C.O.R.N. Newsletter: 2022-29
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Autumn Harvest Still Looks Warmer Than Normal
The September to November timeframe still looks warmer than normal, somewhat like last year but not as warm in September into October as last year with a medium to high confidence in the outlook. Rainfall looks generally close to normal through November. Confidence in the rainfall is not as high and is considered medium as there is some uncertainty in the preferred tropical moisture flow. Like last year the first freeze looks to be normal to later than normal in October.
For September, the first half looks slightly warmer and drier than normal (see latest rainfall outlook in attached image). Uncertainty grows in the second half of September as it might turn wetter than normal. The second half will completely depend on tropical moisture return from the south. Therefore, a near normal rainfall pattern is currently anticipated when you average out the two September periods.
For October and November above normal temperatures will persist with precipitation somewhat variable around normal with a slight lean toward drier than normal.
It does not appear we will see any early freeze this autumn which is good news. Expect the first freeze about on time to a week or two later than normal in October.
The latest climate outlooks can be found by NOAA at: https://www.cpc.ncep.noaa.gov
Finally, for the first half of September rainfall is forecast to average 1-2 inches which is not far from average.
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Late-Season Soybeans Can Be Pest Magnets
At the end of the growing season, when many soybean fields are shutting down, those which are still green can be a magnet for certain insect pests as they leave the mature fields. Double-crop soybeans and late planted beans that are running behind and are still fresh can be attractive for stink bugs, bean leaf beetles, and sometimes grasshoppers when they leave yellowing fields for greener pastures. If you have such soybean fields in areas where other fields are maturing, they are worth an extra eye until they reach the R6 (full seed) growth stage. After R6, the yield is mostly set and insecticide will not provide a return. Also, if you do spray late in the season, be mindful of the pre-harvest interval of the product you’re using, which can be up to several weeks. Consult our pest management guide for more information about these chemicals:
https://aginsects.osu.edu/news/msu-osu-insect-ipm-guideFor defoliating insects like grasshoppers, look for defoliation levels across the entire field of around 15% and whether the insects are still present. A guide to defoliation can be found here: https://aginsects.osu.edu/sites/aginsects/files/imce/Soybean%20defoliation%20Final.pdf
For stink bugs, which poke directly into the seed with their straw-like mouthparts, take several sweep net samples of 10 sweeps each in different parts of the field. If you average 4 stink bugs per 10-sweep set (grain) or 2 bugs per set (food-grade and seed) consider treatment. https://aginsects.osu.edu/sites/aginsects/files/imce/Stink%20bug%20ID%20card%20ID%205_1_19.pdf
Bean leaf beetles pose little threat when feeding on foliage earlier in the season. Later in the season they may feed directly on the pods, which can cause more damage – either through direct damage to the seed, or through opening the pod to disease. Inspect all the pods on 10 randomly selected plants and count the total number of pods and the number showing pod injury. Use your totals to determine percent pod injury. Treatment is justified if the percent pod injury is reaching 10 to 15%, and bean leaf beetle adults are still present and active.
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Dicamba Label Clarifications
We have received questions about the use of dicamba after June 30, for control of weeds in wheat stubble and other situations. The June 30 cutoff applies only to use of XtendiMax, Engenia, and Tavium in Xtend and XtendiFlex soybeans, which is the only labeled use for these products. Current uses of other dicamba products are not affected by the June 30 cutoff, including fallow, pasture, small grain, etc, as long as label directions are followed. We would of course encourage caution and common sense with regard to use of dicamba in hot weather, and near sensitive plants.
Another subject – it’s not too late to scout fields for escaped water hemp plants and remove them prior to mature seed production. We have been able to find mature seed but much of it is still immature. For a primer on determining the presence of mature seed, check out this short video.
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Lep Monitoring Update: FAW Trapping Continues – Numbers Low in Ohio
Fall Armyworm
Additional counties set up Fall armyworm (FAW) traps over the past week, resulting in a total of 18 counties monitoring across the state. The majority of counties reported low numbers of FAW (an average of 7 or less moths per week), except Lucas, Putnam and Wood counties (Figure 1). The overall statewide average was up slightly with 3.9 moths per trap (3.4 last week). We will continue monitoring and reporting FAW numbers in Ohio over the next 4 weeks.
