C.O.R.N. Newsletter: 2022-07
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Weather Update: Seasonally Chilly Conditions to End March and Start April
Summary
Despite this past weekend’s chill and light snowfall across the state, March is still running 3-5°F above the long-term average (1991-2020). Our active weather pattern continues as well. We have seen the bulk of the precipitation shift a bit northward, with the heaviest precipitation over the last two weeks falling across northwestern counties (Figure 1). A scan of observations shows daily average 2” and 4” soil temperatures running in the low to mid 30s across the north to the low to mid 40s across southern counties, soil moisture running in the 80th percentile and above, and most rivers and streams at or above historical stream flows for this time of year. For the latest up-to-date conditions, seasonal outlooks, and monthly climate summaries, please visit the State Climate Office of Ohio.
Figure 1). Accumulated precipitation for March 15-28, 2022. Figure courtesy of the Midwestern Regional Climate Center (https://mrcc.purdue.edu/).
Figure 2). Precipitation forecast from the Weather Prediction Center for 8pm Monday March 28 – 8pm Monday April 4.
Forecast: Northwesterly flow will keep chilly temperatures and few scattered snow showers in the state for Tuesday. A warm front will push northward Tuesday night and Wednesday. Southerly winds in the 30-mph range will push highs into the 60s and 70s on Wednesday. With low humidity and breezy conditions, there will be an elevated fire danger across the southeast. Showers are likely Wednesday and Thursday as temperatures fall back closer to normal values. Sunshine returns for Friday and Saturday with highs in the 40s and 50s. Another round of showers could move in on Sunday. Overall, the Weather Prediction Center is currently forecasting 0.10-0.50” inch of liquid-equivalent precipitation over the next 7 days (Figure 2), a bit below average for this time of year.
The Climate Prediction Center’s 6–10-day outlook for the period of April 3 – 7, 2022 and the 16-Day Rainfall Outlook from NOAA/NWS/Ohio River Forecast Center indicate that temperatures are leaning below average for the period with near to drier than average conditions as well (Figure 3). Climate averages for this period include a high temperature range of 52-59°F, a low temperature range of 34-38°F, and average weekly liquid-equivalent precipitation of 0.55-1.0 inch.
Figure 3) Climate Prediction Center 6-10 Day Outlook valid for April 3-7, 2022, for left) temperatures and right) precipitation. Colors represent the probability of below, normal, or above normal conditions.
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Winter Wheat Stand Evaluation for 2022
Between planting in the fall and Feekes 4 growth stage (beginning of erect growth) in the spring, winter wheat is vulnerable to environmental stress such as saturated soils and freeze-thaw cycles that cause soil heaving. All of which may lead to substantial stand reduction, and consequently, low grain yield. This year, many areas of Ohio have been wet and wheat plants look poor. However, a stand that looks thin in the spring does not always correspond to low grain yield. Rather than relying on a visual assessment only, we suggest counting the number of wheat stems to help estimate wheat grain yield.
Wheat Stem Count Method: Wheat stems (main stem plus tillers) should be counted at Feekes 5 growth stage (leaf sheaths strongly erect) from one linear foot of row from several areas within a field (Figure 1). In Ohio, Feekes 5 growth stage is generally early to mid-April, depending on the weather and location within the state.
Figure 1. Wheat main stem plus tiller totaling two stems. Measurement tool used to consistently count the number of wheat stems in one linear foot of row.
After counting the number of stems from several areas within the field, calculate the average. Then, use Figure 2 to estimate wheat grain yield. For example, if there was an average of 25 stems in a linear foot of row, median (50th percentile) yield is estimated to be 78 bu/acre with a range in yield of approximately 65 to 85 bu/acre (25th to 75th percentile). Figure 2 was generated using field data from 9 Ohio environments. We will continue to revise this figure as we conduct additional field research projects.
Figure 2. Box-and-whiskers plot showing minimum, 25th percentile, 50th percentile, 75th percentile, and maximum wheat grain yield for a range of stem count measurements from 9 environments in Ohio. Outliers are shown as a dot. Shaded area contains 50% of the yield range (25th to 75th percentile) for each given stem count range.
