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Estimating Yield Losses in Stressed Corn Fields

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Many corn fields are still silking (and some are just past the mid-vegetative stages)….so, it may seem a little early to discuss estimating grain yields. However, according to the most recent  NASS crop report, for the week ending Aug. 8, 2019,  25% of the corn crop has reached the dough stage (compared to 63% for the 5 year average). Corn growers with drought damaged fields and late plantings may want to estimate grain yields prior to harvest in order to help with marketing and harvest plans. Two procedures that are widely used for estimating corn grain yields prior to harvest are the YIELD COMPONENT METHOD (also referred to as the “slide rule” or corn yield calculator) and the EAR WEIGHT METHOD. Each method will often produce yield estimates that are within 20 bu/ac of actual yield. Such estimates can be helpful for general planning purposes.

1. THE YIELD COMPONENT METHOD was developed by the Agricultural Engineering Department at the University of Illinois. The principle advantage to this method is that it can be used as early as the milk stage of kernel development, a stage many Ohio corn fields have probably achieved. The yield component method involves use of a numerical constant for kernel weight which is figured into an equation in order to calculate grain yield. This numerical constant is sometimes referred to as a “fudge‑factor” since it is based on a predetermined average kernel weight. Since weight per kernel will vary depending on hybrid and environment, the yield component method should be used only to estimate relative grain yields, i.e. “ballpark” grain yields. When below normal rainfall occurs during grain fill (resulting in low kernel weights), the yield component method will OVERESTIMATE yields. In a year with good grain fill conditions (resulting in high kernel weights), the method will underestimate grain yields.

In the past, the YIELD COMPONENT METHOD equation used a “fudge factor” of 90 (as the average value for kernel weight, expressed as 90,000 kernels per 56 lb bushel), but kernel size has increased as hybrids have improved over the years. Dr. Bob Nielsen at Purdue University suggests that a “fudge factor” of 80 to 85 (85,000 kernels per 56 lb bushel) is a more realistic value to use in the yield estimation equation today. https://www.agry.purdue.edu/ext/corn/news/timeless/YldEstMethod.html

According to Dr. Emerson Nafziger at the University of Illinois under current drought stress “…. If there’s a fair amount of green leaf area and kernels have already reached dough stage, using 90 [as the “fudge-factor “] might be reasonable. It typically doesn’t help much to try to estimate depth of kernels at dough stage, when kernel depth is typically rather shallow anyway, especially if there are 16 or more kernel rows on the ear. If green leaf area is mostly gone, however, and kernels look like they may be starting to shrink a little, kernels may end up very light, and using 120 or even 140 [as the “fudge-factor”] might be more accurate”. http://bulletin.ipm.illinois.edu/article.php?id=1695.

Calculate estimated grain yield as follows:

Step 1. Count the number of harvestable ears in a length of row equivalent to 1/1000th acre. For 30‑inch rows, this would be 17 ft. 5 in.

Step 2. On every fifth ear, count the number of kernel rows per ear and determine the average.

Step 3. On each of these ears count the number of kernels per row and determine the average. (Do not count kernels on either the butt or tip of the ear that are less than half the size of normal size kernels.)

Step 4. Yield (bushels per acre) equals (ear #) x (avg. row #) x (avg. kernel #) divided by 90.

Step 5. Repeat the procedure for at least four additional sites across the field. Given the highly variable conditions present in many late planted and stressed fields, repeat the procedure throughout field as many times as you think appropriate, then calculate the average yield for all the sites to make a yield assessment of the entire field.

Example: You are evaluating a field with 30‑inch rows. You counted 24 ears (per 17′ 5″ = row section). Sampling every fifth ear resulted in an average row number of 16 and an average number of kernels per row of 30. The estimated yield for that site in the field would be (24 x 16 x 30) divided by 90, which equals 128 bu/acre.

NOTE: If there is extensive leaf firing and senescence and little green tissue evident, and kernels appear to be shrinking, using 120 or even 140 as the “fudge-factor” might be more appropriate. Making some assessments using both 90 and 120 can provide an idea of the range in yield possible.

2. THE EAR WEIGHT METHOD can only be used after the grain is physiologically mature (black layer), which occurs at about 30‑35% grain moisture (but this year with late planting it could be as high as 40%). Since this method is based on actual ear weight, it should be somewhat more accurate than the yield component method above. However, there still is a fudge factor in the formula to account for average shellout percentage.

