C.O.R.N. Newsletter: 2019-41
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Choosing Varieties & Hybrids for 2020 - Check Disease Resistance Ratings
The seed suppliers want your early orders and the catalogues are all spread out on the tables. Now to begin the process of choosing the best variety or hybrid for your fields that can hold up to the all of the challenges facing soybeans and corn in Ohio. Our recommendation is to first focus on the disease and insect scores. Every company uses a different scale based on 1 to 10 – but for some companies 1 is best and for others, 10 best – so first read the fine print. In addition, some companies use a distributive disease rating scale, using words like “excellent disease package,” “good disease package,” or “poor.” While this scale is unclear as to which specific disease the hybrid is most resistant to, it can still be used as a guide for hybrid/variety selection. For instance, a hybrid listed as having an “excellent disease package” should be less susceptible to the primary diseases than one listed as having a “good disease package.” Next step – what key diseases and insect pests do we need to focus on.
Soybeans: the four diseases that impact Ohio farmers the most are: Phytophthora (on poorly drained soils), Frogeye leaf spot (continuous soybean fields from central Ohio-south), Sclerotinia (fields with poor air drainage – Northeast and Eastern regions), and SCN (more than 50% of fields now have detectable populations of SCN – with more than 7% in severely high populations).
Phytophthora root and stem rot. This pathogen, Phytophthora sojae, can be found in most fields in Ohio but causes disease when those fields are saturated with rains for 24 hours or more. Under these conditions highly susceptible varieties can have 100% yield loss. The heavy clays of Northwest Ohio are particularly prone to this disease. During 2019, we detected Phytophthora stem rot over a broader geographic region due to the amount of rain. In the seed catalogues, there are two ratings for resistance, 1) a listing of a Rps gene and 2) a quantitative resistance score on a 1 to 9 scale. The Rps genes were the first line of defense and have been used since the 1960s (Rps1a was the first). Based on recent check-off funded research, we can confirm that most fields in Ohio have populations of P. sojae, where these genes are no longer 100% effective. They might work in one spot in the field, but not 2 feet away. The next line of soybean defense is the quantitative resistance, which is many, many genes working together to limit the growth of the pathogen. Much like a teenager that is immune to all of the badgering to do their chores – it isn’t bothered at all by the presence of the pathogen. This quantitative resistance has been called many things in the seed catalogues: partial resistance, field resistance, and tolerance. Our best varieties have scores of 3 on a scale of 1 to 10 where 1 is very high resistance (really an effective Rps gene) and 10 is dead. Focus on the best score rating for that seed company.
Frogeye leaf spot. This has now become a recurring problem for soybeans in southern up to Central Ohio. High levels of inoculum (lots of leaf spots) in the fall that can overwinter in Ohio, so this is especially important for those fields that are continuous soybean. The first thing is if you had Frogeye at the end of the season in 2019, please do not plant the same variety back in that field. I do that to create the best opportunity for our research plots to develop disease for fungicide studies, and since I have that covered, you don’t need to do that. Any frogeye in fields in 2019 (conditions were not as favorable as previous years) means it's time to choose something with better resistance scores. A resistant cultivar will not develop frogeye, so no yield hit and no added input costs for fungicides if conditions are favorable for disease to develop.
Sclerotinia stem rot. The infections for this disease occur during flowering under conditions of cool temperatures (70s F) and high humidity. High plant population and poor air drainage can also favor this disease. Resistance to this pathogen, Sclerotinia sclerotiorum, is also quantitative (many genes) and some are associated with limiting pathogen growth but also with longer internodes to help with disease escape. The structure, sclerotia, looks like a mouse or rat dropping, and can survive for long periods of time if they are buried. This is one soybean disease where no-till can favor the degradation of the sclerotia.
Soybean Cyst Nematode. This nematode continues to expand in the number of fields it can be detected in (> 50%) in Ohio. More importantly, we are also identifying fields with super high numbers of SCN (7% of those sampled during 2018 & 2019)! It is very important to continue to purchase varieties with SCN resistance. This is a success story. Planting soybean varieties with resistance has kept this nematode at very low levels for over 20 years. Based on earlier reports from the ‘90s, it had the potential to become a major problem, but then the companies all worked hard to provide new varieties with SCN resistance. Now, as you would expect, similar to Phytophthora, where the same resistance has been deployed for 20 years, we do have a number of fields in Ohio where the SCN populations are adapting to PI 88788 or Peking or both sources of resistance. Interestingly, not like the Rps genes of Phytophthora where they work or they don’t, SCN adapts slowly by increasing the number of successful feeding sites on the roots of resistant plants. So early in the process, we don’t see the decline in SCN numbers when soil tests are collected and yields begin to drop. Later in the process, increases in SCN occur overall in the field and yield loss is similar to that of a susceptible variety. We are in the midst of wrapping up this statewide survey as part of the SCN coalition ( https://www.thescncoalition.com/ ) to assess where SCN is in Ohio and if it has adapted. Summary results from this for Ohio will be coming in April.