Fall Armyworm Moth Map
August 22 - 28, 2022
Figure 1. Average fall armyworm (FAW) moths captured from August 22nd through August 28th. 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.
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Incomplete Kernel Set and Tipped-Back Corn: How Do They Differ?
Crop tours in Ohio have indicated that crop pollination was generally good, but kernel abortion was noted in some fields. It is important to recognize that both affect final corn yields. Similarly, it is relevant to understand when/how issues occur (e.g., pollination issues vs. kernel abortion). The result is the same: fewer viable kernels per ear, but diagnosing the difference helps understand and identify the potential associated causes.
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Incomplete kernel set
Poor or scattered kernel set in the ear (Fig. 1). Poor or scattered kernel set on ears results from either failed pollination/fertilization of ovules (VT or R1) or abortion of young kernels during the several weeks after pollination (R1–R3).
Figure 1. Ears displaying incomplete kernel set at varying degrees from least (left) to most (right).Possible causal factors: Silks damage (e.g., insect feeding and silk clipping), stress due to drought and high temperatures, pollination issues (e.g., asynchronous pollen shed and silking, inadequate pollen supply), phosphorus deficiency, herbicide injury, and cloudy days (due to low photosynthetic capacity).
Postulated development timing: Pollination, VT or R1; and early reproductive stages, R1–R3.
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Tipped-back ears
Missing kernels at the tip of the ear (Fig. 2). Tipped-back ears can include failed pollination or kernel abortion at the ear tip and progressing down to varying severities. Tip-back ears are also referred to as tip-dieback, nosing, or tipping back. The nose or tip back in a corn ear can be the result of different conditions—a plant population response (i.e., higher seeding rates, more interplant competition, failure of pollination of ovules in the ear tip) and weather after pollination (i.e., non-favorable conditions, inadequate photosynthate supply, kernel abortion). Unfertilized ovules and aborted kernels may appear dried up and shrunken, but aborted kernels often have a slight reddish or yellowish color. In a corn ear, pollination/fertilization starts from the base and ends on the ear tip. Hence, kernels that develop on the tip of the ear are particularly vulnerable or susceptible to abortion as they form last (if they form at all).
Figure 2. Tip back ear in corn displaying lack of pollination in the very tip (whiteish color) and kernel abortion during grain filling period below the tip (reddish or yellowish color).Possible causal factors: Pollen and silk availability, kernel abortion, heat/drought stress, genetics, higher seeding rates, nitrogen deficiency, foliar diseases, and cloudy days.
Postulated development timing: Pollination, VT or R1; and early reproductive stages, R1–R3.
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Management Considerations
Follow recommended guidelines for minimizing crop stress for incomplete kernel set (Fig. 1) and tipped-back ears (Fig.2). This includes (but is not limited to) maintaining appropriate fertility, adjusting planting depth with varying soil conditions, following recommended herbicide application dates/rates, selecting adapted hybrids and seeding rates consistent for yield potential and planting dates, avoiding planting too early in wet/cold soils, and minimizing weed competition with effective herbicide applications and/or timely cultivation.
Ears exhibiting tip back may not always be cause for concern. Favorable growing conditions may result in more potential kernels per row than usual. So even if corn ear tips are not filled entirely due to poor pollination or kernel abortion, yield potential may not be affected significantly, if at all, because the number of kernels per row may still be above normal. On the other end, a general rule of thumb can be that presence of ears consistently filled to the very tip may indicate that a higher plant population might have been needed to optimize corn yields.
Resources
Ortez, O. A., McMechan, A. J., Hoegemeyer, T., Ciampitti, I. A., Nielsen, R., Thomison, P. R., & Elmore, R. W. (2022). Abnormal ear development in corn: A review. Agronomy Journal, 114, 1168– 1183. https://doi.org/10.1002/agj2.20986.
Incomplete Kernel Set – Whole Ear: https://u.osu.edu/mastercorn/incomplete-kernel-set/.