Sample several sites in the field. At each site, measure off a length of row equal to 1/1000th acre. Count the number of harvestable ears in the 1/1000th acre. Weigh every fifth ear and calculate the average ear weight (pounds) for the site. Hand shell the same ears, mix the grain well, and determine an average percent grain moisture with a portable moisture tester.

Calculate estimated grain yield as follows:

Step A) Multiply ear number by average ear weight.

Step B) Multiply average grain moisture by 1.411.

Step C) Add 46.2 to the result from step B.

Step D) Divide the result from step A by the result from step C.

Step E) Multiply the result from step D by 1,000.

Example: You are evaluating a field with 30‑inch rows. You counted 24 ears (per 17 ft. 5 in. section). Sampling every fifth ear resulted in an average ear weight of 1/2 pound. The average grain moisture was 30 percent. Estimated yield would be [(24 x 0.5) / ((1.411 x 30) + 46.2)] x 1,000, which equals 135 bu/acre.

Because it can be used at a relatively early stage of kernel development, the Yield Component Method may be of greater assistance to farmers trying to make a decision about whether to harvest their corn for grain or silage. Since drought stress conditions and late planting in some fields may result in poorly filled small ears, there may be mechanical difficulties with combine harvest efficiency that need to be considered.

References

Nafziger, E. 2012. Estimating Yields of Stressed Corn. The Bulletin, Univ of Illinois. http://bulletin.ipm.illinois.edu/article.php?id=1695 [URL verified Aug. 2019].

Nielsen, RL. 2018.  Estimating Corn Grain Yield Prior to Harvest. Corny News Network, Purdue University. https://www.agry.purdue.edu/ext/corn/news/timeless/YldEstMethod.html (URL verified Aug. 2019).

Topics:
Corn Growth and Development; corn
Author(s):

Peter Thomison

ABOUT THE C.O.R.N. NEWSLETTER

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.

“Ask the Expert” Area Seeks to Help Farmers Mitigate the Challenges of 2019 at this year’s Farm Science Review

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Each year, faculty and staff of The Ohio State University address some of the top farm management challenges which Ohio farmers are facing during the “Ask the Expert” sessions held each day at the Farm Science Review at the Molly Caren Agricultural Center near London, Ohio.  The 20 minute “Ask the Expert” presentations at Farm Science Review are one segment of the College of Food, Agricultural, and Environmental Sciences (CFAES) comprehensive extension education efforts during the three days of the Farm Science Review which will be held September 17-19 in London, Ohio.

The 2019 growing season has particularly challenging for Ohio growers and producers due to the historic rainfall in Ohio. Twenty-seven of this year’s “Ask the Expert” sessions will feature discussions aimed at helping farmers mitigate the challenges faced by agricultural producers in 2019 and beyond.   Our experts will share science-based recommendations and solutions to the issues growers are facing regarding weather impacts, tariffs, and low commodity prices.   Producers are encouraged to attend one or more of the sessions throughout the day.

The sessions will take place in the Ohio State Area in the center of the main Farm Science Review exhibit area located at 426 Friday Avenue. The farm management sessions will be featured include:

Tuesday, September 17, 2019

“Tax Strategies Under the New Tax Law” presented by Barry Ward 10:00 – 10:20 a.m.

“Climate Smart- Weather, Climate & Extremes-Oh My!” presented by Aaron Wilson 10:20 – 10:40 a.m.

 “Before the Pearly Gates- Getting Your Farm Affairs in Order” presented by David Marrison 10:40 – 11:00 a.m.

“Crop Inputs & Cash Rent Outlook for 2020” presented by Barry Ward 11:00 – 11:20 a.m.

“Farm Stress-We Got Your Back” presented by Dee Jepsen 11:20 – 11:40 a.m.

“Farm Income Forecasts: Are Farmers Experiencing Financial Stress?”presented by Ani Katchova  12:20 – 12:40 p.m.

“How Much Money Stayed on the Farm? 2018 Ohio Corn & Soybean Production Costs” presented by Dianne Shoemaker  12:40 – 1:00 p.m.

“Where Are We on U.S. Trade Policy” presented by Ian Sheldon 1:00 – 1:20 p.m.

