C.O.R.N. Newsletter: 2022 - 30
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Sudden Death Syndrome (SDS) Or Brown Stem Rot (BSR)? That is the question!
In August we started finding soybean diseases in Ohio. Recently, several fields in Ohio have been showing foliar symptoms (Fig. 1) very similar to those caused by sudden death syndrome (SDS).
SDS is caused by the fungal pathogen Fusarium virguliforme. This species is the most prevalent in the region, however, other Fusarium species can cause SDS. SDS above-ground symptoms can be confused with those produced by a different fungus (Cadophora gregata) that causes brown stem rot (BSR). To distinguish SDS from BSR, symptomatic plants should be dug out and stem cut open longitudinally. SDS-infected plants have white, healthy-looking pith, while BSR-infected plants present brown discoloration of the pith. Moreover, fields with severe SDS symptoms can also have high levels of soybean cyst nematode (SCN). WATCH THIS VIDEO ON HOW TO DISTINGUISH SDS FROM BSR.
If you suspect to have SDS, we encourage you to submit a sample to the Soybean Pathology and Nematology Laboratory in the Department of Plant Pathology at The Ohio State University in Columbus (see address below). We will confirm if it is SDS or BSR; additionally, if it is SDS, we want to determine what Fusarium species is the causal agent. To submit samples, dig out three to five symptomatic plants (including roots), placed them in a plastic bag, and submit them to our lab. Do not hesitate to contact your extension educator or us if you have any questions.
We can help diagnose soybean diseases with you!
You are welcome to submit your samples to the address below. Contact us if you have any questions. Send your samples to:
OSU Soybean Pathology and Nematology Lab
Attn: Horacio Lopez-Nicora, Ph.D.
110 Kottman Hall
2021 Coffey Rd.
Columbus, Ohio 43210
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Late-season waterhemp and Palmer amaranth scouting resources
Waterhemp and Palmer amaranth plants that have escaped POST applications or emerged after are now starting to develop mature seed. These plants can produce upwards of one million seeds per plant in certain situations. When it comes to the management of these weeds, the best offense is a good defense. Anything we can do from now through harvest to prevent seed from being deposited into the soil seed bank will pay dividends down the road. At this point in the season there are limited options for control beyond scouting and hand pulling. Just a few plants left in the field can lead to a total infestation within a few years. Viability of waterhemp and Palmer amaranth seed is greatly reduced after 3-5 years. Some diligence over a couple of growing seasons can drastically reduce populations. Aside from tremendous seed production, fast growth rates, and lengthy emergence windows, what makes us most nervous about these weeds is their propensity to develop herbicide resistance. In other states, waterhemp has exhibited the ability to resist up to seven different herbicide sites of action, and Palmer amaranth can now resist up to nine. Resistance to more than one site of action within a single population is not uncommon. Metabolic herbicide resistance may increase the prevalence of populations with resistance to multiple herbicide groups. To date, Ohio seems to be a bit behind states to the south and west in terms of resistance issues, though experience would tell us it's only a matter of time. The status of herbicide resistance in Ohio waterhemp populations was covered in this article.
OSU weed science has a plethora of resources that can be helpful for scouting, including a pigweed ID guide, pigweed management fact sheet, and YouTube video that covers assessment for seed maturity. More helpful information on the management of pigweeds can be found on the OSU weed science website.
Below are some guidelines from Dr. Mark Loux for late-season scouting from the 2018 newsletter on this topic:
“We recommend the following as we progress from now through crop harvest:
- Take some time now into late summer to scout fields, even if it’s from the road or field edge with a pair of binoculars. This would be a good time to have a friend with a drone that provides real-time video, or your own personal satellite. Scouting from the road is applicable mostly to soybean fields, since corn will often hide weed infestations.
- Walk into the field to check out any weeds that could be Palmer amaranth, waterhemp, or are otherwise mysterious. If you need help with identification, send photos to us or pull plants and take them to someone who can identify them. Palmer and waterhemp are considerably different in appearance than giant ragweed and marestail, the most common late-season offenders.