Gray leaf spot (GLS) of corn. This is still the most frequently occurring foliar disease of corn in Ohio and neighboring states, but thanks to genetic resistance, the impact of this disease is low in most years. On rare occasions when susceptible hybrids are planted under warm, humid conditions in river-bottom fields, yield loss can exceed 50%. Resistance in the case of GLS does not mean “no disease,” it means less disease or low disease severity. Compared to susceptible hybrids, fewer and smaller lesions develop on resistant hybrids, leading to slower disease spread from the lower to the upper leaves. Some companies rank their hybrids for resistance to GLS on a 1 to 9 scale, with 1 being most resistant and 9 being most susceptible. However, some companies do the opposite, with hybrids with higher scores being more resistant than those with low scores.
Northern Corn Leaf Blight (NCLB). Like GLS, this is one of the most common leaf diseases of corn in Ohio, and over the last few years, NCLB has been more severe than GLS. Two types of resistance are available to protect against races of the fungus that cause NCLB: partial resistance (non-race specific), which protects against all known races of the fungus, and race-specific resistant, which is controlled by single Ht genes and, as the name suggests, protects against specific races of the pathogen. Partial resistance is expressed as a reduction in the number and size of the lesions, and the amount of spores produced in the lesions, as well as an increase in the length of time it takes for new lesions to develop and a new crop of spores to be produced. Race-specific resistance is controlled by one or more Ht genes, such as Ht1, Ht2, Ht3, and HtN. Resistance conferred by Ht1, Ht2, and Ht3 is expressed as small chlorotic lesions with limited sporulation, whereas resistance conferred by HtN results in fewer, smaller lesions, similar to what is observed with partial resistance. For years, races 0 and 1 were the most predominant races of the NCLB fungus in Ohio. If we assume that these races are still the most prevalent, the fact that we continue to see susceptible reactions on multiple hybrids at multiple locations across the state suggests that we are either planting hybrids without Ht genes (susceptible to races 0 and 1) or with Ht1 only (susceptible to race 1). Avoid planting hybrids without Ht resistance. Click here for more on NCLB resiatance: https://agcrops.osu.edu/newsletter/corn-newsletter/select-hybrids-resistance-northern-corn-leaf-blight-how-does-it-work
For diseases like ear rots for which there is very little information in seed catalogs on disease resistance, use your own experience as a guide for making hybrid selection. For instance, if the hybrid you planted this or last season (or five seasons ago) ended up with high levels of Gibberella ear rot and vomitoxin, it means that the hybrid is susceptible. Avoid planting it in that same field next year. Also, since resistance may change over time, your experience with a hybrid may be just as good as or even better than the information in some seed catalogs when it comes to disease susceptibility.
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What’s in my Corn? Insect Management Traits in Corn Hybrids
Corn hybrid selection is about more than maturity and agronomic properties. Many corn hybrids also come with a package of Bt traits for the management of various insects below-ground (for example corn rootworm) and above-ground (for example, corn borer) pests. These traits can add substantially to the cost of the seed so it’s worth evaluating which ones you really need. In fields without a consistent history of insect pest pressure Bt traits are an added cost that likely won’t pay for itself. Sometimes you only need protection against soil pests, sometimes against above-ground pests, and sometimes neither. But how do you know what Bt traits the various hybrids contain and what insects they are meant to manage? This can be confusing or hard to figure out.
There is an excellent resource available to help with this – the Handy Bt Trait Table. This invaluable reference is written by Dr. Chris DiFonzo at Michigan State University and is updated every year. In one place it lists what types of Bt are present in which corn hybrids, what insects they are targeted for, and for which insects resistance to a given Bt protein has been documented (leading to a loss of efficacy). You can find the Handy Bt Trait Table linked on the OSU Ag Insects website. Check it out to learn which Bt traits are in which hybrids so you can make the most informed and economical decisions for your farm.
https://aginsects.osu.edu/bt-corn-trait-table
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Winter Application of Manure - Remember Setbacks
Some Ohio livestock producers will be looking to apply manure to farm fields frozen enough to support application equipment. Permitted farms are not allowed to apply manure in the winter unless it is an extreme emergency, and then movement to other suitable storage is usually the selected alternative. Thus, this article is for non-permitted livestock operations.
In the Grand Lake St Marys watershed, the winter manure application ban from December 15th to March 1st is still in effect. Thus, no manure application would normally be allowed from now until March 1st.
In the Western Lake Erie Basin (WLEB) watershed, the surface application of manure to frozen and snow-covered soils require there to be a growing crop in the field. This could be a pasture, alfalfa, clover, ryegrass or a rape crop. There must be enough vegetation visible to provide a 90% cover of residue and growing vegetation. Radishes and oats would not qualify as a growing crop as both are typically winter killed. Manure can be applied to fields without growing crops if the manure is incorporated at the time of application or incorporated within 24 hours of application.
The rainfall rule for surface manure application in the WLEB is a weather forecast saying “not greater than a 50% chance of a half inch or more of rain in the next 24 hours.” It is advisable to print out the weather forecast when you start applying manure so you have the needed proof if an unexpected storm drenches the area. Weather.gov is the most commonly accepted website for this forecast. On this web page, you can type in the zip code for a seven-day forecast. On the lower right-hand side of the seven-day forecast page, is an hourly weather forecast that will provide a 48-hour weather forecast graph.