“Farm Accounting: Quicken or Quickbooks” presented by Wm. Bruce Clevenger  1:20 – 1:40 p.m.

“Commodity Markets – Finding Silence in the Noise” by Ben Brown 1:40 – 2:00 p.m.

Wednesday, September 18, 2019

“Climate Smart- Weather, Climate & Extremes-Oh My!” presented by Aaron Wilson 10:00 – 10:20 a.m.

“Solar Leasing Options” presented by Peggy Hall & Eric Romich 11:00 – 11:20 a.m.

 “Where Are We on U.S. Trade Policy” presented by Ben Brown 11:20 – 11:40 a.m.

“Crop Inputs & Cash Rent Outlook for 2020” presented by Barry Ward 12:00 – 12:20 p.m.

“Commodity Markets – Finding Silence in the Noise” by Ben Brown 12:20 – 12:40 p.m.

 Public Perception Risk: Building Trust in Modern Agriculture by Eric Richer 12:40 – 1:00 p.m.

“Farm Stress-We Got Your Back” presented by Dee Jepsen 1:00 – 1:20 p.m.

“How Much Money Stayed on the Farm? 2018 Ohio Corn & Soybean Production Costs” presented by Dianne Shoemaker 1:20 – 1:40 p.m.

 “Tax Strategies Under the New Tax Law” presented by Barry Ward 2:00 – 2:20 p.m.

 “Using On-Farm Research to Make Agronomic and Return on Investment Decisions” presented by Sam Custer 2:40 – 3:00 p.m.

Thursday, September 19, 2019

“Farm Stress-We Got Your Back” presented by Dee Jepsen 10:20 – 10:40 a.m.

“Tax Strategies Under the New Tax Law” presented by Barry Ward 10:40 – 11:00 a.m.

 “Solar Leasing Options” presented by Peggy Hall & Eric Romich   11:20 – 11:40 a.m.

 “Commodity Markets – Finding Silence in the Noise” by Ben Brown 11:40 – Noon

 “Crop Inputs & Cash Rent Outlook for 2020” presented by Barry Ward 12:00 – 12:20 p.m.

 “Where Are We on U.S. Trade Policy” presented by Ben Brown 12:40 – 1:00 p.m.

 “How Much Money Stayed on the Farm? 2018 Ohio Corn & Soybean Production Costs” presented by Dianne Shoemaker 1:40 – 2:00 p.m.

The complete schedule for the Ask the Expert sessions and other events at the 2019 Farm Science Review can be found at: https://fsr.osu.edu/

Additional farm management information from OSU Extension can be found at ohioagmanager.osu.edu or farmoffice.osu.edu

Source:

David Marrison, OSU Extension

740-622-2265

Marrison.2@osu.edu

#leanonyourlandgrant

Brown County 4-H Craft And Vendor Show

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The annual Fall 4-H Craft/Vendor Show will be held on October 26, 2019 from 9:00 A.M. – 3:00 P.M. The event will be on the Brown County Fairgrounds in Rhonemus Hall. All proceeds to benefit Brown County 4-H. Anyone interested in being a vendor can find registration forms here: https://brown.osu.edu/FallShowAndRun

We are working to add other events to the day. Updates will be added as they are confirmed.

 

Tax Planning in an Unusual Year – Prevented Planting Indemnity Payments, Market Facilitation Payments and Cost-Share Payments

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by: Barry Ward, Leader, Production Business Management & Director, OSU Income Tax Schools

Prevented Planting Crop Insurance Indemnity Payments

With unprecedented amounts of prevented planting insurance claims this year in Ohio and other parts of the Midwest, many producers will be considering different tax management strategies in dealing with this unusual income stream. In a normal year, producers have flexibility in how they generate and report income. In a year such as this when they will have a large amount of income from insurance indemnity payments the flexibility is greatly reduced. In a normal year a producer may sell a part of grain produced in the year of production and store the remainder until the following year to potentially take advantage of higher prices and/or stronger basis. For example, a producer harvests 200,000 bushels of corn in 2019, sells 100,000 bushels this year and the remainder in 2020. As most producers use the cash method of accounting and file taxes as a cash based filer, the production sold in the following year is reported as income in that year and not in the year of production. This allows for flexibility when dealing with the ups and downs of farm revenue.