- Where the presence of Palmer amaranth or waterhemp is confirmed, check to see whether plants have mature seed (in Palmer infestations these are the rough female seedheads), by shaking/crushing parts of the seedhead into your hand or other surface that will provide contrast. Mature seed will be small and very dark.
- Plants without mature seed should be cut off just below the soil surface, and ideally removed from the field and burned or composted. Plants with mature seed should be cut off and bagged (at least the seedheads) and removed from the field, or removed via any other method that prevents seed dispersal through the field.
- If the Palmer amaranth or waterhemp population is too dense to remove from the field, some decisions need to be made about whether or how to mow or harvest. Harvesting through patches or infested fields will result in further spread throughout the field and also contamination of the combine with weed seed that can then be dispersed in other fields. So consider: 1) not harvesting areas of the field infested with Palmer amaranth or waterhemp, and instead mowing several times to prevent seed production, and 2) harvesting the infested field(s) after all other fields have been harvested, and cleaning the combine thoroughly before further use. This also applies to any infestations that are discovered while harvesting.
- Scout field borders and adjacent roadsides, areas that flood or receive manure application, and also CREP/wildlife area seedings. The latter can become infested due to contaminated seed produced in states where Palmer amaranth and waterhemp are endemic and not considered noxious. Reminder - ODA will test any seed used for these purposes for the presence of Palmer amaranth.”
Feel free to reach out to Alyssa Essman (Essman.42@osu.edu, 614-247-5810) for questions regarding this topic or other concerns related to the identification and control of weeds.
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Farm Science Review Agronomy College Sept 13
Ohio State University Extension and the Ohio AgriBusiness Association will again partner to hold the Farm Science Review Agronomy College on Sept. 13. The event is designed to educate agronomists, Certified Crop Advisers, custom applicators, and farmers on current agronomy issues.
The full-day event features time with OSU Extension staff in the field at the small agronomy plots and larger demonstration field on the east side of the grounds. Breakout session topics will address the challenges of the 2022 growing season and the opportunities moving into 2023 and beyond.
Registration opens at 8:30 a.m. and the program will conclude by 4 pm. Participants will rotate between sessions throughout the day. Sessions are listed below and will be presented at various times throughout the day. Each session will be 60 minutes in length. ODA Pesticide Credits have been requested and CCA credits will be offered. Cost is $120 and includes lunch, materials, and credits. Location is the Molly Caren Ag Center (site of Farm Science Review): 135 St. Rt. 38 NE, London, Ohio 43140. Enter off US Rt 40 through the parking lot and park along the fence. Head to the tent in the Agronomy plot area to register.
Soybean Cyst Nematode and Other Soybean Diseases
Horacio Lopez-Nicora, OSU Assistant Professor, Plant Pathology
CCA: 1 PM; ODA Commercial: 2A
Gain an understanding of the biology and epidemiology of soybean cyst nematode and other important soybean pathogens. Discuss various strategies for scouting fields, collecting plant and soil samples, and diagnosing soybean diseases. Review updates on basic soybean disease management strategies including host resistance, fungicide application, and cultural practices and where to submit soybean and soil samples for disease diagnostics and management recommendations.
Sprayer Clean Out a Necessary Step Between Herbicides and More
Jason Hartschuh, OSU Extension Educator, Crawford County and Stephanie Karhoff, OSU Extension Field Specialist, Agronomic Systems
CCA: 1 PM; ODA Commercial: CORE
Herbicide residue in the sprayer is often thought of as a problem right after switching active ingredients but can also cause challenges in random areas of the field as residue comes loose from the sprayer. We will discuss methods to better clean out your sprayers and work with your clientele on making sure their sprayers don’t have herbicide residue carry over.