Limitations: While stand assessment methods can be useful, there are limitations. These yield estimates are made at Feekes 5 growth stage to allow time to plant an alternative crop such as corn or soybean. However, a large portion of the growing season still remains after Feekes 5. Stand assessments may predict high yields, but late-spring freezes, hot/dry conditions at grain fill, or disease may limit yield later in the growing season. Conversely, in some years, stand assessment may predict low yield, but yield could be high if growing conditions are favorable (low disease and long grain fill period).
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Time to Assess Forage Legume Stands
With the onset of recent warm temperatures, forage stands are beginning to green up. Wet soil conditions and widely fluctuating temperatures have presented tough conditions for forage stands this winter. This is especially true of taprooted legumes like alfalfa and red clover. Many forage stands suffered significant fall armyworm feeding damage late last summer and into the fall, so those stands should be carefully evaluated this spring as they greenup. It is time to start walking forage stands (especially in southern and central Ohio) to assess their condition so decisions and adjustments for the 2022 growing season can be planned if necessary.
Forage stand evaluation can be performed when 3 to 4 inches of new shoot growth is present. Select random sites throughout the field and count the plants in a one-foot square area. Check at least 4 to 5 random sites in each 20- to 25-acre area. Random sampling will give the best unbiased overall evaluation of the field.
Plant heaving is always a concern in northeast Ohio and wherever heavy clay soils are present with poor drainage. Crops such as alfalfa and red clover are particularly susceptible to heaving damage. The likelihood of heaving is greater in wet, saturated clay soils with high shrink/swell potential that were exposed to rapid freeze/thaw cycles. Plants can be physically lifted (heaved) out of the soil, exposing the plant crowns to low temperatures and/or physical injury from wheel traffic at harvest time. In severe cases, the plant can be heaved several inches or more out of the soil, breaking the taproot and killing the plant.
While plant counts are useful, crown and root tissue should be evaluated for an indication of how the plant will hold up to stresses in the coming growing season. Dig up 5 to 6 plants in each random field location you sample and split the crowns and roots lengthwise. A healthy plant will have a creamy white color with little to no discoloration in the crown and taproot. These healthy plants will also have numerous shoots that are evenly distributed around the crown of the plant.
Damaged plants often have fewer stems, and those stems often are more numerous on one side of the crown (i.e. shoot growth is not symmetrical). Splitting roots and crowns will reveal darker tissue than the creamy white color of healthy plants. The color tends towards a tan color. There also may be obvious areas of root and crown rot that are dark brown to black in color. Streaks of brown might be seen running down the length of the taproot. Generally, these plants green up in the spring of the year and might appear productive, but because of their compromised root system, they may not survive the entire production year, especially if we have a hot, dry year, or periods of excessive wetness followed by dry spells.
In general, yield potential is significantly reduced if more than 30% of the split roots have brown streaks running down the root and/or black areas of root/crown rot that cover greater than 30 to 50% of the root diameter. The grower may want to consider alternative forage options such as terminating the stand after a first cutting and planting to silage corn or possibly to a warm season annual forage crop such as sudangrass or sorghum x sudangrass (BMR varieties are preferred for dairy cattle). Interseeding with other forage species may also be considered to thicken the stand, just don’t try to interseed alfalfa seed into an existing alfalfa stand because of autotoxicity.
If the alfalfa stand looks tough, it might be a blessing in disguise. Yield declines as the stand ages, especially in years 4 and 5 of an alfalfa stand. Consider also that a terminated forage legume stand can supply all the nitrogen needs for first year corn (or sorghum grasses) and will even supply a significant amount of N to second-year corn after alfalfa is terminated. This too should be considered when deciding whether to keep an old forage legume stand that might not be so productive this year, especially considering the current high price of fertilizers. Perhaps the old alfalfa stand will serve you better as a N supplier and yield booster for your corn (corn after alfalfa usually yields more than corn after soybeans), with the opportunity to perhaps plant a new alfalfa stand where you would have planted the corn.