Generally, crop insurance proceeds should be included in gross income in the year the payments are received, however Internal Revenue Code Section (IRC §) 451(f) provides a special provision that allows insurance proceeds to be deferred if they are received as a result of “destruction or damage to crops.”

As prevented planting insurance proceeds qualify under this definition, they can qualify for a 1 year deferral for inclusion in taxable income. These proceeds can qualify if the producer meets the following criteria:

  1. Taxpayer uses the cash method of accounting.
  2. Taxpayer receives the crop insurance proceeds in the same tax year the crops are damaged.
  3. Taxpayer shows that under their normal business practice they would have included income from the damaged crops in any tax year following the year the damage occurred.

The third criteria is the sometimes the problem. Most can meet the criteria, although if producers want reasonable audit protection, they should have records showing the normal practice of deferring sales of grain produced and harvested in year 1 subsequently stored and sold in the following year. To safely “show that under their normal business practice they would have included income from the damaged crops in any tax year following the year the damage occurred” the taxpayer should follow IRS Revenue Ruling 75-145 that requires that he or she would have reported more than 50 percent of the income from the damaged or destroyed crops in the year following the loss. A reasonable interpretation in meeting the 50% test is that a farmer may aggregate the historical sales for crops receiving insurance proceeds but tax practitioners differ on the interpretation of how this test may be met.

One big problem with these crop insurance proceeds is that a producer can’t divide it between years. It is either claimed in the year the damage occurred and the crop insurance proceeds were received or it is all deferred until the following year. The election to defer recognition of crop insurance proceeds that qualify is an all or nothing election for each trade or business IRS Revenue Ruling 74-145, 1971-1.

Tax planning options for producers depend a great deal on past income and future income prospects. Producers that have lower taxable income in the last 3 years (or tax brackets that weren’t completely filled) may want to consider claiming the prevented planting insurance proceeds this year and using Income Averaging to spread some of this year’s income into the prior 3 years. Producers that have had high income in the past 3 years and will experience high net income in 2019 may consider deferring these insurance proceeds to 2020 if they feel that this year may have lower farm net income.

Market Facilitation Payments

When the next round(s) of Market Facilitation Payments (MFPs) are issued, they will be treated the same as the previous rounds for income tax purposes. These payments must be taken as taxable income in the year they are received. As these payments are intended to replace income due to low prices stemming from trade disputes, these payments should be included in gross income in the year received. As these payments constitute earnings from the farmers’ trade or business they are subject to federal income tax and self-employment tax. Producers will almost certainly not have the option to defer these taxes until next year. Some producers waited until early 2019 to report production from 2018 and therefore will report this income from the first round of Market Facilitation Payments as taxable income in 2019.

Producers will likely not have the option of delaying their reporting and subsequent MFP payments due to the fact they are contingent upon planted acreage reporting of eligible crops and not yield reporting as the first round of MFP payments were.

Cost Share Payments

Increased prevented planting acres this year have many producers considering cover crops to better manage weeds and erosion and possibly qualify for a reduced MFP. There is also the possibility that producers will be eligible for cost-share payments via the Natural Resources Conservation Service for planting cover crops. Producers should be aware that these cost-share payments will be included on Form 1099-G that they will receive and the cost-share payments will need to be included as income.

You are advised to consult a tax professional for clarification of these issues as they relate to your circumstances.

 

Find more articles at https://u.osu.edu/ohioagmanager/

EPA Takes Action to Provide Accurate Risk Information to Consumers, Stop False Labeling on Products

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EPA Takes Action to Provide Accurate Risk Information to Consumers, Stop False Labeling on Products

08/08/2019
Contact Information: 

EPA Press Office (press@epa.gov)

WASHINGTON (Aug. 8, 2019) – EPA is issuing guidance to registrants of glyphosate to ensure clarity on labeling of the chemical on their products. EPA will no longer approve product labels claiming glyphosate is known to cause cancer – a false claim that does not meet the labeling requirements of the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA). The State of California’s much criticized Proposition 65 has led to misleading labeling requirements for products, like glyphosate, because it misinforms the public about the risks they are facing. This action will ensure consumers have correct information, and is based on EPA’s comprehensive evaluation of glyphosate.

“It is irresponsible to require labels on products that are inaccurate when EPA knows the product does not pose a cancer risk. We will not allow California’s flawed program to dictate federal policy,” said EPA Administrator Andrew Wheeler. “It is critical that federal regulatory agencies like EPA relay to consumers accurate, scientific based information about risks that pesticides may pose to them. EPA’s notification to glyphosate registrants is an important step to ensuring the information shared with the public on a federal pesticide label is correct and not misleading.”

