eFields Partnering with Growers to Evaluate Xyway™ Fungicide

Northern corn leaf blight symptoms

By:  Stephanie Karhoff

Preventing significant yield losses from disease is likely on the forefront of growers’ minds following the 2021 growing season. A new product in our disease management toolbox is FMC’s fungicide Xyway™ LFR®. OSU Extension eFields program is partnering with growers to conduct on-farm trials evaluating the effect of an at-plant soil application of flutriafol (Xyway) on corn health and yield. Information from this trial will be used to improve corn disease management recommendations for growers throughout the state. Continue reading

OSU Extension Williams County to Monitor Corn Pests and Pathogens

Western Bean Cutworm Trap

OSU Extension Williams County will be monitoring for Western Bean Cutworm (WBC) moths again during the 2022 growing season.

Moths are trapped by placing pheromone traps (see picture) at the edge of corn fields throughout the county, and checked on a weekly basis beginning late June and proceeding through August.

The WBC monitoring program is a state-led initiative to better understand insect populations, and develop management recommendations for growers. Each week, WBC numbers will be published in the C.O.R.N. newsletter. Williams County WBC numbers will also be published on this blog on a weekly basis. (Farm name and location is NOT shared with WBC numbers).

New this year, OSU Extension Williams County will also be collaborating with State Specialist Dr. Pierce Paul to monitor spore movement of the fungal pathogen that causes Tar spot in corn. Traps will be placed at the edge of corn fields and then analyzed by the corn pathology lab in Wooster to count the number of spores present. This will help answer the question of how this pathogen spreads and will improve Tar spot management strategies. Fields that have been affected by Tar spot in the past are preferred.

If you are interested in hosting a WBC bucket trap or Tar spot spore trap in one of your corn fields in 2022, please call ANR Educator Stephanie Karhoff at 419-636-5608 by April 1 with field location.

Low Vomitoxin Levels in Corn but Rain and Delayed Harvest Could Change this Picture

By:  Pierce Paul, Wanderson B. Moraes, Marian Luis

After walking more than 40 corn fields and sampling more than 3,500 ears, we believe that Gibberella ear rot (GER), and consequently, vomitoxin levels likely will be much lower this year than they were last fall. This is because conditions during the weeks after silking were considerably less favorable for the disease to develop and the toxin to contaminate grain this year than last year. However, as is often the case, there were a few exceptions. We found low levels of GER in (sentinel-type) plots and research fields deliberately planted with hybrids that are highly susceptible to the disease, and these plots/fields will likely yield grain with some level of vomitoxin contamination (we are still processing our samples). Averaged across 10 locations, the incidence of GER on a susceptible hybrid ranged from 10 to 20%, i.e., 1 to 2 out of every 10 ears had visual symptoms of GER, and on average, less than 5% of the surface area of affected ears showed symptoms of the disease. Continue reading

Answer your Tar Spot Questions with On-Farm Research

By:  Stephanie Karhoff

To growers’ dismay, 2021 is shaping up to be a “good” year for Tar Spot (“good” if you are a plant pathologist at least). Though the combine will have the last say on Tar Spot’s yield impact on corn fields across Williams County, it is already evident that Tar Spot has become more widespread across the county, state, and even the Corn Belt. Continue reading

“Take the Test & Beat the Pest” – Free SCN Soil Testing Available in 2021

SCN coalition what's your number logo
As part of the SCN Coalition surveillance program, free SCN testing will be available to soybean growers in Williams, Fulton, Henry, and Hillsdale (MI) Counties again in 2021.

