Extension Update by Jenny Rees

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 9^th 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.