Tip Dieback (also referred to as “tip-back”, or “nosing or tipping back”): https://u.osu.edu/mastercorn/tip-dieback/.
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Can We Get More Information From Our Soil Samples?
A soil test is a profitable investment to inform our nutrient management strategy. Some farms find value in increasing sampling frequency (every one to two years) and intensity with more samples per field (0.5 versus 2.5-acre grid). Another possible way to increase the value of soil sampling is to consider additional tests that can provide helpful management information. Some examples are soil health, soybean cyst nematode, and corn nematode testing.
Depending on the lab we use, some tests may be available by checking a box on the lab input form. Sample collection costs may be minimal if we need a separate sample for a specific analysis. For example, depending on how we collect the nutrient soil sample, we often collect more soil than what will fit in the lab bag. Rather than tossing the excess soil back in the field, we can put it in a second bag. If the soil volume is not enough to split for a second (or third) analysis, we can collect additional cores.
There is a wide range of available soil health measures. The Soil Health Institute did a broad ranging analysis of 30 soil health test. SHI recommends a minimal suite of three measurements to be widely applied across North America (and likely beyond). Those measurements include: 1) soil organic carbon concentration, 2) carbon mineralization potential, and 3) aggregate stability.
We have recently updated our guidelines for choosing a soil nutrient lab to include information on nutrient testing and soil health measures. Common nutrient and soil health terms are described. Plus, a listing of labs and services they offer is shown. Find the fact sheet at https://ohioline.osu.edu/factsheet/anr-0107 The list here focuses on a few of the more common tests available from labs in our region.
- Active organic matter (POXC). Measures the portion of organic matter most likely to interact with plants and fertility.
- Solvita test. This soil respiration test measures the soil's biological activity.
- Haney test. This test measures how hospitable soil is for microbial life. Tests include measuring soil nutrients available to soil microbes, soil respiration (microbial breathing), water-soluble organic carbon, organic nitrogen, C:N ratios, and NO3, NH4, and other key nutrients. The results indicate the amount of food readily available to soil microbes and is sensitive to measuring root exudates and decomposed organic material.
- Bulk density and aggregate stability. These laboratory tests measure soil structure and compaction.
- Soil texture (or particle size analysis). A measurement of the amount of sand, silt, and clay in your soil, which dictates soil type.
Soybean cyst nematode (SCN) testing
Active management of Soybean Cyst Nematode (SCN) begins by knowing if you have the problem. Until the end of September (beginning of October for late planted soybean fields) you can scout fields and carefully dig out root to check for the presence of SCN. In addition, a composite soil sample will reveal the presence (or not) of SCN in your field, but most importantly, it will tell you the levels of SCN (Know your numbers!), which will help you select the best SCN management approach. You can collect soil sample for SCN test any time (i.e., in fall after harvest, spring before planting, or during the growing season).
As we mentioned above, the same composite sample collected for soil analysis can be divided into a subsample for SCN testing. Remember that nematodes are alive, and we want them alive until samples are processed. Therefore, samples must be protected from heat and direct exposure to sunlight until they are shipped to the lab. Find details about how to sample and where to send your SCN samples here.
Furthermore, with funding from Ohio Soybean Council and The SCN Coalition, growers may submit up to two soil samples to the Soybean Pathology and Nematology Lab, and we will test them for SCN free of charge.
Corn nematode testing
Several nematode species can negatively impact corn production (Fig. 1).
Sampling for corn nematodes is slightly different than sampling for SCN. For example, we do not recommend collecting samples for corn nematode analysis in the fall. We must sample during the growing season to determine the relationship between nematode levels and potential damage to corn. Only corn fields showing symptoms [chlorotic and stunted plants, swollen and poorly developed roots (Fig. 2), etc.], specially under nutrient availability, should be sampled for corn nematodes.
Samples can be collected when symptoms start appearing during the season. Up to corn growth stage V6, soil and root samples must be collected for corn nematode analysis. Collect a composite soil sample from the transition zone, the area between symptomatic/damaged plants and healthy ones. Using a shovel, collect plants with their roots from the transition zone. Place these roots in well-labeled plastic bags for shipping. Between corn growth stages V6 to R3, only composite soil samples should be collected. For corn growth stage R4 and beyond, we do not recommend sampling because the nematode levels are variable and not consistent with potential damage to corn. Keep in mind that nematode samples are alive, therefore, you must handle it carefully. To keep the nematodes alive, store your samples in a cool, dark place out of direct exposure to sunlight and ship them to the lab as quickly as possible.
