From our Weed Science Team
Note from Sarah: As a drive the insect scouting loop in Paulding County, I am noticing many fields invested with water hemp which is a great concern in weed control. Other things to make note of are barnyard grass, velvet leaf , marestail and volunteer corn.
By: Mark Loux
There are plenty of fields with late-season weed problems this year. Weeds that come through the crop canopy late may be small or spindly or sparse enough to be handled easily by a combine. Other fields can benefit from a preharvest herbicide treatment to kill/dissociate weeds, which makes harvesting easier and can reduce weed seed production and foreign matter in harvested grain. Information on preharvest herbicide treatments for field corn and soybeans can be found in the “Weed Control Guide for Ohio, Indiana, and Illinois”, at the end of those crop sections (pages 75 and 146 of the 2022 edition). Products listed for corn include Aim, glyphosate, 2,4-D, and paraquat, and for soybeans include Aim, dicamba, paraquat, glyphosate, and Sharpen. Keep in mind that Aim and Sharpen have relatively narrow spectrums of activity, and will be less effective than the others across a broad range of weed species (i.e. make sure the target weed is something that they actually control). Continue reading
By: Christine Gelley, Agriculture and Natural Resources Educator, Noble County OSU Extension;
The time has come for Canada thistle flowers to line the roadways and begin to bud in pastures and hayfields. The lavender-colored aggregate flowers that develop into fluffy seed are one of the most distinguishing characteristics of the plant. They are easy to find blooming from June through August. If it wasn’t such an unpleasant plant to encounter, I might call it pretty. It isn’t poisonous, thank goodness, but it certainly is troublesome. Some animals will tolerate it while grazing, but most will avoid it while it is growing or sort it out of a hay bale. Continue reading
I wanted to share the upcoming events in NW Ohio Extension related to Agriculture to get those events on your calendar. Here is the link https://go.osu.edu/summernwohio22 or you can download the PDF of the newsletter 2022 Summer NW Ohio Newsletter PDF Version. I hope to see you at these summer events.
Due to the weather, last week’s Weed University has been rescheduled and we have some spots open. The rescheduled training will be held on Friday, February 18. Registration will be 9:00 – 9:15 AM with the program beginning at 9:30 AM. Pre-registration is required as we are limited due to space with the hands-on activities and required materials. The link for registration is http://go.osu.edu/22PauldingWeeds.
Join the Digital Ag Team as they dive into research results from around the state of Ohio based on the 2021 eFields report. Registration is free but required. Have you been enjoying the 2021 fields Report and are excited to learn more? Join us to learn more about the eFields program and the results we are seeing across the state.
The program will happen on Tuesday, February 1 and 8 from 9:00 AM – 10:00 AM. The format will be the same but due to participants registered different 2021 eFields reports may be discussed. CCA and CEUs will be offered.
Register at http://go.osu.edu/AgTechTues
OSU Extension invites crop producers to attend a regional 2022 Ohio Weed University on Thursday, February 3 from 9:00 a.m. to 4:00 p.m. at the Paulding County Extension Office, Large Hall, 503 Fairground Drive, Paulding, OH 45879.
This program is designed to keep agronomic producers on the cutting edge in weed control for their cropping operations. Topics addressed will include hot topics in weed control, local weed issues, biology, identification of weeds, control strategies, cover crop management in forages, and evaluating herbicides. Hands-on exercises will be included. Featured speakers will include Dr. Mark Loux, State Weed Specialist, and Alyssa Essman from The Ohio State University. This is an “in-person” event with a portion of the program being conducted virtually at the above location.
The registration fee per person is $40 and is due by February 1, 2022, at 8:00 PM.
This fee includes course materials. Paulding Weeds University Flyer – 2022. The link to the online registration is at http://go.osu.edu/22pauldingweeds. With this link, you have the opportunity to pay with a debit/credit card.
Pesticide and Certified Crop Advisor (CCA) credits will be available. If you can’t attend the Paulding County event, there are other regional events. Please see the CORN Newsletter article at https://agcrops.osu.edu/newsletter/corn-newsletter/2022-02/2022-ohio-weed-university
By Mark Loux, Ohio State University Extension herbicide specialist
The U.S. Environmental Protection Agency issued a new seven-year registration for Enlist One and Enlist Duo, valid through January 2029. Changes include a revised application cutoff for soybeans, “through R1” that replaces “up to R2” on previous labels, and the addition of a slew of spray nozzles to the approved nozzle list. The most significant change for Ohio is that, due to changes in Endangered Species information, Enlist One and Enlist Duo cannot be used in 12 Ohio counties: Athens, Butler, Fairfield, Guernsey, Hamilton, Hocking, Morgan, Muskingum, Noble, Perry, Vinton, and Washington. We contacted Corteva to see if this was likely to change anytime soon, and got no assurances of this, although the PR information they have distributed indicates it is possible.
