Monthly Archives: April 2021
Evergreen Problems Webinar will be on April 22 from 7-8:30 p.m. Please call Platte County Extension at 402-563-4901 to RSVP. They will send you the Zoom link and password. There is no fee.
Considering Carbon: opportunities and challenges webinar will be held April 21 at 11 a.m. CST. Info & registration here: https://nationalaglawcenter.org/webinars/climate21/. There is no fee.
Reminder: Household Hazardous Waste Collection April 24th for Seward (8 a.m.-Noon) and Butler (1:30-4:30 p.m.) counties.
Soybean germination and planting: When I first began Extension, research on early soybean planting was just beginning. At the time, I hadn’t thought about planting soybean at the same time as corn, or even before corn. Soybean genetics and seed treatment improvements have allowed for this. Our recommendation for increased yield is to aim for planting the last few weeks of April if conditions are right, use a seed treatment, and plant 1.75-2″ deep. It seems like each year during planting season, we experience 1) soil temps in the mid-40’s with solid soil conditions and on a warming trend and 2) the potential for cold snaps with cold rains/snow after planting. What should one do and what’s the time-frame for risk of chilling injury?
For soybean, and corn for that matter, I’m not as concerned about #1 if the soil is fit and proper seeding depth (2”) is maintained. For #2, if the soil conditions are right and there’s at least 24 hours before a cold snap, consider planting beans instead of corn. That’s because soybean imbibes (takes up) water more quickly than corn. Once that imbibitional period is completed, the risk of chilling injury also ends. The seed can then remain (in osmotic phase) at cooler soil temperatures for a period of time in a sort of ‘dormant state’, until warmer temperatures return for continued seedling development.
In March 2021, Dr. Jim Specht and I began indoor and outdoor demonstrations. To be clear, we’re not recommending planting soybean in March in Nebraska. And, the point of these studies wasn’t to encourage increasing risk of pushing planting prior to cold snaps. I’m grateful for conditions like this year that make the decision to not plant easy when we know it’s staying cold with precipitation in the forecast. Our demonstrations just provided time looking at windows of 40-50F soil temps and increasing/decreasing trends. Soybeans are just beginning emergence from the March 10 planting in York. Soil temps in soybean and corn residue and living rye cover crop have been monitored since then and can be seen in an article at cropwatch.unl.edu. The soil under rye cover was 1-5 degrees cooler than under corn residue which was 1-2 degrees cooler than under soy residue.
We used coolers at 60F and 36F at the York Co. Fairgrounds to conduct an indoor experiment, explained in more detail at cropwatch.unl.edu. Enough trays were planted with soybean and corn seed so they could be switched between the coolers every 2 and then 12 hours for a total of two days. We didn’t have space for replications. All trays were removed to my house after 72 hours. They were kept at 50F for 9 days (which in many cases, early planted soybean do set in the soil for a period of time before emergence). Then they were kept at 60F soil temp with emergence counted each day until termination April 8. In the soybean, similar percent emergence was found in the 60F control; and where soybeans were at 60F for 8, 10, 12 and 48 hours before switching to 36F. This showed that we no longer saw reduced emergence upon 8 hours prior to a cold snap (in this non-replicated experiment). This potential 8 hour critical period has been within the time-frame of published research studies and non-published field observations.
The 36F to 60F switch showed that a warming trend in the first 2-6 hours led to greater emergence. We don’t recommend planting into soils at 36F, but it served as a nice low extreme. We would anticipate the emergence would improve if the soil temp was 40F or mid-40’s with a warming trend.
What does this mean? If soil conditions are right for planting and seed is planted around 2” deep with a seed treatment, I’m not as concerned about planting soybean or corn at 45F soil into a warming trend. For planting prior to cold snaps, if one chooses to do this, we say aim for at least 24 hours for soybeans and 48 hours for corn. We know not every soybean field is completely planted at 24 hours prior to a cold snap, so to me, this gives some insight why we’ve seen fields, including two on-farm research ones in Seward county last year, still have 86% emergence prior to snow falling eight hours later. Also key is when the beans will emerge compared to frost potential. If the beans are in the ground or have cotyledons exposed, we haven’t observed a need to replant due to frost damage thus far. It’s when the hypocotyl hook is at the soil line that can result in replant potential. Thanks to York Co. Ag Society for use of their coolers, Jerry Stahr for use of his field, Jed Erickson for providing the corn and soybean seed, and Dr. Jim Specht for his help in spite of being retired!
