It was a warm, dry, and windy week across the state last week. Planting is winding down across the state, and the early planted corn fields are reaching the V4-V5 stages and soybeans earlier planted soybeans are around V1. Weeds coming through PRE herbicides, soil crusting, replant decisions, sand-blasting/leaf-tattering, and herbicide/seed treatment injury were some of the common issues or concerns heard by the ISU Extension field agronomists. Read on for more specifics about what is happening across the state.
Leah Ten Napel (Region 1):
Cherokee, Ida, Lyon, Monona, O'Brien, Osceola, Plymouth, Sioux, Woodbury counties
“Corn and soybeans are emerging all across northwest Iowa. Some early planted corn fields I have seen are in the V4 to V5 stages. Early planted soybeans are V1 to V2. Soils were very fit for planting so emergence seemed to go smoothly in most fields. Recent and upcoming rainfall is welcomed. Pastures have been a little slower to grow without moisture. Insect reports have been low. Weeds are emerging and possibly cutting through PRE’s a little early. Strong winds may delay spraying and could cause issues with weed escapes down the road.”
Gentry Sorenson (Region 2):
Buena Vista, Clay, Dickinson, Emmet, Hancock, Kossuth, Palo Alto, Pocahontas, Winnebago counties
“The corn growth stage is V2 to V3, with most corn planting completed. Northern Iowa has had high winds, and some corn was sandblasted or received leaf damage from the wind over the past week. Soybeans range from recently planted to VC to V1. Soybean planting is completed in most fields. Emergence looks good for corn and soybeans across region 2. I have not had any calls on emergence issues to date, and fields that I visited looked good due to optimum conditions at planting. It’s a great time to do stand assessments in your field if you have a challenging area of a field to understand the stand count and reason for the low stand. Phone calls have been on wind/sandblasted corn and pasture weed questions.”
Angie Rieck-Hinz (Region 3):
Cerro Gordo, Franklin, Hamilton, Hardin, Humboldt, Webster, Worth, Wright counties
“Last week was warm and dry and the later part of the week was warm, dry and so very windy. The dry conditions allowed farmers to again make significant progress in planting, so much so, it is difficult to find non-planted fields. Corn ranges from just planted to V4 and soybeans from just planted to V1. The majority of field calls and phone calls last week related to replanting decisions based on several factors: crusting soils, planter issues, a few erosion issues moving seed out of furrow from previous rains, drowned out spots and herbicide issues. I anticipate we will again see some replants after the 5/19-5/20 rains that caused a lot of ponding. I have also had multiple phone calls about crop condition concerns based on the windy conditions causing “sandblasting” and leaf tattering in fields. I did receive one phone call regarding slug feeding in a no-till soybean field, so continue to scout! Finally, I have been seeing a lot of ILEVO® “halo effect” in soybean fields (photo). The Crop Protection Network recently published an article summarizing the interaction (or lack of) of Using ILEVO with Preemergence Herbicides. This can occur when soybeans are slow to emerge in cool soils. "
Terry Basol (Region 4):
Benton, Black Hawk, Bremer, Butler, Chickasaw, Floyd, Grundy, Howard, Mitchell counties
“Dry conditions pursued throughout this past week, allowing farmers the opportunity to finish corn and soybean planting. Due to some isolated crusting issues, there have been some replanting operations within the area, primarily for corn, but some soybean acres as well. For the early planted acres, corn is emerging and ranges from VE to V2, although I was in a corn field yesterday that was planted in April that was at V4. Soybeans range from just planted to the VC stage for the earliest planted acres in the area. Continue to scout for germinating weeds and begin to evaluate species and where they occur throughout the field, potential pressure, weed height, and timing of the first post emerge application. Because we’ve had dry weather conditions without precipitation since the PRE herbicide applications, many products weren’t activated. We now have weeds that have germinated and will need to be controlled with a POST application. According to the USDA-NASS Crop Progress Report, as of May 18, 97% and 83% of the acres have been planted to corn in NC and NE Iowa, respectively. For soybeans, 88% and 78% of the acres have been planted in NC and NE Iowa, respectively. Warm temperatures have continued to accelerate the development of alfalfa this past week. First cutting of alfalfa has begun in NC/NE Iowa with stands looking very good for quality. Insect activity (such as alfalfa weevil) has remained non-existent to very low in most of the alfalfa stands here in the area. It was a dry week last week with no measurable amounts of precipitation received here at the Northeast Iowa Research Farm.”
Josh Michel (Region 5):
Allamakee, Buchanan, Clayton, Delaware, Dubuque, Fayette, Jones, Linn, Winneshiek counties
“A second week of dry weather allowed planting to continue across most of the region. An estimated 90% of the corn has been planted, while soybeans are at 80% planted. Some of the early planted corn has reached V2, while the earliest planted soybeans are at VC to V1. Approximately 80% of the oats have emerged, with the very earliest about to start heading out. Some producers even took advantage of the dry weather and put up the first crop of alfalfa. Pastures continue to look good and anticipated rainfall this week should keep them going strong. The majority of field calls this past week centered around corn and soybean stand assessments and replant decisions, weed identification and management, and adjusting herbicide programs.”