This really couldn’t happen at a worse time for growers in these counties. We’re in the middle of an endless pandemic, a worldwide shipping fiasco, with herbicide scarcities, price increases, and parts shortages. And just when you had it worked out to use Enlist herbicides on Enlist soybeans for 2022 so you wouldn’t have to deal with dicamba, their use is no longer legal in your county. We’re trying to find something reassuring to say here, but there’s not much. We lack solid information on herbicide availability and price, and it’s a fluid situation, but it appears that glyphosate and glufosinate can be in short supply, and prices are high. Continue reading
By Mark Loux, OSU Extension
We have been screening a random sample of waterhemp populations for herbicide resistance over the past two years. Herbicides used on the screen include mesotrione, atrazine, 2,4-D, fomesafen, and metolachlor. Results of our research show that it’s possible for Ohio waterhemp populations to have some level of resistance to one, several, or all of these herbicides. Glyphosate is not included because we assume almost all populations are already resistant to this. We are also part of a regional project that has been screening for dicamba and glufosinate resistance with populations that we supply, although none has been identified to date. Continue reading
Are you looking for up-to-date weed control or fertility information before planting season? The OSU Extension Paulding County Office now has copies of the 2021 Ohio, Indiana, and Illinois Weed Control Guide and Tri-State Fertilizer Recommendations for Corn, Soybean, Wheat, and Alfalfa available for purchase.
The 2021 Ohio, Indiana, and Illinois Weed Control Guide explains the importance of weed control and gives suggestions on herbicide management strategies for corn, soybeans, small grains, and forages. Also included are special sections on marestail, Palmer amaranth, and waterhemp. An index to all tables regarding herbicides is listed on the back cover for easy navigation and quick referencing. The cost of the publication is $17.25 plus $1.25 in tax making the total for the booklet $18.50.
The updated Tri-State Fertilizer Recommendations for Corn, Soybeans, Wheat, and Alfalfa reflects changes in regional field crop production practices, including general reductions in tillage and crop rotations, greater plant populations and grain yields, new pests and diseases, and the emergence of precision soil sampling and fertilizer rate and placement technologies. The updated fertilizer recommendations aim to aid farmers in managing mineral fertilizer sources in field crop systems as judiciously and profitably as possible. The cost of the publication is $9.00 plus $.65 tax making the total for the booklet $9.65.
Both publications are available for purchase by either cash or check at the OSU Extension Paulding County Office (1425 East High Street, Suite 112, Bryan) Tuesday – Thursday from 8:30 a.m. to 4:00 p.m., no appointment necessary. To pick up an order call office associate, Katie Gorrell or email her at firstname.lastname@example.org. Please call ANR Extension Educator Sarah Noggle at (419) 399-8225 with any questions specific to the publications.
By Mark Sulc, OSU
Some hay producers have been unpleasantly surprised in the past when cressleaf groundsel infestations became evident in their hay fields in May prior to first cutting. Cressleaf groundsel in hay or silage is toxic to animals, and infested areas of the field should not be harvested and fed. Groundsel is a winter annual, emerging in late summer into fall when it develops into a rosette that overwinters. Growth restarts in spring, with stem elongation and an eventual height of up to several feet tall. The weed becomes evident in hayfields when it becomes taller than the alfalfa/grass and develops bright yellow flowers in May. The problem with passively waiting until this point to discover that the hay is infested with groundsel is that: 1) it’s too late to control it with herbicides; and 2) hay from infested areas has to be discarded instead of sold or fed, and large plant skeletons are still toxic even if herbicides were effective on them. Groundsel plants finish their life cycle in late spring, once they flower and go to seed, so it should not be a problem in subsequent cuttings. Continue reading
By Mark Loux, OSU
Herbicide options for burndown of existing weeds prior to planting of no-till wheat include glyphosate, Gramoxone, Sharpen, and dicamba. Among these, the combination of glyphosate and Sharpen probably provides the best combination of efficacy on marestail, flexibility in application timing, and residual control. Dicamba labels have the following restriction on preplant applications – “allow 10 days between application and planting for each 0.25 lb ai/A used”. A rate of 0.5 lb ai/A would therefore need to be applied at least 20 days before planting. We do not know of any 2,4-D product labels that support the use of 2,4-D prior to or at the time wheat planting. There is some risk of stand reduction and injury to wheat from applications of 2,4-D too close to the time of planting. Liberty and other glufosinate products are also not labeled for use as a burndown treatment for wheat. Sharpen should provide limited residual control of winter annuals that emerge after herbicide application, and the rate can be increased from 1 to 2 oz/A to improve the length of residual. Gramoxone should also effectively control small seedlings of marestail and other winter annuals. Be sure to use the appropriate adjuvants with any of these, and increase spray volume to 15 to 20 GPA to ensure adequate coverage with Sharpen or Gramoxone.
There are several effective postemergence herbicide treatments for wheat that can be applied in November to control these weeds, in fields where preplant burndown treatments are not used. The most effective postemergence treatments include Huskie, Quelex, or mixtures of dicamba with either Peak, tribenuron (Express, etc), or a tribenuron/thifensulfuron premix (Harmony Xtra, etc). We discourage the application of 2,4-D to emerged wheat in the fall due to the risk of injury and yield reduction.