Household Hazardous Waste Clean-Up will be held at four times and locations for residents of Polk, York, Butler, and Seward counties. These clean-ups are funded by Environmental Trust grants with Four Corners Health Dept. and various sponsoring organizations overseeing the collection at the locations.
The collections will occur:
- Polk Co.: Saturday, April 17 from 8:00 a.m. – 11:00 a.m., Polk County Fairgrounds, Osceola
- York Co.: Saturday, April 17 from 1:00pm – 4:00pm at the York Landfill, 1214 Road 15
- Seward Co.: Saturday, April 24 from 8:00am – 12:00 p.m. at City of Seward Wastewater Plant Parking Lot – 1040 S Columbia
- Butler Co.: Saturday, April 24 from 1:30pm – 4:30pm at Butler County Fairgrounds, 62 L Street, David City – North Entrance
On the specific date and time, residents of that county are welcome to bring their residential household hazardous waste in boxes. Paint in one box and other materials in a separate box. If you are not sure what something is, keep it away from other materials.
Acceptable Materials (quantities of more than 5 gallons cannot be accepted): Acids, Antifreeze, Banned Materials (chlordane, DDT, etc), Cyanide, Fertilizers (yard chemicals), Flammables, Gasoline and Oil (in small quantities), Lead Acid Batteries, Mercury and Mercury-Related Materials, All Paint and Paint-Related Materials (stains, varnish, etc), Poisons, Pesticides, Florescent Bulbs (please do not tape together)
Non-Acceptable Materials: Empty/Dried Out Paint Cans (these can go directly into your regular trash), Tires, Farm Chemicals, Electronics, Medical Sharps, Recyclables.
IN SEWARD COUNTY ONLY: They’re also additional collections at the same date/time: Scrap Metal & Appliances $5 per appliance or load of metal. Electronics Recycling: $10 – all LCD monitors; $20 – CRT (glass tube) monitors or tv’s up to 25″; $30 – TV’s 27″ and up; $40 – Large wooden projection TV’s.
Soil Temperature information for planting and applying pre-emergence herbicides can be found at: https://cropwatch.unl.edu/soiltemperature.
Crabgrass Preventer timing: Crabgrass germinates when soil temperatures are maintained at 55F for 5-7 consecutive days. We’re getting closer to this. You can watch the CropWatch soil temperature maps at the link listed above. You can also use a meat thermometer (that you dedicate to only taking soil temperature!) for your own lawn situation at a 2-4” depth. Typically, towards the end of April/beginning of May is a good time for the first application, but it will vary by year. When they’re applied too early, they can move out of the zone where the crabgrass seed is germinating. Would also recommend that you consider splitting your crabgrass herbicide application. Apply half of the highest labeled rate when soil temps warm and the other half 6-8 weeks later. Often there’s a flush of crabgrass later in the season and splitting the application can help with that. It’s helpful for the products to be watered in within 24 hours for best results.
Pastures and annual grass control: Have looked at several smaller pastures (often grazed by horses & hayed) that have issues with foxtail. Foxtail tends to emerge when soil temps are sustained around 60F, so using a pre-emergent herbicide such as Prowl H20® can help in addition to grazing management. There’s a good article in this week’s CropWatch regarding annual grass weed control for alfalfa and pastures at: https://go.unl.edu/nzmy.
Planting Considerations: In an article last year at this link https://jenreesources.com/2020/04/12/jenrees-4-12-20/, I shared about planting considerations. I don’t have anything new to add to this, so you can check that out if you’re interested. Next week will share results of a soybean and corn germination/emergence experiment I’ve been working on since Mar. 10.