Final considerations
Yield or past soil test results should drive sample area size decisions. A single sample should not represent more than 25 acres. Grid or zone sampling often results in zone sizes of two to twelve acres and target lime or nutrients to areas of greatest need. Sample depth should be consistent. For sample depth, our Tri-State Recommendations use an 8-inch sample core. Mark your probe at your selected depth. Throw out and take another sample core when cores are compacted in the probe. We like to blame the lab for bad samples, but we generally see more variability in the sample collection process than laboratory procedures for nutrient analysis. If you want more information on soil sample collection procedures, see the factsheet at https://go.osu.edu/soilsample .
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What Is a Good Soil Health Number In Ohio?
As our understanding of soil health advances, farmers are increasingly interested in assessing and improving soils on their farms. Several commercial labs now offer soil health analyses but generating values in a lab is only the first step. A frame of reference for what constitutes a typical, low, or high soil health value is essential for understanding these tests and inferring soil function. A common question farmers ask is, “What’s a good soil health number?”
A recent report helps answer this question, by providing a state-wide baseline of soil health values from Ohio. This report can now help farmers and landowners assess soil health in their fields. The full report can be found here: go.osu.edu/SH-baseline with a summary provided below.
The assessment was compiled from 10 distinct projects conducted by Ohio State University from 2015 – 2021. These projects involved mostly on-farm research that either included a simple agronomic manipulation or sampled soil in a survey approach. Nearly all soils were from production agricultural fields. Projects were diverse and included field crop fertilizer recommendation trials, certified organic corn fields, soybean fields, hopyards, and tomato fields. A total of 2,454 soil samples came from 75 counties across Ohio (Figure 1). Soils were most commonly a single soil sample per field, but no more than 10 soil samples per field.
Figure 1. The Ohio counties (red shaded) where soil samples were collected from for this baseline soil health assessment.
Soils were sampled typically in the fall or spring and mailed or transported to Ohio State where they were dried and ground to <2 mm. Soil health analyses (POXC or active carbon, Respiration, and Soil Protein) were run in the Soil Fertility Lab (soilfertility.osu.edu/protocols), and routine nutrient analysis (pH, Mehlich-3 nutrients, organic matter via loss-on-ignition) was run by Spectrum Analytic with recommended procedures (NCERA-13, 2015).
As expected, soil properties varied greatly across all 2,442 soil samples (Table 1). Fifty percent of the soils had optimal pH values 6.0 – 6.8 and most had sufficient Mehilch-3 P and K values. In general, soil test levels were in optimal ranges for grain crops in Ohio (Culman et al., 2020). Soil organic matter ranged from 0.1 to 9.8% for these soils, with 50% of the values falling below and 50% of the values falling above 2.2% (median value). Soil health measures that reflect biologically active organic matter values varied greatly, with median values of 496 mg/kg for POXC, 46.5 mg/kg for respiration and 4.4 g/kg for soil protein (Table 1).
Table 1. Summary of soil data based on percentiles (n=2442).
Variable
Minimum
25th
50th
75th
Maximum
pH
4.2
6.0
6.4
6.8
8.0
Mehlich-3 Phosphorus (mg/kg)
2
27
44
70
969
Mehlich-3 Potassium (mg/kg)
28
105
140
179
633
Cation Exchange Capacity (meq/100g)
1.9
9.1
12.0
15.3
27.5
Organic Matter (%)
0.1
1.7
2.2
2.7
9.8
Soil Organic Carbon (g/kg)
0.6
1.4
1.7
2.1
7.1
Permanganate Oxidizable Carbon (mg/kg)
55
401
496
617
1433
Respiration (mg/kg)
4.4
32.0
46.5
65.3
458.5
Soil Protein (g/kg)
1.5
3.9
4.4
5.3
25.6
The Importance of Soil Type
Soil type often needs to be considered when assessing soil fertility test values. For example, sandy soils cannot hold as much Mehlich-3 K as a clay soil. Similarly, there is widespread agreement that soil type needs to be considered when evaluating soil health organic matter values. Soils with more clay are inherently capable of holding more organic matter relative to sandier soils. Because of this, we grouped soils by soil type and by CEC (cation exchange capacity).