Drone Application of Crop Protection Products
Alan Leininger, OSU Extension ANR Educator, Henry County and John Fulton, Extension Specialist, OSU
CCA: 1 CM; ODA Commercial: 1
Receive current information on drone spray technology and recent advances in this new technology for applying crop protection products. Drone component needs of software and hardware to operate will be discussed, along with current regulations. General operation and experiences will be shared. A demonstration will also be performed for participants.
Crop Input Costs & Margins Outlook and Implications for Farmland Rents and Values
Barry Ward, Leader - Production Business Management, OSU CFAES
CCA: 1 CM
A review of select crop inputs and potential cost change along with enterprise budget scenarios for ’22 and ’23 crop years. Will discuss changes in farmland values and cash rents in ’22 and prospects for ’23.
Corn Diseases & Issues 2022-2023
Pierce Paul, Plant Pathologist - OSU
CCA: 1 PM; ODA Commercial: 2CAfter this varied weather year, we will look at midseason disease occurrences and management as we close out the crop year. Also, for what should we give consideration in 2023?
Agriculture’s Push to Automation and Precision
Scott Shearer, Professor & Chair – Food, Agricultural and Biological Engineering, OSU
CCA: 1 Precision Ag
Insights on crop care with agriculture’s push to automation, precision opportunities, and honing-in on targeted weed control for overall crop health and success.
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Weather Update: Average Start to Fall
Summary
Climatological summer (June-August) has come to an end and all eyes are now on harvest season. Overall, the summer of 2022 was average temperaturewise, with most of state seeing near to above average precipitation. The driest areas occurred over west central and northeast Ohio.
Over the last 30 days, precipitation has been plentiful for much of the state, running more than 200% of normal across countes near the Ohio River (Figure 1). CoCoRaHS observations for the month show numerous sites in central and southwest Ohio coming in with 6-9 inches of rain, while locations in Darke, Shelby, and Miami Counties have only picked up 2 inches over the last 30 days. This wet pattern has kept extreme heat in check, with temperatures running about average for August. For the latest up-to-date conditions, seasonal outlooks, and monthly climate summaries, please visit the State Climate Office of Ohio.
Forecast
The slow moving frontal boundary that kept heavy downpours scattered across the region this past weekend, will start to move to the east on Wednesday. Improving conditions are expected for Thursday and Friday, with plenty of sunshine and highs in the mid 70s to low 80s across the state. The next cold front is expected to move into the area this weekend, bringing with it scattered showers and storms. The Weather Prediction Center is forecasting 0.25-1.0 inch of rain over the next 7 days (Figure 2).
The Climate Prediction Center’s 6–10-day outlook for the period of September 12-16, 2022 and the 16-Day Rainfall Outlook from NOAA/NWS/Ohio River Forecast Center show near to below average temperatures and near average precipitation are expected (Figure 3). Climate averages include a high-temperature range of 77-81°F, a low-temperature range of 56-60°F, and average weekly total precipitation of 0.70-0.85 inches.
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Do I Really Need to Wait for the Fly-Free Date? Wheat Planting Date and Other Management Considerations for Fall 2022
Now that we’ve entered September, wheat planting is just around the corner. It can be tempting to plant wheat before your county’s Hessian fly-safe date (Figure 1); however, the best time to plant wheat is the 10-day period starting the day after the fly-safe date. Planting before the fly-safe date increases the risk of insect and disease problems including Hessian fly and aphids carrying Barley Yellow Dwarf Virus. Long-term averages shown in the Ohio Agronomy Guide indicate that yields are highest when wheat is planted within 10 days of the Fly Safe Date (Figure 2).
