogen management, and weeds surviving herbicide applications were some of the hot topics or issues Iowa State University Extension and Outreach field agronomists saw over the last week. Read on for more specifics.

As we enter summer, most of our cool-season dominant pastures have headed out, or the grasses have started producing seed heads. The common question of whether to mow the seed heads arises. The decision to mow or not is site-specific. Mowing can remove seed heads, stimulate even grazing, and provide some weed control, but these benefits do not always outweigh the labor and fuel costs.

The weather the last week was again drier than previous weeks, but also plenty windy some days. The drier conditions provided opportunities for lots of field activities including replating, spraying, making hay, and sidedressing. Prevent or delayed planting, herbicide injury, true armyworms, sandblasted crops, and nitrogen loss concerns were some of the hot topics or issues Iowa State University Extension and Outreach field agronomists saw over the last week. Read on for more specifics.

You won’t want to miss any of the upcoming field days hosted at the outlying Iowa State University Research Farms this summer. These field days will feature the latest information on crop production and management practices. Below is a list of the upcoming field days that will take place as well as what topics will be featured at each field day. All field days are free and open to the public.

There is no 2024 Weed Science Field Day at the Curtiss Farm in Ames, IA planned for 2024. However, weed management and herbicide research experiments of interest are available for viewing. Interested parties should contact Damian Franzenburg (dfranzen@mail.iastate.edu or 515-294-5358) to arrange for a tour.  Industry representatives and farmers are welcomed.

The trapping season for black cutworm (BCW) has come to an end. We appreciate our cooperators for tirelessly checking traps the last two months and reporting their captures so we can provide the most accurate scouting information for these pests. To recap, we had 25 volunteers participate from 24 counties in Iowa. A total of 29 BCW traps were placed and monitored during April and May.

The last week brought some drier weather across the state for farmers to get back in the fields to plant as well as for other field activities to be completed including spraying, putting up first cutting hay, and sidedressing. Delayed planting, replant decisions, yellow corn, white grubs, true armyworms, weed pressure, and nitrogen loss concerns were some of the hot topics or issues Iowa State University Extension and Outreach field agronomists saw over the last week.

Over the last week, we've seen a lot of active weather across the state. In addition to tornadoes, wind, and heavy rains, areas across the state also got hit with hail. 

Moth flights into Iowa were drastically reduced during Week 8 (May 19 to May 25), partly because of fewer moths but also likely due to the fact that recent storms took out several traps across the state. Our cooperators recorded only 51 black cutworm (BCW) moths and, for the first time since Week 1, no significant flights were recorded.

This is part one of a three-part series on nitrogen management this spring. Read part two, “Navigating Nitrogen Management in Wet Spring Conditions – Estimating Nitrogen Losses,” and part three, “Navigating Nitrogen Management in Wet Spring Conditions – Does the corn need more nitrogen?”.

This is part three of a three-part series on nitrogen management this spring. Read part one “Navigating Nitrogen Management in Wet Spring Conditions – Nitrogen Loss Mechanisms” and part two “Navigating Nitrogen Management in Wet Spring Conditions – Estimating Nitrogen Losses.”

Do I need to apply additional nitrogen?

This is part two of a three-part series on nitrogen management this spring. Read part one, “Navigating Nitrogen Management in Wet Spring Conditions – Nitrogen Loss Mechanisms,” and part three, “Navigating Nitrogen Management in Wet Spring Conditions – Does the corn need more nitrogen?”.

While the title is written with some jest, the sentiment is one I’ve been thinking about a lot this spring. With few highly effective postemergence herbicide options for waterhemp control, farmers must prioritize residual herbicides as a first line of defense. While there are numerous residual herbicides available, most soybean residual programs are based on the PPO inhibitors (HG 14).