Numerous studies have demonstrated that alfalfa N credits can supply all the nitrogen needs of first year corn, including first year no-till corn following alfalfa. If it makes you sleep better, apply a little starter or sidedress N (30 lbs/acre or less) to “prime the pump” in anticipation of the organic nitrogen release from the forage legume stand. But most studies show no response to any fertilizer N on first year corn after alfalfa. In addition, second year corn after alfalfa also has a substantial N-credit from the alfalfa! What’s more, corn will yield more following alfalfa than soybeans. Yes, your grandfather was smarter than you might think with that corn – alfalfa (or red clover) rotation he always used! There are many more benefits to that rotation than I have space to outline in this article.
For more details on winter injury evaluation in forages, please refer to the Corn, Soybean, Wheat, and Forages Field Guide, available at https://extensionpubs.osu.edu/corn-soybean-wheat-and-forages-field-guide/.
Although winter temperatures, snow cover, and soil wetness are primary driving factors affecting tall forage legume winter survival, there are several management factors that can affect the degree of winter injury suffered by forage stands. Those factors include:
- Variety selection: varieties with good winter hardiness and disease resistance generally survive longer.
- Soil fertility: adequate soil potassium is associated with enhanced tolerance to winter injury.
- Soil drainage: tiling and improving drainage helps prevent ice-sheeting and heaving and slows development of crown and root diseases.
- Harvest management: frequent cutting is associated with a higher risk of winter injury, particularly if the last fall cut was made in late September to mid-October.
As you walk your forage stands, be sure to check for the presence of winter annual weeds! You will want to act early this spring if winter annuals are abundant (see accompanying article in this issue about winter annual weeds).
I have not written much here about assessing grass stands, but grass hay and pasture stands should also be walked early to assess their spring vigor and growth as the stands green up. This is especially true where armyworm feeding was severe last fall.
Taking the time to do a stand evaluation and further assess forage plant health and the extent of winter injury will allow the grower to have a better idea of the yield potential of the stand. This will help inform whether the stand can continue another year or would be better suited as a rotational crop this year.
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Extension and Ag Researchers Work Toward Agroecosystem Resilience
Introduction: The eastern Corn Belt Region (ECBR) of the United States (Figure 1) has experienced increasing temperatures with more extreme precipitation events in recent decades. Current climate projections show these trends will likely continue and intensify in the future. As a result, land use and management adaptations impacted by the agricultural, policy, and technological sectors will be needed to meet food production challenges and secure the economy. Thus, stakeholders at household, firm, industry, community, and regional levels need more information and a better understanding of the system-wide implications of these changes.
Figure 1: Eastern Corn Belt Region of the U.S. and key River Basins evaluated in the study.
Researchers and extension professionals at The Ohio State University are working together to unwrap some of the complexity involved in this grand challenge through a project linking expected local climate change, farmer decisions, and ecosystem, economic, and policy outcomes. Since the ECBR agroecosystem is managed with agricultural production, conservation, and societal well-being goals in mind, a linked set of climate systems, regional economy, and agroecological models are used to evaluate policy and program impacts. Using results from one model to inform input into another model provides a means to project decision impacts on the sustainability and resilience of this region under varying future scenarios. Here we summarize the main findings to date. For larger versions of the figures below, videos explaining the project components in more detail, and our stakeholder engagement process, please visit Agroecosystem Resilience Project.
Climate Future: Figure 2 summarizes the mean changes in temperature and precipitation throughout the remainder of this century given different climate scenarios (low or high degree of change – think range or possible change). In both scenarios, temperatures rise, the growing season lengthens, and precipitation increases and becomes more intense across the ECBR, though there are regional differences. These changes impact farmer decisions such as when to plant and harvest, what crops and varieties to grow, and nutrient application timing decisions. The climate scenarios identified increase crop stress, accelerate plant growth, and increase potential weed, insect, and disease pressure. It will also likely affect the size of equipment farmers will use, whether to take advantage of the longer growing seasons with double cropping, and potentially lead to more erosion and nutrient loss in the absence of mitigation.