Right now, we still believe the best time to plant is within the 10-day period starting the day after the fly-safe date. But keep in mind that the Hessian fly-safe dates were calculated decades ago when average fall temperatures were cooler. Due to changes in fall weather, we are in the process of re-evaluating wheat planting dates with funding from Ohio Corn and Wheat. Last year, we conducted a wheat planting date study in Wood County and Clark County, Ohio. In Wood County, we planted 6 days prior to the fly-safe Date and 6, 29, and 48 days after the fly-safe date (Figure 3). Statistically, there was no difference in wheat yield for the first three planting dates (September 17 through October 22). In Clark County, we planted 13, 23, and 37 days after the fly-safe date (October 12-November 5), and grain yield was statistically the same across all three planting dates. We always need to be careful interpreting one year of data; however, our first-year data indicate that planting prior to the fly-safe date had no yield advantage. And, interestingly, planting 3-4 weeks after the fly-safe date had only a small effect on wheat yield. When freezing weather is delayed until November or early December, the impact of planting date is less. In an on-farm study in Fulton County (2019-2020 growing season), planting 11 days prior to the Fly Safe Date had no yield advantage over planting on the Fly Safe Date (https://kx-files-public.s3.us-east-2.amazonaws.com/efields-reports/2020_WheatPlantingDate_Fulton2.pdf).
Here are some other key management strategies for this fall:
- Select high-yielding varieties with high test weight, good straw strength, and adequate disease resistance. Do not jeopardize your investment by planting anything but the best yielding varieties that also have resistance to the important diseases in your area. Depending on your area of the state, you may need good resistance to powdery mildew, Stagonospora leaf blotch, and/or leaf rust. Avoid varieties with susceptibility to Fusarium head scab. Plant seed that has been properly cleaned to remove shriveled kernels and treated with a fungicide seed treatment to control seed-borne diseases. The 2022 Ohio Wheat Performance Test results can be found at: https://ohiocroptest.cfaes.osu.edu/wheattrials/
- Optimum seeding rates are between 1.2 and 1.6 million seeds/acre. For drills with 7.5-inch row spacing this is about 18 to 24 seeds per foot of row. When wheat is planted on time, actual seeding rate has little effect on yield, but high seeding rates (above 30 seeds per foot of row) increase lodging and risk of severe powdery mildew development next spring.
- Planting depth is critical for tiller development and winter survival. Plant seed 1.5 inches deep and make sure planting depth is uniform across the field. No-till wheat seeded into soybean stubble is ideal, but make sure the soybean residue is uniformly spread over the surface of the ground. Shallow planting is the main cause of low tiller numbers and poor winter survival due to heaving and freezing injury. Remember, you cannot compensate for a poor planting job by planting more seeds; it just costs more money.
- Follow the Tri-State Fertilizer Recommendations for Corn, Soybeans, Wheat, and Alfalfa (https://agcrops.osu.edu/FertilityResources/tri-state_info).
Apply 20 to 30 lb of actual nitrogen per acre at planting to promote fall tiller development. A soil test should be completed to determine phosphorus and potassium needs. Wheat requires more phosphorus than corn or soybean, and soil test levels should be maintained between 30-50 ppm (Mehlich-3 P) for optimum production (Table 1). Do not add any phosphorus if soil test levels are higher than 50 ppm.
Table 1. Wheat phosphorus recommendations from the Tri-State Fertilizer Recommendations for Corn, Soybeans, Wheat, and Alfalfa.
Soil potassium should be maintained at levels of 100-130 and 120-170 ppm (Mehlich-3 K) on sandy soils (CEC < 5 meq/100 g) and loam/clay soils (CEC > 6 meq/100 g), respectively. If potassium levels are low, apply K2O fertilizer at planting, depending on soil CEC and yield potential (Table 2).
Table 2. Wheat potassium recommendations from the Tri-State Fertilizer Recommendations for Corn, Soybeans, Wheat, and Alfalfa.
Soil pH should be between 6.3 and 7.0. In Ohio, limed soils usually have adequate calcium and magnesium.
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Lep Monitoring Update: FAW Trapping Continues
Fall Armyworm
The majority of counties monitoring for FAW had low trap numbers from August 29th through September 4th with the exception of Lucas, Sandusky and Paulding counties which reported averages of 30, 20.7, and 8.7 moths, respectively (Figure 1). The overall statewide average for FAW was up slightly from the previous week with an average of 4.5 moths per trap (3.9 last week). We will continue monitoring and reporting FAW numbers in Ohio through the end of September.