In April, EPA took the next step in the review process for glyphosate. EPA found – as it has before – that glyphosate is not a carcinogen, and there are no risks to public health when glyphosate is used in accordance with its current label. These scientific findings are consistent with the conclusions of science reviews by many other countries and other federal agencies.

On Feb. 26, 2018, the United States District Court for the Eastern District of California issued a preliminary injunction stopping California from enforcing the state warning requirements involving glyphosate’s carcinogenicity, in part on the basis that the required warning statement is false or misleading. The preliminary injunction has not been appealed and remains in place.

California’s listing of glyphosate as a substance under Proposition 65 is based on the International Agency on the Research for Cancer (IARC) classifying it as “probably carcinogenic to humans.” EPA’s independent evaluation of available scientific data included a more extensive and relevant dataset than IARC considered during its evaluation of glyphosate, from which the agency concluded that glyphosate is “not likely to be carcinogenic to humans.” EPA’s cancer classification is consistent with many other international expert panels and regulatory authorities.

Registrants with glyphosate products currently bearing Proposition 65 warning language should submit draft amended labeling that removes this language within 90 days of the date of the letter.

For more information about EPA’s comprehensive evaluation of glyphosate, visit https://www.regulations.gov/document?D=EPA-HQ-OPP-2009-0361-0073.

To read the notice to registrants, click here.

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Commercial Pesticide Re-certification Opportunities

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Upcoming commercial pesticide applicator recertification opportunity: September 17th at The Ohio Department of Agriculture Office in Reynoldsburg, OH. This recertification will cover, CORE, 7, 10a, 10b, 10c and 10d. Registration details and schedule can be found at OhioPMArecert

 

 

 

 

The 2020 commercial recertification conference dates can be found at 2020 Commercial Conferences

January 9 (Thursday)
Dayton Convention Center
Dayton, Ohio		 January 24 (Friday)
Kalahari Conference Center
Sandusky, Ohio
February 12 (Wednesday)  
John S. Knight Center
Akron, Ohio		 February 27 (Thursday) 
Columbus Convention Center
Columbus, Ohio

Ohio House Passes Senate Bill 57 to Decriminalize Hemp and License Hemp Cultivation

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Now that the Ohio House passed Senate Bill 57 to decriminalize hemp and license cultivation, what’s next for Ohio?

 

1. Governor Mike DeWine must sign the bill

2. The Ohio Department of Agriculture must create rules and a regulatory program

3.Ohio’s Joint Committee on Agency Rule Review (a legislative committee) must approve ODA’s rules and program

4.USDA must approve the state program

5. The Ohio Department of Agriculture must start accepting license applications

6. Producers must apply for licenses

7. The Ohio Department of Agriculture must approve applications from producers

7. Producers must find seed (and buyers of the final product)

By: Evin Bachelor, Law Fellow, The Ohio State University Agricultural and Resource Law Program.

To learn about the basics of hemp production, check out this facsheet from the University of Kentucky An Introduction to Industrial Hemp and Hemp Agronomy

 

 

 

Delayed Corn Planting the Disease Risk in Corn

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Disease Risk. In Ohio, several foliar diseases are of greater concern in late-planted corn for a number of reasons, including: 1 – for diseases like gray leaf spot (GLS), northern corn leaf blight (NCLB), and eye spot that are caused by pathogens that overwinter in corn stubble, delayed planting allows more time for inoculum (spores) to buildup, especially in no-till, corn-on-corn fields and 2 – for diseases like common and southern rust that are caused by pathogens that do not overwinter in Ohio, planting late allows more time for spore for blow up from southern states. So, with late planting, not only are more spores likely to be available to infect the crop, they are also more likely to infect the crop at an earlier growth stage and under conditions that are more favorable for disease development. Let us use gray leaf spot as an example. In a “normal” year, although lesions may develop early in the season, this disease typically takes off and spreads after pollination (VT/R1) when the number of spores in the air is high and the weather becomes favorable for infection. Depending on where you are in the state, VT/R1 usually occurs sometime in mid-July. Planting late does not prevent spores from building up or conditions from becoming favorable for the gray leaf spot fungus to infect plant in mid-July, however, the primary difference it that instead of infecting plants at the VT/R1 growth state, the fungus will be infecting plants at a much earlier growth stage, V8-V12, for instance. If the hybrid is susceptible and conditions become favorable, high levels of infection at V8-V12 will result in greater and more rapid diseases development, and consequently, greater damage to the upper leaves before grain-fill is complete. This is also true for NCLB, eye spot, and southern rust.