[Click here or on the infographic for a larger version]
Figure 2: Infographic showing change in climate across the Eastern Corn Belt Region of the U.S. Current ranges are indicated in blue with a Low (yellow) and High (red) range of change indicated for key temperature and precipitation variables.
Farmer Decisions: Farmers across the region were presented with a range of climate scenarios in a mail survey. The questions asked how they intended to adapt to climate variability and what differences among farmers cause changes in intended adaptations. Figure 3 shows a second infographic based on these results and the following are the key takeaways from the 918 viable surveys returned:
- Most farmers (51%) believe that the climate is changing but mostly due to natural changes, while 42% believe there is a lot of disagreement among scientists about whether the climate is changing.
- While respondents have experienced climate impacts (e.g., warmer winters, variable planting dates, variable rainfall), the experience of these impacts is still varied across the farming population and only of slight concern to most farmers.
- Most farmers (55%) report planting more resilient varieties of crops already grown as a form of adaptation. Approximately one-quarter report other past adaptations such as outsourcing activities, seeking off-farm employment and installing more drainage tile.
- Future adaptations of greatest interest include continuing to plant more resilient varieties of crops that they already grow, continuing to outsource some activities on the farm (e.g., fertilizer application, etc.), and changing tillage practices (e.g., adopting no-till or conservation tillage).
- In terms of explaining future adaptation, a consistent trend is that adaptation is more likely on larger farms. Farmer characteristics (e.g., climate concern, prior experience with climate impacts) help explain whether someone is likely to engage in some adaptation, but such characteristics were not as useful at understanding specific adaptations (beyond land retirement).
- Finally, the expected future changes in climate and shifts in conservation payments helped explain what specific adaptations were selected (e.g., drainage tile more likely to increase when the future is characterized by later planting dates and more rainfall).
[Click here or on the infographic below for a larger version.]
Figure 3: Infographic showing the Main Adapter Types (yellow -middle), Main Decisions facing farmers (red – left), and the Top Adaptation Practices (blue -right) given expected climate future. Farmer thoughts on climate change are provided in the inset at the bottom of the graphic.
Regional Model, Ecosystems Services, Optimal Policies: Work on the integration of all these components into a regional agroecosystem model continues. Our current work focuses on establishing models to address policies by state and local governments that augment federal policy requirements and incentives and/or address issues that have not been addressed in federal policy. We have conceptualized, and are preparing to simulate, a carbon-trading scheme that, combined with aggressive carbon sequestration efforts, can reduce the costs of reducing net carbon emissions in the region. These efforts have been guided by suggestions from our Stakeholder Advisory Group, made up of local and regional commodity, agribusiness, and policy experts.
Extension and Engagement: We continue to disseminate climate related results to diverse stakeholders including those attending Ag meetings, private consulting and insurance firms, Farm Science Review, and through the North Central Climate Collaborative. In addition to the infographics above, we have created a series of educational videos with a second round focusing on ecosystem services and the policy assessment being developed. Participants have reported increases in their knowledge of climate and agriculture, including awareness of changes that are happening, challenges farmers will face, and ways they can reduce negative impacts on their farming operations. We encourage everyone to check back with us at Agroecosystem Resilience Project as we complete this project in the coming year.
Project Leads
Robyn Wilson – Project Leader, School of Environment and Natural Resources/School of Communication, Farmer behavioral modeling, wilson.1376@osu.edu
Gregory LaBarge – OSU Extension, Stakeholder Advisory Team coordination & farmer/stakeholder engagement, labarge.1@osu.edu
Aaron Wilson – Byrd Center/OSU Extension/State Climate Office of Ohio, Climate projections and Education Outreach, wilson.1010@osu.edu
Yongyang Cai – Department of Agricultural, Environmental, and Development Economics (AEDE)/Sustainability Institute, Integrated model developer and economist, cai.619@osu.edu
Elena Irwin – Department of Agricultural, Environmental, and Development Economics
(AEDE)/Sustainability Institute, Multi-sector regional economic and land use modeling, irwin.78@osu.edu
Kaiguang Zhao – School of Environment and Natural Resources, Model change in ecosystem services, zhao.1423@osu.edu
Alan Randall – Department of Agricultural, Environmental, and Development Economics (AEDE), Design
of regional model and interpretation of results, randall.3@osu.edu
Jason Cervenec - Byrd Center/State Climate Office of Ohio, Farmer/stakeholder engagement, cervenec.1@osu.edu
Kristi Lekies – School of Environment and Natural Resources, Evaluator, lekies.1@osu.edu
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Alfalfa Weevil - A Check in Time Saves Cryin'
Even though it feels like January, we’re almost to April, and in April you should begin scouting alfalfa for alfalfa weevil. Overwintered adults begin laying eggs when temperatures exceed 48°F. Peak larval activity and feeding damage occur between 325 and 575 heat units (based on accumulation of heat units from January 1 with a base of 48°F). Current (Jan. 1 – March 26) heating units range from a high of 195 in southern Ohio and a low of 67 in northeast Ohio, and the current cold snap will slow things down a bit. But we have warmer temperatures in forecast for midweek; handful of warm days can jump start things fast.
