C.O.R.N. Newsletter: 2023-19
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What happened with crop yields during 1988 and 2012? A recap
After a couple of weeks of dry conditions in the state, “the skies opened up” during the last week or so (Figure 1). Showers and storms moved across the state during this period. Prior to these rainfall events, we heard comments “This is starting to look like 1988”, but thankfully, we think that we did not get there. The recent rains and cooler temperatures have alleviated (at least to some degree) the drought concerns in areas of the state. We still need steady rains throughout the growing season, and we hope we get them. For now, the next 7-day forecast has rains for most regions. Despite the recent rains and showers in most of the state, USDA-NASS reported (06/12/23) topsoil moisture conditions rated as 35% very short, 42% short, and 23% adequate. Subsoil moisture was rated 17% very short, 53% short, and 30% adequate. We anticipate these numbers will change after the rainfall last week. The soil surface conditions were the most affected during the dry period. At deeper layers in the soil, better moisture conditions have been available.
As a recap… 1988 and 2012 were years with significant drought effects across the region, here is a summary of drought impact for Ohio during those two years. We present the percentage yield reduction compared to the average yield in three years prior to drought conditions. This summary is presented using the USDA-NASS data, and split by Ohio Crop Reporting Districts, CRDs (Figure 2).
1988: Crop Yield Response to Drought for Ohio by State Total and Crop Reporting District (CRD). Percentage reduction of 1988 yields compared to the average of the three previous years (1985-1987). Data from USDA-NASS.
Crop changes – 1988
Crop Reporting District
Corn
Corn Silage
Soybean
Wheat
10 – Northwest region
-32%
-31%
-38%
-18%
20 – Northcentral region
-38%
-33%
-40%
-12%
30 – Northeast region
-39%
-39%
-17%
4%
40 – West central region
-35%
-35%
-36%
-10%
50 – Central region
-25%
-44%
-21%
-4%
60 – East central region
-29%
-37%
-5%
6%
70 – Southwest region
-34%
-34%
-25%
3%
80 – South central region
-28%
-40%
-14%
12%
90 – Southeast region
-32%
-39%
-6%
9%
State Average
-32%
-37%
-32%
-10%
2012: Crop Yield Response to Drought for Ohio by State Total and Crop Reporting District (CRD). Percentage reduction of 2012 yields compared to the average of the three previous years (2009-2011). Data from USDA-NASS.
Crop changes – 2012
Crop Reporting District
Corn
Corn Silage*
Soybean
Wheat
10 – Northwest region
-27%
.
3%
7%
20 – Northcentral region
-19%
.
-7%
2%
30 – Northeast region
-15%
.
-3%
17%
40 – West central region
-27%
.
-7%
16%
50 – Central region
-26%
.
-16%
8%
60 – East central region
-27%
.
-19%
14%
70 – Southwest region
-35%
.
-16%
5%
80 – South central region
-28%
.
1%
-1%
90 – Southeast region
-23%
.
-7%
-4%
State Average
-26%
-18%
-7%
8%
*Corn silage data by ag district is not reported by NASS for 2009-2012.
Main takeaway
This is the beginning of the season, and it is too early to make accurate assessments of how much or how little impact on crop yields drought could have caused. Note that some of the drought potential impacts to this point in the 2023 season might have been moderated through different mechanisms (to some degree). Some of those moderating mechanisms can include 1) hybrid/variety selection (breeding programs have improved the genetics that we grow today), 2) adjusting planting dates (earlier or later to avoid dry periods, either early in the season or later as well), and 3) rainfall later in the season (this is probably the most relevant now, as rainfall in the rest of the season [higher water demand] will dictate what the outcomes are for this crop year, moderating early-season impacts).
When it comes to crop conditions and effects on yields, corn, and soybean are most affected if drought happens close to the flowering period, which is when the most amount of water is demanded by each crop. For additional information on how dry conditions can affect early crop establishment, access:
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Battle for the Belt: Episode 15
Episode 15 of Battle for the Belt is now available: https://www.youtube.com/watch?v=UTgin3qPtoU
In Episode 15, we have a conversation with Dr. Pierce Paul, Cereal Plant Pathology Specialist about corn disease concerns and scouting, along with a field update from the Northwest and Western research stations and an Allen County farmer who planted soybeans first.