The tables in the report are intended to provide some reference for typical soil health values based on a given soil type. When a grower gets soil health test results, they can use these tables to see where their soils fall relative to other fields in Ohio. This is an important first step in establishing baseline values. The next step is using this information to understand how management impacts soil health, and ultimately how these values can inform future management and actionable decisions.
More information is provided in the full report: go.osu.edu/SH-baseline
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Survey of Landowner Experiences with Natural Gas Pipeline Installations
Numerous natural gas pipelines have been installed in Ohio to transport fracked petroleum from Eastern Ohio to other regions of the state. These pipelines are essential components of Ohio’s energy infrastructure and bring economic growth to the region. However, the pipeline installation process creates a large amount of disturbance that can have lasting impacts on soil and crops.
We recently conducted a landowner survey intended to capture the collective experiences of Ohio residents having pipelines installed on their land. We targeted landowners with property crossed by one of three independently operated pipelines in Ohio that were installed from 2016-2018: the Rover, Utopia and Nexus pipelines. We sent out 600 surveys to a random sample of landowners and had a 31.5% response rate with responses from 22 Ohio counties.
The link to the fully report can be found below, but highlights of our findings include:
- Pipeline installation often occurred when soil was too wet to work.
- 71.5% of respondents answered “Yes” to the question, “During the installation process, were there times when soil conditions were not optimal, but pipeline installation continued?”
- Those who answered “Yes” were asked to rate how sub-optimal the conditions were during installation. 55.7% said the soil conditions were extremely sub-optimal (soil completely saturated).
- Soils were often not remediated to their original condition after pipeline installation
- Three years after site remediation was complete, only 17.6% answered “Yes” to the question, “Do you feel that your land is generally back to the condition it was prior to pipeline installation?” By contrast, 82.4% of the respondents answered “No” to this question.
- Respondents were asked to report yields they had measured in areas over the pipeline relative to an adjacent, unaffected area. We received 52 paired yield measurements in corn, popcorn, soybean and wheat. All but one response indicated yield reductions over the pipeline right of way compared to an adjacent area (Figure 1). Yield reductions across crops ranged from 22% more yield to 100% less yield (total crop failure), with average declines across crops approximately 40 – 60%.
Figure 1. Farmer-reported percent differences in crop yields between the pipeline and an adjacent, non-impacted area. Values on the left side of the red dotted line indicate a yield reduction over the pipeline when compared with adjacent areas, while values on the right side indicate an increase in yield.
- Landowners had mixed, but often negative experiences with the installation process
- Roughly half of the respondents (56.3%) were not satisfied with the experience compared to satisfied (31.9%)
- About one-third of respondents (36.1%) felt that they were fairly compensated for the easement, while 46.6% did not feel fairly compensated.
- A quarter (26.7%) would be open to negotiating a future easement compared with 55.6% who said they would not be open to another pipeline easement.
- Responses were mostly consistent across the three targeted pipelines
- Responses to questions were similar across pipelines, indicating these experiences might be considered typical with contemporary pipeline installation methods.
- Overall, survey responses are consistent with results of fieldwork conducted by our team on 29 farms across 8 Ohio counties in 2020 and 2021 that documented significant soil degradation and reduced crop yields within pipeline easements compared to nearby soils.
More pipelines are projected to be installed in Ohio in the coming years. But farmers should be appropriately compensated for soil degradation and sustained crop yield losses from these activities. Current easement payments and mitigation requirements should likely be revisited, as all available evidence from Ohio suggests that degradation often persists for more than 3 or 4 years after installation and remediation is complete.
The full report to this survey can be found here: go.osu.edu/pipeline-survey
More information on the pipeline project can be found here: go.osu.edu/pipeline-study
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.