Fall herbicide treatments have fallen off over the past several years for a couple of reasons, among them the effectiveness of new soybean trait systems for managing marestail, some generally crappy weather in late fall, and efforts to reduce input costs. We are seeing a resurgence in some weeds, such as dandelion, which respond well to fall herbicides, though. Some growers have also experienced issues with messy fields and late spring burndowns that could have been avoided with fall herbicides. It’s worth recalling the history of fall herbicide applications, which helps explain some of their benefits, especially if you have not been managing weeds or making recommendations for as long as some of us have. Continue reading
Its that time of year when some of our ugly weeds begin to make their presence known by rising above crop canopies, appearing along the side of the road, etc. I typically receive many questions about noxious weed identification, control, legal issues, and more. Below is the first page of the OSU Law Bulletin on Noxious weeds. Click here to download the complete bulletin.
By Mark Loux OSU Extension
In our windshield scouting of soybeans this year we have seen a lot of weed-free fields. This makes sense given the shift toward Xtend, LibertyLink, LLGT27, and Enlist soybeans over the past several years, which provides us with effective POST options for our major weed problems – common and giant ragweed, marestail, and waterhemp (now if we could just get rid of the baggage some of these traits carry). We are however getting many reports of late-season waterhemp as it grows through the soybeans and becomes evident. This also makes sense given that statewide we are in the midst of an overall increase in waterhemp, and continue to move up the curve in terms of the number of fields infested and the size of the infestations. Prevention and management of waterhemp and Palmer amaranth has been one of the primary goals of our state and county educational programs for half a decade or more. And one of the most important points about waterhemp and Palmer that we try to get across is their capacity for prodigious seed production – 500,000 to upwards of a million seeds per plant – and what this means for their ability to rapidly ramp up populations, infest equipment, etc. Continue reading
OSU weed scientists and ag engineers are looking for soybean fields that have populations of waterhemp or Palmer amaranth surviving into July and August (after all control with herbicides has been attempted). We have a project involving the use of a drone to identify these weeds in mid to late season when they are evident above the soybean canopy. We need fields with more than just a few surviving plants. Populations consisting of a few good patches up though a disaster are fine. Contact Mark Loux – email@example.com, 614-395-2440. Thanks in advance for your help.
There was a great deal of action last Friday in the case that vacated the registrations of XtendiMax, Engenia, and FeXapan dicamba-based products. Despite a barrage of court filings on Friday, however, nothing has changed the current legal status of the dicamba products in Ohio, and Ohio growers may use existing stocks of the products now. Still, they must end-use by June 30th, 2020.
Here’s a rundown of the orders that the Ninth Circuit Court of Appeals issued in the case last Friday:
The court denied the emergency motion that the petitioners (National Family Farm Coalition, Center for Food Safety, Center for Biological Diversity, and Pesticide Action Network North America) filed on June 13th. That motion asked the court to enforce its previous mandate to vacate the registrations, to prevent any further use of the products, and to hold the EPA in contempt for issuing the Cancellation Order the agency had made that allowed continued use of existing stocks of the products. The court did not provide its reasoning for denying the motion. Continue reading
By: Mark Loux and Bruce Ackley, OSU Extension
The maps that accompany this article show our current knowledge of waterhemp and Palmer amaranth distribution in Ohio. These are based on information from a survey of OSU Extension County Educators, along with information we had from samples submitted, direct contacts, etc. We still consider any new introductions of Palmer amaranth to be from an external source (brought in from outside Ohio) – hay or feed, infested equipment, CRP/cover/wildlife seedings. Palmer is not really spreading around the state, and as the map shows, we have had a number of introductions that were immediately remediated. The number of counties where an infestation(s) is being managed is still low, and within those counties, the outbreak occurs in only a few fields still. Waterhemp is much more widespread in Ohio and is spreading rapidly within the state from existing infestations to new areas via equipment, water, animals, etc. We do not have Ag Educators in all counties, and even where we do, infestations can occur without us knowing about them. Feel free to contact us with new information to update the maps. Continue reading
The 2019 growing season came and went and left many fields in a state of disarray heading into 2020. Many growers that were unable to plant decided to use cover crops, to reduce soil erosion and provide some weed suppression during the extended fallow period. Terminating these cover crops using the right methods at the right time will be critical to ensure timely planting and prevent the cover crops from competing with cash crops. The three main methods of cover crop termination are natural (species that winter kill), chemical, and mechanical. Cover crops may also be bailed, grazed, or harvested as silage. Most species require some sort of management decision for termination. Cover crop species, growth stage, weather, and cover cropping goals should all be considered when planning termination method and timing. These decisions require a balance between growing the cover long enough to maximize benefits and terminating in time to prevent potential penalties to the following cash crop. Continue reading