Soybean cyst nematode (SCN), is the #1 yield-limiting soybean pathogen in the U.S. and could be “silently” robbing you of bushels. This is because SCN can cause yield reduction without any visible above-ground symptoms, like stunting or yellowing. Knowing whether SCN is present in your field(s) and to what extent impacts your soybean variety, crop rotation, and seed treatment decisions. Continue reading

Watch Vomitoxin Levels in Feed

By:  Erika Lyon, Agriculture & Natural Resources Educator, Ohio State University Extension

Reports from the field suggest that vomitoxin may be higher near tree lines around the perimeter of corn fields. Figure 1. Gibberella ear rot. Photo by the Department of Plant Pathology, North Carolina State University, Bugwood.org

High vomitoxin levels are leading to the rejection of some corn at grain elevators this year. Vomitoxin detected in corn so far is enough that at some elevators, trucks are not permitted to leave scales until a vomitoxin quick test is completed. One central Ohio elevator has been rejecting corn at 5 ppm, with estimates of 10% of corn being rejected this season. The average level of vomitoxin in corn passing through central Ohio elevators is estimated at 2 ppm. What exactly does this mean for livestock owners who use this corn as a source of feed? Continue reading

Gibberella Ear Rots Showing up in Corn: How to Tell It Apart from Other Ear Rots

By:  Pierce Paul and Felipe Dalla Lana da Silva

Ear rots differ from each other in terms of the damage they cause (their symptoms), the toxins they produce, and the specific conditions under which they develop. GER leads to grain contamination with mycotoxins, including deoxynivalenol (also known as vomitoxin), and is favored by warm, wet, or humid conditions between silk emergence (R1) and early grain development. However, it should be noted that even when conditions are not ideal for GER development, vomitoxin may still accumulate in infected ears.

A good first step for determining whether you have an ear rot problem is to walk fields between dough and black-layer, before plants start drying down, and observe the ears. The husks of affected ears usually appear partially or completely dead (dry and bleached), often with tinges of the color of the mycelium, spores, or spore-bearing structures of fungus causing the disease. Depending on the severity of the disease, the leaf attached to the base of the diseased ear (the ear leaf) may also die and droop, causing affected plants to stick out between healthy plants with normal, green ear leaves. Peel back the husk and examine suspect ears for typical ear rot symptoms. You can count the number of moldy ears out of ever 50 ears examined, at multiple locations across the field to determine the severity of the problem.

Ear rot symptoms

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Overwintering of Pathogens and Insects – What do Winter Temperatures Tell Us About Next Season?

By:  Anne Dorrance, Kelly Tilmon, Andy Michel

Frogeye leaf spot on soybeanOver the years we have developed databases of winter temperatures followed by scouting to indicate starting pathogen populations for Ohio.

Frogeye leaf spot – We have documented early infections and overwintering ability of the fungus, Cercospora sojina, that causes frogeye leaf spot. It appears that when there are less than 10 days during the months of December, January and February of less than 17 F, we have had reports of outbreaks of frogeye leaf spot.  This occurred in fields where there was a high level of inoculum at the end of the season the same or similar moderately to highly susceptible cultivar was planted into the same field again which then initiated the epidemic that much sooner.  Losses of greater than 35% in yield or very early fungicide applications were necessary. Continue reading

Frogeye Leaf Spot – Is It Worth Spraying in 2019?

By:  Anne Dorrance, Ohio State University

Frogeye leaf spot

Several reports over the last two weeks of heavy frogeye leaf spot pressure in some fields as well as low to moderate pressure in others.  This disease will continue to increase and infect new foliage as it develops on these late planted soybeans. Based on our previous research, only once (2018) in 14 years of studies did applications at the soybean growth stage R5 contribute to preserved yield.  At the R5, the leaf at the terminal is fully developed and the pods at any one of the top four nodes is fully expanded, but the seeds are just beginning to expand. Continue reading

Keep an Eye Out for Tar Spot

Tar spot of corn

Tar spot on corn. Photo: Martin Chilvers, MSU.

By:  Stephanie Karhoff

As the season progresses, keep an eye for tar spot, a new corn disease caused by the fungus Phyllachora maydis. The pathogen originates from Mexico and Central America, but has made its way to the Buckeye State.

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