Yellow Fields Forever

By: Joe Boggs, OSU Extension
The dichotomous nature of cressleaf groundsel (a.k.a. butterweed) (Packera glabella; syn. Senecio glabellus) tests the tolerance of lovers of native wildflowers.  On one hand, a sea of golden-yellow flowers carpeting farm fields in Ohio provides welcome relief from highway monotony.  On the other hand, upright 2 – 3′ tall plants dominating Ohio landscapes presents a weed management challenge.

Cressleaf Groundsel

Cressleaf groundsel is so-named because its lower leaves resemble watercress.  Its alternate common name of butterweed comes from its conspicuous buttery yellow flowers. Continue reading

Managing Big, Wet Cover Crops

By: Mark Loux, OSU Extension Weeds Specialist

Managing cover crops in a year like this can challenge even those with the most experience. A few suggestions regarding termination of covers:

• Increase glyphosate rates to compensate for larger size, and consider applying alone or just with Sharpen. Mixing glyphosate with other herbicides or ATS can reduce its activity on grass covers, especially when large. Herbicides that can antagonize glyphosate include 2,4-D, metribuzin, atrazine, and flumioxazin and sulfentrazone products. Sharpen has not caused a reduction in glyphosate activity on grass covers in university research. One approach would be to apply the glyphosate or glyphosate/Sharpen first, wait a few days, and then apply residual herbicides. Continue reading

Ohio Fall Weed Survey Follow-Up

By: Harold Watters, Ohio State University Extension Agronomic Systems Field Specialist

So I got some calls after our Extension Fall Weed Survey — if these are the problem weeds, then how do you deal with them?

It is becoming apparent that with the move to herbicide tolerant crops, we aren’t necessarily getting rid of all of our weeds — only 30% of our fields are weed free. Giant ragweed moved back into first place for worst weed, seen in 34% of fields overtaking marestail seen in 30% of fields. And then there is the pigweed problem — waterhemp appeared frequently, so did redroot pigweed and then there are the concerns about Palmer amaranth and its escape across Ohio.

 

Weed 2018 Ohio rank % of fields
Giant Ragweed 1 34
Marestail 2 30
Waterhemp 6 10
Redroot pigweed 10 5

Continue reading

New Dicamba Restrictions

By: Bob Hartzler, Professor of Agronomy at Iowa State University

I feel obligated to write something about EPA’s dicamba announcement, but will confess at this time I still have several questions that I’m seeking answers for.   But here are my initial thoughts regarding the new approach to dicamba management.

  1. 45 days after planting.I’m not sure if this restriction replaces the previous restriction that limited applications up to and including the R1 soybean stage.  Regardless, I see very little value to this new restriction. According to USDA-NASS Crop Progress reports, the 5-year average for Iowa soybean planting is 51% planted on May 20. Thus, applications would be allowed into July for much of Iowa’s soybean acres.  In 2017, 90% of dicamba misuse complaints to IDALS were associated with applications made after June 15. I believe a date restriction would be more appropriate, a date in mid-June would be my preference.

Continue reading

No Pigweed Left Behind

By: Mark Loux, Ohio State University Extension Weed Specialist, previously published in the C.O.R.N. newsletter

If you don’t already have to deal with waterhemp or Palmer amaranth, you don’t want it. Ask anyone who does. Neither one of these weeds is easy to manage, and both can cause substantial increases in the cost of herbicide programs, which have to be constantly changed to account for the multiple resistance that will develop over time (not “can,” “will”). Continue reading

ODA Proposes Changes to Ohio’s Noxious Weeds List

By Peggy Hall, Asst. Professor, Agricultural & Resource Law, Ohio State University

Wild carrot, Oxeye daisy, and wild mustard will no longer be prohibited noxious weeds in Ohio if the Ohio Department of Agriculture’s (ODA) revisions to the noxious weeds list become effective. ODA is proposing to remove the three plants after its five-year review of plant species considered “noxious” for purposes of Ohio law. The agency is also proposing adding these 12 species to the noxious weeds list: Continue reading

Weed Observation and Management in Ohio

By Harold Watters, Ohio State University Extension

I hear the neighbor’s combine running and the semi rolling past the house so it’s a good night to harvest late. Hopefully as everyone harvested their soybeans they were observing what weeds are out there. We did have an open canopy for an extended period into the year due to the cool, wet growing conditions. This often leads to an increased number of weeds. Our county educators have been observing soybean fields across the state this fall to see what is out there for our annual fall soybean weed survey. Continue reading