Accumulated growing degree days (base 48°F sine calculation method) for January 1-March 26, 2022 at several CFAES Ag Weather System (https://www.oardc.ohio-state.edu/weather1/) locations and additional NOAA stations around Ohio (Midwestern Regional Climate Center (https://mrcc.purdue.edu).
In short, start preparing soon to begin scouting, especially in fields that were damaged last fall by the fall armyworm, because we don’t want to add more insult to those fields early this season. Alfalfa fields should be scouted weekly for weevils until at least the first harvest. Don’t let your guard down with snaps of cooler weather! We’ve seen significant weevil infestations in past years when early warm weather pushed weevil development earlier than normal, followed by cooler weather later that slowed alfalfa growth. The result was weevil larvae reaching stages when a lot of feeding occurs and the slowed alfalfa growth not staying ahead of their feeding damage. Follow-up scouting may be needed after the first harvest in heavily infested fields.
Spot problem fields early by checking alfalfa tips for feeding damage – small holes and a tattered appearance. Fields that have a south facing slope tend to warm up sooner and need to be checked for weevil earlier.
Here is a video about scouting weevils in alfalfa: https://forages.osu.edu/video
Scout for alfalfa weevils by collecting a series of 10 stem samples from various locations. Place the stems tip down in a bucket. After you’ve collected 10 stems, shake the stems vigorously into the bucket and count the larvae. Divide this number by 10 to get the average number of larvae per stem. Do this procedure at least 3 times (for a grand total of 30 stems, in 10-stem units). Alfalfa weevil larvae go through four growth stages (called instars). The shaking will dislodge the late 3rd and 4th instar larvae which cause most of the foliar injury. Close inspection of the stem tips may be needed to detect the early 1st and 2nd instar larvae. Also record the overall height of the alfalfa. The treatment threshold is based on the number of larvae per stem, the size of the larvae and the height of the alfalfa according to the following table. When alfalfa is around 12-16 inches in height, growers can consider an early harvest rather than spraying, if they feel the current growth is sufficient to justify the cost of harvest or if spraying can’t be done for some reason (e.g., organic production). When alfalfa stem height is over 16 inches, we would always recommend an early cutting. In those fields which are cut early for alfalfa weevil, the regrowth should be checked closely to make sure weevils that are still alive do not prevent good regrowth.
Table 1. Action thresholds relevant to stand height, tip feeding, and density of larvae per stem.
Stand Height Inches
Indication of Problem % Tip Feeding
Problem Confirmation Larvae per Stem
Recommended Action
6
25
1
Recheck in 7 days
9
50
> 1
Spray
12
75
> 2
Spray
16
100
> 4
Harvest early
When harvested early due to weevil, check within one week for regrowth.
For more information about alfalfa weevil, visit our factsheet at https://ohioline.osu.edu/factsheet/ENT-32 If you are interested in a more detailed treatment of how growing degree days can be used in management decisions for alfalfa weevil, visit this website from the University of Kentucky https://entomology.ca.uky.edu/ef127
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Wheat Herbicides, Cressleaf Groundsel, Enlist - Weed Management Odds and Ends
Based on the current price of wheat, some wheat fields with less than ideal stands are being taken to yield instead of terminated. A uniform wheat stand usually provides most of the weed control that’s needed. Weeds will likely be more evident and in need of control where stands are thin or erratic. We have been told wheat herbicides are scarce, so growers might want to check with suppliers soon. Reminder that any product containing dicamba has to be applied prior to jointing. Link to wheat herbicide effectiveness table and growth stage chart.