Corn Disease Updates
At the early growth stages in corn, the main diseases that can be scouted for are Pythium, Fusarium, and Rhizoctonia. These diseases occur in cold and wet environments. These diseases can be observed by poor emergence or skips in the corn stand. To check for this disease in surviving plants, dig up the root and look for discoloration and damage, which would indicate seedling disease issues. Approaching growth stage V5 corn can show symptoms of Anthracnose with frequent rainfall, however, in Ohio Anthracnose is not known to be yield-limiting. Because of the recent dry weather, most diseases are not a problem but as we receive more rain, the environment can become conducive to disease growth. To decide if you need a fungicide application start scouting before tasseling, between V12 and V18 (12 and 18 collared leaves). Scout the field on a weekly to biweekly basis to monitor any presence and/or severity. Consult the field guide for disease-specific scouting here.
Battle For the Belt Location Updates
Planting date five was planted on June 8th at both the Northwest and Western research stations. These locations were very dry like the rest of the state, thankfully, a few days after the planting date five in each location received rain. Around the June 8th date, the corn and soybeans for planting date four had not emerged yet (planted on May 25th, both locations).
The Wooster location received over 2 inches of rain last week according to Table 1. The corn for planting date one, two, three, and four are at growth stages V5, V5, V4, and V3. Corn height has been affected by the weather. Planting date one has a stunted height with planting date three, being a stage behind is as tall as planting date one. With soybeans the growth stages for planting dates, one, two, three, and four are as follows: V3, V2, V2, and VC. Thus far planting date three in soybeans has had the best environment for growth at this location.
The Western Location continues to be the furthest along in stage with corn showcasing planting date one at V7, planting date two at V6, planting date three at V5, and planting date four at V3. With soybeans, the growth stages for planting date one, two, three, and four are as follows: V4, V3, V2, and VC. At this location, floppy corn syndrome was found in planting dates one and two. This syndrome occurs when the root system is not well developed. However, this particular disorder has not been found at other locations.The Northwest Research Station received the least amount of rain last week in comparison to the other locations (see Table 1.) The stand at this location for each planting date has been good. The corn stages are V7, V6, V5, and V3 for planting dates one, two, three, and four. The stages for soybeans in planting dates one, two, three, and four are as follows: V4, V3, V2, and VC.
As a recap, this research project includes five planting date windows, 1) Ultra early = late March to early April; 2) Early = mid to late April; 3) Normal = early to mid-May; 4) Late = late May-first week of June; and 5) Very late = mid to late June. The planting date five update for the Wooster location will come next week or so.
Keep following the ‘Battle for the Belt’ this growing season to learn more and get further updates! You can find the full video playlist of Battle for the Belt on the Ohio State Agronomy YouTube channel.
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Lep Monitoring Network Update #7 – Trap Counts for CEW and ECB (IA & NY)
Introduction
The Ohio Lep Network is continuing to monitor moth pests across Ohio. As we have begun our seventh week of monitoring, we are happy to begin reports for corn earworm (CEW) monitoring as well as continuing to monitor for European corn borer (ECB) IA and NY populations. As mentioned in our most recent Lep Network newsletter, monitoring for black cutworm (BCW) and true armyworm (AMW) for this season has come to a close. For more resources on these pests and many others, check out our website: https://aginsects.osu.edu
Closing Out Black Cutworm
While we are no longer reporting on black cutworm (BCW), it should be noted that data collected from Van Wert and Hardin Counties last week showed an increase in the average number of BCW moths trapped when compared to previous weeks. Van Wert had an average of 4.8 moths, and Hardin’s average was 3.3.
Chasing Down Corn Earworm
This is our first week monitoring the corn earworm (CEW). Five counties across Ohio monitored for CEW populations using eight total bucket traps. In total, three moths were reported (Figure 1).
Corn earworm is a common corn pest found across Ohio that feeds on corn, tomato, and certain legume fields opening its host to a number of threats, including feeding damage, molds, and an increased threat from birds. The adult moths (Figure 2) are drawn to corn fields that are in the early green silk stage to lay their eggs. Once the eggs hatch, they begin feeding on the ears of corn and threatening the crop (Figure 3). For more information about the Corn Earworm, check out a previous newsletter: https://agcrops.osu.edu/newsletter/corn-newsletter/2019-27/corn-earworm-field-corn-watch-molds
Corn Earworm Moth Map
June 12 – June 18, 2023
Figure 1. Average corn earworm moths (CEW) captured from June 12th to June 18th. The bold number on the left indicates the average number of moths captured. The second number on the right indicates the number of traps monitored in each county.
Figure 2. Corn earworm moth coloration. Photo Credit: Mark Dreiling, Bugwood.org
Figure 3. Corn earworm feeding on ear of corn. Photo Credit: Robert J. Bauernfeind, Kansas State University, Bugwood.org
Exploring the European Corn Borer
This is our fifth week monitoring the European corn borer with no variants (IA/NY) being reported from June 12th – June 18th. In total, six counties across Ohio are monitoring for both ECB IA and NY using 16 total wing traps (Figure 4).