Fall Armyworm Moth Map
August 29 – September 4, 2022
Figure 1. Average fall armyworm (FAW) moths captured from August 29th through September 4th. The large number indicates the average moth count for the week and the small number in parentheses is the total traps set up in the county.
Thank you to the following individuals and Educators for placing and monitoring traps in your counties; Amy Raudenbush, Suranga Basnagala, Kyle Akred, Mark Badertscher, Lee Beers, Nick Eckel, Allen Gahler, Andrew Holden, Ed Lentz, David Marrison, Clifton Martin, Sarah Noggle, Richard Purdin, Eric Richer, Clint Schroeder, Frank Thayer, Cindy Wallace, Curtis Young, Chris Zoller, Andy Michel and Kelley Tilmon.
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Seed testing for cover crops to meet germination and purity requirements
Seed quality is key to establishing a good crop (or cover crop). Earlier this year, the Ohio Seed Improvement Association seed test laboratory closed. However, if you need your cover crop or wheat seed tested this fall, some alternatives include the Illinois Crop Improvement Association, Indiana Crop Improvement Association, and Michigan Crop Improvement Association. Seed lot samples can also be sent to the Ohio Department of Agriculture for seed testing, and a farmer may be eligible to receive up to three free tests if sent in between June and December.
Some of the critical components of seed quality are percent germination, mechanical analysis for purity (% other crops, % inert, and % weeds), and a listing of noxious weeds identified by scientific/common name and quantity found. Commercial or certified seed used for cover crops should have a seed tag that shows variety and the seed quality measurements above. However, if the seed is sourced from out of state, the noxious weeds listed (or NOT listed) on the tag by name may differ from the Ohio noxious weed seed list.
Only the noxious weeds for the state where the seed was originally going to be sold are required to be listed on the tag by name and quantity (Federal Seed Act, part 201.16). Each state determines which species are included on this list, and can differ from state to state. Additionally, selecting only the “Noxious Weed Exam” if an out-of-state laboratory is used may only screen the lot for the noxious weed list of the state where the lab is located. For example, a seed lot tested in Illinois for a “Noxious Weed Exam” may only screen the seed lot for the noxious weed list for Illinois.
Ordering the “all-state noxious weed exam” ensures that the lot is screened for the weeds on Ohio’s list as well as the other states. This test would screen the seed sample supplied for the weeds contained in this list, and would help to meet requirements of participating in some governmental programs (i.e. H2Ohio) where the lot undergoes an evaluation for Ohio’s noxious weed seed. Only 1.1-1.2 lbs of seed is needed for testing, but it is critical the sample is representative of the lot to ensure quality test results. Use of a sampling probe/bag trier (image) can help with collection of uniform samples, and different sizes are available.
Saved seed for wheat or cover crop planting (if allowed for that species/variety) should be tested for germination (at minimum) to help farmers dial in seeding rates to ensure good cover crop establishment this fall. Also, farmers may need to have a noxious weed exam conducted to ensure seeding a cover crop won’t bring unwanted weeds with it.
Crop Observation and Recommendation Network
C.O.R.N. Newsletter is a summary of crop observations, related information, and appropriate recommendations for Ohio crop producers and industry. C.O.R.N. Newsletter is produced by the Ohio State University Extension Agronomy Team, state specialists at The Ohio State University and the Ohio Agricultural Research and Development Center (OARDC). C.O.R.N. Newsletter questions are directed to Extension and OARDC state specialists and associates at Ohio State.
Contributors
Disclaimer
The information presented here, along with any trade names used, is supplied with the understanding that no discrimination is intended and no endorsement is made by Ohio State University Extension is implied. Although every attempt is made to produce information that is complete, timely, and accurate, the pesticide user bears responsibility of consulting the pesticide label and adhering to those directions.
CFAES provides research and related educational programs to clientele on a nondiscriminatory basis. For an accessible format of this publication, visit cfaes.osu.edu/accessibility.