Reminder about the potential for spring infestations of cressleaf groundsel in wheat, forages, and hayfields. This weed, poisonous to livestock, is a winter annual that emerges in the fall and flowers in the spring. It’s most likely to occur in new stands that are seeded the previous summer/fall. Growers are often not aware of this weed’s presence until it does flower, at which point the only course of action is to destroy the first cutting of hay to avoid risk of poisoning. Fields should ideally be scouted and treated in the fall when groundsel is easier to control. Where that didn’t occur, scout now and treat when it’s still small. More information on cressleaf groundsel can be found in a previous C.O.R.N. article, fact sheet, video, and slides.
Update on the mesotrione article in last issue. The mestrione products that are labeled for use on “mesotrione-tolerant” or “mesotrione-resistant” soybean varieties can apparently legally be applied to any GT27 soybean (since every GT27 soybean carries this resistance). We stated in the article that the seed tag had to also indicate the variety was “mesotrione-resistant or tolerant”, but we were subsequently provided new information by ODA. This label is for preemergence use only, not postemergence.
There seems to be some optimism that USEPA will fairly soon approve an amended label for Enlist products that “fixes” the prohibition in 12 Ohio counties. The amended label was submitted by Corteva a while back. No one can say for certain when approval will come because – well – it’s the EPA. Note to anyone in EPA that might be listening – having bungled the whole dicamba thing for four straight years, maybe you could throw us a bone and demonstrate some expediency on this issue.
Go here to order the “2022 Weed Control Guide for Ohio, Indiana, and Illinois”.
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Did you miss Conservation Tillage Conference? It’s not too late!
Exclusive access to the recordings of presentations at CTC2022 is now available, until April 25. If you missed CTC, you can watch ALL concurrent sessions and Steve Groff’s keynote speech, plus short messages from our exhibitors and major sponsors. This package includes continuing education credits for Certified Crop Consultants via a QR code is included with each presentation.
Register today, or any day until about April 20, to access the CTC presentations for only $100.
The full program, including CCA credits, can be viewed on the website: https://ctc.osu.edu. (On the home page, click on the RED box)
After registering, you will receive an email with a link to the presentations. Presentations are grouped by concurrent session, as they are listed in the program.
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Soil Health Workshop Series in Kenton
A series of Soil Health Workshops will be held on April 4th (Beginner) and April 6th (Advanced) at the Hardin County OSU Extension Office in Kenton. Jim Hoorman will be the main presenter. Hoorman has worked for OSU Extension for several years as a county extension educator in Putnam County and USDA Natural Resources Conservation Service (NRCS) in the Soil Health Division for Ohio and Michigan.
The first workshop will be April 4th from 9:00 am - 4:00 pm, with topics ranging from soil ecology and nutrient recycling, dealing with soil compaction, and putting an economic value on soil health will be discussed in the morning. In the afternoon, topics on keeping nutrients in the soil and getting started with cover crops: clovers, legumes, grasses, and brassicas will be discussed.
The second day, April 6th from 9:00 am - 4:00 pm, topics will include setting up a no-till planter, adjusting to adverse weather, making no-till corn succeed, and learning more about beneficial microbes. Afternoon topics include fertilizing for higher yields with micronutrients, using humic compounds to enhance fertilizer and plant growth, and dealing with pests (weeds, insects, and diseases).
Participation is limited to 25 attendees for each workshop. Sign up by calling the Hardin County OSU Extension Office at 419-674-2297. The cost of each workshop will be $25 per day which includes lunch and materials. Registration is requested by April 1. Participants can enroll in either or both days
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 more information, visit cfaesdiversity.osu.edu. For an accessible format of this publication, visit cfaes.osu.edu/accessibility.