Meaghan Anderson (Region 7):
Boone, Dallas, Jasper, Madison, Marshall, Polk, Story, Tama, Warren counties
“Last week was a very dry week in central Iowa, which allowed nearly all planting fieldwork to finish. The wind at the end of the week halted most herbicide applications and the rain this week will delay them further. Corn is anywhere from planted to about V4 in central Iowa; while most fields look great, I’ve gotten calls about a number of issues related to planting and early growth – anhydrous ammonia burn on roots, uneven emergence due to seed sitting in dry soil, uneven emergence due to soil crusting, and even some insect injury. Soybeans are anywhere from just planted to close to V1. I’ve received fewer reports of issues in soybean this year, but I have seen some herbicide injury from splashing and soil crusting in fields as well. Some soybeans planted into large cover crops really looked like they could use some rainfall last week, so the rain early this week is great for them. The biggest news of the last week or so is that PRE herbicides seem to be breaking down very quickly in corn fields and it is time to spray the POST in many fields. Keep scouting fields for early insect feeding (like black cutworms and bean leaf beetles) and monitor fields ahead of the POST herbicide application and in the 5-10 days after to make sure it actually controlled your weeds. Most phone calls in the last week were about crop emergence, non-insect pest issues (deer, squirrels – this resource from Purdue is great!), herbicide injured crops, and herbicide options for particular weeds.”
Rebecca Vittetoe (Region 8):
Iowa, Jefferson, Keokuk, Poweshiek, Washington, Johnson counties
“The week of May 19 was a warm and dry week, which allowed many to wrap up planting. Some of the earlier planted fields were sidedressed with nitrogen. The windy conditions made it more challenging to get herbicide applications made, especially later in the week. Corn ranges from recently planted to V4, not quite V5, and soybeans range from recently planted to almost V1. The big concern last week was soil crusting in fields and the potential need to replant, particularly with soybeans, due to soil crusting. PRE herbicides, especially in the earlier planted fields, are starting to break down, and more weeds are coming through. Many fields will be ready for a POST herbicide application after we dry out from the rain this week. Remember to double-check crop growth stages with the herbicide products planned for the POST application. Also, continue to scout fields for insect pests like black cutworm, true armyworm, and bean leaf beetles. On the forage side, quite a few folks took advantage of the dry weather and low humidity to take their first cutting of alfalfa. Calls or questions in the last week were mainly about stand assessments, weed ID, wildlife damage (ground squirrels and geese) and herbicide considerations..”
Virgil Schmitt (Region 9):
Cedar, Clinton, Des Moines, Henry, Jackson, Lee, Louisa, Muscatine, Scott counties
“Most of the area I cover received no rainfall during the last week. Where it did rain, it was very minimal. In general, field work progressed well last week. I would guess that 90+% of the corn is planted. Most corn is V2 to V4 and generally looks good. I would guess that 90+% of the soybeans are planted. Soybeans are mostly VE to VC and generally look good. Hay and pastures look good and the harvest of first cutting hay progressed rapidly. I would guess that about 50% of the first cutting harvest has been completed. Wind made keeping windrows in place for baling a challenge. (Also, the wind created sandstorms in some of the sandy areas.) Smooth bromegrass and orchard grass are heading out. Calls last week mostly centered around nitrogen injury to corn and corn leafing out underground.”
Aaron Saeugling (Region 10):
Adair, Adams, Cass, Clarke, Decatur, East Pottawattamie, Fremont, Mills, Montgomery, Page, Ringgold, Taylor, Union, West Pottawattamie counties
“Corn planting has wrapped up in most locations. Emerged corn is looking good with the taller corn in the V4 stage and growing rapidly with warm weather last week. Welcome rain in most portions of SW Iowa have helped dry soil conditions and improved emergence for field planted in marginal conditions. Soybean planting is also wrapped up, except for fields where rye is harvested for silage. Weed control is the big activity this past week. Post-emerge spraying on corn and some early post on early planted soybeans also had farmers busy. First cutting hay has started with low humidity and dry windy conditions should have allowed for good hay making where we missed showers. Pastures are in good condition with cows moving to grass turnout.”
Logan McCrea (Region 11):
Appanoose, Davis, Lucas, Mahaska, Marion, Monroe, Van Buren, Wapello, Wayne counties
“Recent weather over the past couple of weeks has allowed farmers to complete a large chunk of their spring field work, with corn and soybean planting relatively wrapped up minus some planned delayed planting situations. Lots of first cutting alfalfa was harvested this past week, with tremendous weather for it. Forages will benefit greatly from the rainfall coming this week, with this week appearing to be much cooler and wetter than the past few weeks. The moisture is needed and will be much appreciated by producers in the area. Corn stages range from VE to V4 and soybean stages range from VE to V1, depending upon planting dates. Insect activity hasn't been at high levels of pressure yet, although if you look hard enough you can find some levels of activity for alfalfa weevil/black cutworm/etc. in fields. Recent calls have been centered around herbicide injury, weed ID/pasture weed management, and first cutting timing for hay crops.”
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- Field Agronomist in EC/SE Iowa