Purple flowering henbit is blooming right now. Spring has officially sprung. The crabapples and flowering pears are nearing full bloom. Tulips and daffodils are starting their flower show. Henbit and dandelions are looking gorgeous. Are the last two not quite the kinds of spring flowers you want in your landscape? If so, there are some […]Henbit, Crabgrass, & Ground Ivy… Oh My! — Husker Hort
Hope you had a blessed Easter! For me, it was an extra blessing to worship in person and be with family this year! This week sharing on a variety of questions I’ve received.
Private Pesticide Certification/Recertification: for those still needing pesticide certification:
- Easiest option: attend a Zoom training being held this week on April 9th at 9:00 a.m. You can register at the following site: https://go.unl.edu/patapril9. You will receive a zoom link to attend that training. The materials and payment will occur at the local county Extension office of your choice. Cost is $50.
- Online pesticide training: This is self-paced with quizzes. You can register and pay online here: https://web.cvent.com/event/4efa4d41-c770-4a78-99d7-4c4ea75d45ae/summary. Cost is $50. If you have bad bandwidth or have difficulty with computers, please call your local Extension educator.
2021 Nebraska farm real estate survey can be found here: https://go.unl.edu/9exp.
Emerald Ash Borer Map: We don’t recommend treatment for ash trees until your tree is within a 15 mile radius of where emerald ash borer has been confirmed. Right now, most of Seward county is in the treatment zone but York county is not. We also only recommend considering treating high value trees that don’t have obvious health issues. You can view a map of the suggested treatment areas at: https://nfs.unl.edu/documents/EAB/EABmap1-22-21.png. More information can be found at: https://nfs.unl.edu/eab-faq.
Small Grains and Jointing: The jointing stage of wheat, rye, and triticale is when the growing point comes above ground. This is a critical stage when taking these crops for grain, as growth regulator herbicides, particularly dicamba, can cause injury to the stem base (causing wheat to grow prostrate) and heads of the plants (emerge deformed) if they’re applied. The best way to check for jointing is to pull up a plant by the roots, slit open the main (thickest) stem from the base up, and see if you can see the developing head or not. I was seeing jointing occurring in earliest planted rye in York Co. last Thursday. 2,4-D and MCPA are labeled from full tillering till prior to boot stage but I’ve still seen 2,4-D at jointing to cause wheat to grow prostrate at times. K-State shares in spite of this, they don’t typically see yield loss in these situations when 2,4-D was applied.
Cover crop termination: University of Missouri recently released results of a multi-state study funded by the United Soybean Board looking at herbicide options for cover crop termination. Control of cereal rye and wheat used for cover crops was best with glyphosate alone or in combination with 2,4-D, dicamba, Sharpen, or Select. For legume cover crops, glyphosate, gramoxone, and liberty were all similarly effective, particularly in combination with 2,4-D, dicamba, or Sharpen. Brassica species weren’t reviewed in this study, but there are ratings available in the front section of the 2021 weed guide which show highest control ratings with glyphosate + 2,4-D or dicamba. The full study results can be found here: https://ipm.missouri.edu/IPCM/2020/3/coverCropTermination-KB/.
Seed corn maggots: Something on my mind is the potential for seed corn maggot pressure this year. They tend to be a problem when fields recently had manure applied or have green plant material, like cover crops, that have been incorporated into the soil within two weeks of planting the cash crop. But we’ve also seen them when the covers or manure haven’t been incorporated. The past few years we’ve seen increased seed corn maggot damage to soybeans, particularly when planted into a field that had a brassica cover crop such as turnips, radishes, and forage collards. I’ve rarely seen damage warrant replanting soybean. There’s no rescue treatments. Insecticidal seed treatments often provide protection and in-furrow insecticides can provide additional preventive protection for fields with a history of seed corn maggot damage. Extension entomologists also recommend to avoid planting during peak fly emergence which occurs when 354, 1080, and 1800 GDD have accumulated since Jan. 1 (using a base temp of 39F for the calculation), but this may not always be feasible.