 

So, what should I do: Given the scenario described above, the obvious questions are “should I spray my field e arlier this year?” and “will I see a greater benefit from treating my field at V10 or V12 than at VT/R1?” Remember, regarding of when infections occur, disease development and yield loss still depend on how susceptible the hybrid is and how favorable weather conditions become, particularly during pollinations and early grain-fill. Since 2010, we have mimicked the scenario of early infection by planting highly susceptible hybrids into no-till fields that were planted back-to-back-to-back to corn. These were fields with very high spore numbers. We then compared early (V5-7) applications of several different fungicides to VT/R1 and V5+R1 applications. In all cases, we found that applications made at silking (R1) or tasseling (VT) were the most effective in terms of foliar disease control and yield response. Although we did see a yield benefit to treatments applied between V5 and V10 in some years, the average yield increase was often lower and more variable with the early applications compared to the VT/R1 applications. Similarly, on average, the yield response was much lower and more variable when fungicides were used under low disease pressure or in the absence of foliar diseases. Over the years we have found that fungicides tend to be most profitable and the yield response most consistent when conditions are favorable for disease development and susceptible hybrids are planted, especially in a no-till, continuous-corn field. Follow the labels and keep your eyes on the fungicide price and application cost when making a decision. Below are the guidelines commonly used for making fungicide application decisions:

  • Susceptible hybrids: If disease symptoms are present on the third leaf below the ear or higher on 50% of the plants examined, a fungicide is recommended.
  • Intermediate hybrids:  If disease symptoms are present on the third leaf below the ear or higher on 50% of the plants examined, AND the field is in an area with a history of foliar disease problems, the previous crop was corn, and there is 35% or more surface residue, and the weather is warm and humid through July and August, a fungicide is recommended.
  • Resistant hybrids:  Fungicide applications generally are not recommended.

 

But this year is very different! Indeed, it is, and the approach for scouting for diseases will have to be different as well. You will have to scout fields more carefully and frequently, and look for multiple diseases developing simultaneously  – the crop is developing fast, and diseases will likely spread quickly as well, if the weather is favorable. Look for regular diseases like eye spot, GLS, NCLB and common rust; be on the lookout for explosives and damaging diseases like southern rust; and keep your eyes out for emerging diseases like tar spot.  Eye Spot – Small circular to oval lesions, with a tan to grayish center and a yellowish halo, beginning on the leaves below the ear and progressing up the plant. This disease tends to be very common in no-till fields, and is favored my moderate temperatures and abundant rainfall. Gray leaf spot (GLS) – Grayish, rectangular lesions that develop first on the leaves below the ear. This disease usually begins developing close to or after tasseling and is favored by warm, humid conditions. Like eye spot, gray leaf spot also tends to be more of a concern in no-till corn fields. Northern Corn Leaf Blight (NCLB) – This is another residue-borne disease that develops best under wet, humid conditions. However, it prefers slightly cooler conditions than those favorable for the development of gray leaf spot. Lesions are large, cigar-shaped and gray-green to tan in color. Common Rust – This is not a residue-borne disease, as such, its development is not affected by crop rotation and tillage. Spores are blown in from the south. Like northern corn leaf blight, it develops best under cool, humid conditions. The symptoms are large, cinnamon-brown, elongated pustules scattered over both surfaces of the leaf. Do not confuse common rust with the more damaging Southern Rust which produces smaller, circular, reddish-orange pustules, predominantly on the upper surface of the leaf, and occasionally on the stems and husks. Southern rust develops best under warm, humid conditions. Tar spot is new to Ohio. It was detected for the first time in 2018. The symptoms are raised circular, brown to black lesions scattered across both surfaces of the leaf. It is favored by moderate temperatures, high relative humidity, and extended periods of leaf wetness, and is often more severe in no-till, continuous-corn fields.

Topics:
Corn Disease

Author(s):

Pierce Paul