C.O.R.N. Newsletter

  1. Palmer Amaranth seed head
    Author(s): Mark Loux

    The frequency of Palmer amaranth infestations in Ohio has been holding relatively steady again into this year.  We have mostly an isolated field or patch in about 10 counties, with the exception of two small epicenters of Palmer amaranth - far southern Scioto County and an area along the Madison-Fayette County line north of Jeffersonville.  Several new infestations of Palmer amaranth in soybeans have been reported over the past several weeks though.  It was also found in a first-year hayfield, where cutting and competition from the alfalfa/grass stand will likely keep it under control in co

    Issue: 2015-27
  2. Aphids on soybean leaf, UMN Extension photo
    Author(s): Andy Michel

    As predicted, we have begun to see soybean aphids move into soybean fields over the past few weeks.  Coincidentally, this is the 3rd year in a row that we have seen aphids move in relatively late in the growing season.  Hopefully, most of our soybean are starting to mature and reaching the R6 stage, but there are some that still have a way to go due to delayed spring maturity.

    Issue: 2015-26
  3. soybean pods, photo by Rory Lewandowski
    Author(s): Laura Lindsey

    To estimate yield, four soybean yield components need to be considered: plants per acre, pods per plant, seeds per pod, and seeds per pound (seed size).  A printable worksheet to estimate soybean yield can be found by clicking here.  It is difficult to accurately predict soybean yield because of plant variability and fall weather conditions can influence seed size.  Estimates become more accurate as the growing season progresses. 

    Issue: 2015-26
  4. Sclerotinia stem rot (white mold), photo by Anne Dorrance
    Author(s): Anne Dorrance

    All of the rain during May, June, & July continues to impact the soybean crop in some areas of the state during 2015 in Ohio.  Surveys of our plots and some scouting in the lower canopy have turned up some surprises and some we expected.

    Issue: 2015-24
  5. Green Stink Bug
    Author(s): Andy Michel

    As our soybean begins to develop flowers and pods, we need to be aware of stink bugs that will begin feeding.  Although more common in the southern US, we have been noticing more stink bugs in soybean the past few years, even some fields where economic damage was seen. There are several species, including the green, the brown, the red-shouldered and the brown marmorated stink bug.  These insects have piercing/sucking mouthparts similar to aphids, and will pierce through the pod to feed on the developing seed.

    Issue: 2015-23
  6. Author(s): Mark Loux

    According to our weather guru, there is no close precedent for a summer like this in the last 100 years, and I can’t recall a year with this much mid-season rain in my almost 30 years here.  This has obviously caused immense problems with post-emergence herbicide applications.  There are many fields with large giant ragweed plants that still require treatment, should field conditions become suitable for traffic again.  Even the best herbicide treatments are not likely to completely control all of the large giant ragweed, but they can be at least partially effective.  Additional goals of her

    Issue: 2015-22
  7. Author(s): Laura Lindsey , Author(s): Anne Dorrance

    Wet weather is continuing to be a problem throughout the state, and many questions are popping up regarding late-season fungicides. 

    Issue: 2015-22
  8. Author(s): Anne Dorrance

    We have had lots of inquiries this past week on the benefit or lack-there-of from fungicide applications on soybean in Ohio.  There are several factors that I have found in the past that can influence this return on investment:   growth stage of the plant, conditions that are favorable for disease and the presence of inoculum.  Below I have outlined how these may influence the outcome for a couple of our most yield limiting late season diseases:  Sclerotinia stem rot (white mold) and frogeye leaf spot. 

    Issue: 2015-22
  9. Author(s): Steve Culman , Author(s): Ed Lentz, CCA

    Additional Authors:  Anthony Fulford, Clay Dygert,

    Issue: 2015-20
  10. Brown Spot in Soybeans
    Author(s): Anne Dorrance

    I looked at the soybean prices on Sunday – all were still less than $10/Bushel.  This price combined with yield losses due to late planting, extra expenses for additional late weed control, and flood injury really put the kibosh on all but the most guaranteed return on investment for the remainder of 2015.  Here are a few guidelines, results from our studies in Ohio that point to the best return on investment.

    Issue: 2015-18