The European Corn Borer (ECB) is a common corn pest in Ohio that readily prohibits the proper flow of nutrients within an affected corn stalk. The ECB pest will bore into a stalk of corn (Figure 5), cutting off the nutrient flow and exposing the host plant to a number of problems including stalk breakage, ear drop, and reduction in corn yield. Identifying these pests is the first step to preventing a serious loss in corn crops, see Figure 6 as a reference below. ECB is more commonly a later season moth, so we plan to see an increase in the numbers of both variations in the coming weeks. For more information about ECB please visit: https://aginsects.osu.edu/sites/aginsects/files/imce/ENT_15_14.pdf
European Corn Borer Moth Map
June 12 – June 18, 2023
Figure 4. Average European corn borer moths (ECB) captured from June 12th to June 18th, both IA & NY variants. The bold number on the left indicates the average number of moths captured. The second number on the right indicates the number of traps monitored in each county.
Figure 5. European Corn Borer hole in stalk of corn. Photo Credit: Mariusz Sobieski, Bugwood.org
Figure 6. European Corn Borer color variations on a leaf. Photo Credit: Adam Sisson, Iowa State University, Bugwood.org
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Dicamba Deadline Reminder
Crop progress is highly variable this year. Some early planted crops have emerged and have had decent growth following recent rains. Dry weather has delayed the emergence of some later planted crops. This means there will also be variability in growth stages, which can have implications for POST application timings. The deadline to apply dicamba over-the-top (OTT) in Ohio is coming soon. For OTT applications of the dicamba products labeled for this use, the cutoff is up to and through June 30th, or the labeled growth stage. Below are the cutoff dates and/or soybean growth stages for the different products.
- XtendiMax – R1 growth stage or through June 30th, whichever comes first.
- Engenia – no later than June 30th
- Tavium – V4 growth stage or through June 30th, whichever comes first.
A soybean plant is at the V4 growth stage when there are four open trifoliates. The R1 growth stage occurs when there is one open flower somewhere on the main stem. See here for detailed descriptions and pictures of soybean growth stages. Table 8 and table 18 of the weed control guide have information related to the maximum crop size and harvest intervals for POST applications in corn and soybean, respectively. As always, it’s important to scout fields before planning applications and follow the herbicide label guidelines.
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Keep an Eye on the Horizon for Dry Weather Insect Pests
While nobody knows what the future holds regarding weather, recent dry conditions have made people think about the potential for drought this summer. In field crops, certain insect pests tend to be worse under dry conditions – either because hot and/or dry weather favors their biology, reduces the impact of natural enemies that help control them [particularly insect-killing fungi], weakens the plants’ resistance to the insects or increases the physiological damage potential, or some combination of these factors. While you can’t control the weather, stepping up scouting efforts in drought conditions can help you control unexpected damage from these dry-weather insects.
In soybean, spider mites, and grasshoppers are commonly worse in drought. In corn, grasshoppers can increase but are unlikely to be numerous enough to affect yield; however, spider mites can be a problem. In alfalfa, potato leafhopper damage can be worse under dry conditions, largely because the plants are more prone to “hopper burn” when they are stressed.
A very important fact about spider mites is that many commonly used insecticides in the pyrethroid category [such as lambda-cyhalothrin (for example, Warrior) and esfenvalerate (for example, Asana)] are known to flare spider mite populations rather than control them [one exception is the pyrethroid active ingredient bifenthrin]. So under drought conditions, it is very important not to use such products either as tank-mixed insurance treatments (which can create a problem where there was none) or for mite control. For mite management, you will usually get the best results with a miticide product, such as abimectin (for example, Agri-Mek) in soybean and etoxazole (for example, Zeal) in corn and soy. These are typically more expensive but they are worth the extra cost if spider mites are a real problem.
For a comprehensive list of products labeled in different field crops, their active ingredients, and scouting/threshold guidance, download the Michigan/Ohio State Field Crop Insect Pest Management Guide at https://aginsects.osu.edu/extension-publications/msuosu-ipm-guide
What can you do right now? Be aware that in dry conditions early scouting efforts for these pests can pay off. Also, if much of the Midwest is affected by drought this summer, miticides may be hard to come by later – if these are products you want to have on hand, plan accordingly. And stay tuned to the C.O.R.N. newsletter for more scouting and management information on emerging field crop pests.
*Our use of certain product names is not a brand endorsement, but provided for examples of products containing certain active ingredients.
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.
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