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.
Northwest Iowa
Leah Ten Napel (Region 1): “In the past week my region of NW Iowa has received less than an inch of rainfall. For many farmers this has provided a great window of opportunity for field work. Some areas of my region are still facing ponding issues and are unable to plant or replant fields. Early planted fields are looking very healthy at this time. Some later planted crops are working through their rough phases, but I believe they will be coming out of it soon. Some herbicide issues are arising due to drift or tank contamination. We are also seeing some insect damage. Be sure to scout fields now for planter, emergence, disease or insect issues! Keeping track of these problem areas now will help us better evaluate the crop all season long.”
Gentry Sorenson (Region 2) “Rainfall across my region ranged from just over 0.2 to over 2 inches. Fieldwork this week included planting, replanting, pre and post herbicide applications and cutting and baling of hay. Replanting of areas in corn and soybean fields that had past ponding occurred in many fields this week. Sprayers were active this week spraying corn and soybean fields, placing priority on fields that did not receive a pre herbicide due to persistent rainfall. Corn growth stages range from VE-V5, and soybean growth stages range from VE-V3. Phone calls and field calls have been related to prevent plant, replanting, stand evaluations, and spray drift questions."
North Central Iowa
Angie Rieck-Hinz (Region 3): “For the week of June 3 through June 9, Northwood received 1.75 inches of rain while Webster City received only 0.27 inches of rain. On Thursday, June 6, we had sustained winds of over 40 mph with gusts over 50 mph. This caused “sandblasting” to corn in fields with very little residue, leaving behind shredded leaves and desiccated tissue. Fortunately, most corn was still V6 or smaller and the growing point was below ground. Damage to existing leaves may cause loss of those leaves, but corn should recover. Corn is V1 to V8. For all intents and purposes, soybean planting has wrapped up and most folks were afforded an opportunity to replant the potholes. Soybeans range from VE to V4. You should be scouting for soybean gall midge. Here is the distribution map. There have been many acres of hay cut and baled this past week.”
Northeast Iowa
Josh Michel (Region 5): “Last week farmers were able to take advantage of a few dry days to get back into the field. Scattered rain showers came through the early part of the week and again over the weekend. Most of the region generally received around 0.5 to 1 inch of rainfall. However, some isolated areas in Delaware and Dubuque Counties received up to 2.5 inches from a line of severe storms that came through. Most of the remaining first crop of alfalfa has been put up. Many fields have been getting sprayed for alfalfa weevils and potato leafhoppers. Pastures continue to benefit from the weekly rainfall and look good. Oats are heading out in most fields and are also looking very good at this time. Early planted corn fields can be staged up to V6, while later planted corn fields are anywhere from V1 to V3. True armyworms continue to be found feeding on young corn seedlings in a few isolated fields that previously had cereal rye. Side dressing applications and many post herbicide applications are starting to take place. Soybeans follow a similar story, with earlier planted soybeans generally around V3, while recently planted soybeans are at VC to V1. There’s been some noticeable insect feeding in some soybean fields from true armyworms and bean leaf beetles. Post herbicide applications have started in many soybean fields and will continue as the weather allows. Other field calls last week consisted of forage management, weed identification and management, insect identification and management, along with a few calls about possible pesticide drift and injury.”
Central Iowa
Meaghan Anderson (Region 7): “Central Iowa received variable rainfall in the last week, with some getting less than an inch and others receiving well over two inches. Still, we’ve had overall drier conditions between the rainfall, crop growth, and warmer temperatures that have allowed for replant crops to get filled in and herbicide applications to happen. Some of the early corn is up to about V8 and has evened out in color across many fields. The big question for many remains whether we need more nitrogen due to the wet spring, so I’m glad our new extension soil fertility specialist, Richard Roth, wrote a series of blogs on the topic. The big news in corn in the last week is the discovery of tar spot in Marshall, Tama, and Jasper counties. This is a great opportunity to get out in the field and scout corn, but don’t jump to make a fungicide application too early (we have a lot of growing season left and time to make fungicide decisions). Soybeans are up to about V3, though some are beginning to show scattered flowers and we’ll probably be at R1 in some fields by the end of the week. Many POST herbicide applications are happening in soybean. Upcoming pest issues to keep an eye out for include corn rootworm larval feeding, Japanese beetle emergence, and soybean gall midge moving from overwintering sites to soybean in Iowa. Most phone calls in the last week have been related to light green corn or herbicides and weed control, including weed ID, drift, herbicide phytotoxicity, and POST herbicide products.”
East Central, Southeast, and South-Central Iowa
Rebecca Vittetoe (Region 8): “The last week brought another relatively “dry” week with rainfall totals across my counties ranging from 0.05 to 1.3 inches. The drier conditions allowed for more field activities including putting up hay, replanting, sidedressing nitrogen, and spraying. I’ve seen corn up to the V8-V9 growth stage and soybeans up to V3. I haven’t seen any soybean fields flowering yet. Do double check crop growth stages and herbicide labels for those fields that still need their POST herbicide application. Nitrogen loss concerns, yellow or light green looking corn, herbicide injury, true armyworms, stink bug injury in corn, and weed identification were the common questions or field visits over the last week. Things to keep on your radar as we look ahead include Japanese beetle starting to emerge, corn rootworm larvae (especially in my southern counties as we getting close to the 50% of egg hatch, which occurs between 684-767 accumulated growing degree days (January 1, base 52F)), and evaluating weed control following herbicide applications.”
Virgil Schmitt (Region 9): “Rainfall during the last week in the counties I cover generally was one inch or less. Most farmers were able to wrap up any lingering corn and soybean planting and complete first cutting hay harvesting. Most corn is about V6-V8 and looks good. Post-emergence herbicide applications are occurring. Most soybeans are at V1-V4 and also look good. First cutting hay harvest is about 75% complete and was very good except for alfalfa weevil damage. Oats are headed out and looking good. Contacts last week mostly involved hay harvesting, true armyworms, herbicide injury, and corn postemergence herbicides.”
Check out the map below to find your local ISU Extension field agronomist and find their contact information here!
Rebecca Vittetoe Field Agronomist in EC Iowa
Rebecca Vittetoe is an extension field agronomist in east-central/southeast Iowa serving Iowa, Jefferson, Johnson, Keokuk, Poweshiek, and Washington counties. Vitteoe works with farmers, landowners, and ag retailers to answer agronmy-related questions. Her areas of expertise include general ...