Winter manure application rates should follow the NRCS 590 standards, which limit solid manure application amounts to five tons per acre and liquid manure application amounts to 5,000 gallons per acre. These have 200 foot setback distances from ditches, streams and creeks and must be on slopes of less than 6% and less than 20 acre areas in size without additional buffers. These setbacks exist because as snow melts, it can carry manure to streams and ditches. These 200 foot setback distances apply to both liquid and solid manure application. In recent years there have been several fines levied against livestock producers applying manure too close to ditches and streams.
For liquid manure applicators, examine fields for tile blowouts, monitor tile outlets before, during, and after manure application and any other situations that might allow manure to reach surface waters.
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Late Planted Corn Performance Test Results – How Did They Turn Out?
Performance data for the Ohio Corn Performance Test (OCPT) site at Upper Sandusky planted June 22 was not presented in the 2019 Ohio Corn Performance Test bulletin because of a late harvest (Nov. 26). However, results for this test are now available online at: http://oardc.osu.edu/corntrials/
Although a June 22 planting date is very atypical, many corn growers in northwest Ohio were planting well into June this year. There was considerable uncertainty as to what to expect from such a late planting, much less whether a grain crop was achievable.
The Upper Sandusky results provide insight on corn performance associated with late June planting dates. Grain yields in the early and full season tests averaged 226 and 222 bu/A, respectively. The results demonstrate that corn planted in late June can produce high yields under favorable growing conditions. The Upper Sandusky test was characterized by limited weather stress, timely rains during grain fill, and negligible pest injury. Despite the late November harvest, stalk lodging averaged less than 2%. However, these exceptional yields were associated with high grain moisture levels and low test weights. Harvest grain moisture averaged 30.1% and 33.7% for the early and full season tests, respectively and test weight averages for the early and late tests ranged from 49.9 to 50.5 lbs./A.
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“Ultra-early” Corn Performance
Confronted with June planting dates, some Ohio corn growers planted hybrids with relative maturity ratings earlier (less than 102 days) than those of our commonly grown maturities. At the Hoytville OCPT test site, we evaluated 27 ultra-early hybrids with maturities ranging from 93-101 days. Yields averaged 190 bu./A and ranged from 163 to 219 bu/A; harvest grain moisture averaged 19.3 and ranged from 18.3-20.3%; and test weight averaged 56.6 and ranged from 53.3-58.5. In contrast, a 107 day commonly grown maturity hybrid included as a check yielded 220 bu/A with a 22.9 % harvest moisture and test weight of 51 lb/A. The Hoytville test site planted June 12 and harvested November 18, benefited from favorable growing conditions with timely rains. Pest injury was negligible. Several hybrids were subject to severe animal damage and not considered in this performance overview.
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Final Reminder: 2019 Yield Survey
By: CFAES Ag Crisis Taskforce
Normal planting dates for Ohio range from mid-April to the end of May. This season was quite different when planting for both crops was delayed until late May and stretched into June and even July across many parts of Ohio. We found ourselves grasping for any information we could find including 1) how much of an effect late planting dates would have on yield, and 2) what, if anything, we should change in management of these late planted crops. The historical planting date information we did have was somewhat helpful, but we did not have any data on what could happen when planting is delayed into the second half of June nor July.
While it may be tempting to write off this year as a fluke from which there are no real lessons to be learned, there is a growing body of data from climatologists that suggest that this is a beginning of a trend. What we have is a giant, unplanned and involuntary trial being conducted by Ohio corn and soybean farmers this year. This experiment can help us understand the ramifications of how planting date and hybrid/variety maturity affected overall yields, as well as pinpoint where further research is needed to fill the gaps in knowledge for future management decisions. To accomplish these goals, we plan to collect a small amount of data on a large number of fields, which can be used to provide baseline information to share how to manage these crops under similar weather events in the future.
To do this, we have a simple request: share your information with us. We ask only for the following information from as many fields as possible:
- County where the field is located
- Crop: corn or soybean
- Planting date
- Harvest date
- Maturity rating (corn relative maturity (days RM); soybean maturity group) of crop planted
- Yield
- Harvest moisture
- Test weight
Information on weather or management can be added, but this is optional. The information can be submitted to us in one of two ways: 1. Follow this link, go.osu.edu/yield19, to an online form with which you can report one field at a time or 2. Print or download a paper form at go.osu.edu/yield19form, fill it out for as many fields as possible, and send a copy via email to Elizabeth Hawkins (Hawkins.301@osu.edu). We will collect this data from farmers until December 31, 2019.
Additional notes:
1. Don’t forget to include early or normal planting dates too. This will help us capture the breadth of the crop in 2019. We want data across a wide range of planting dates, not just late plantings
2. If a field has drowned-out spots where there’s no yield, either don’t use the field average or estimate yield from yield monitor data from parts of the field where stands were representative.
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2019 Northwest Ohio Corn Silage Test
In 2019, 68 corn silage hybrids representing 15 commercial brands were evaluated in a joint trial with Michigan State University (MSU). The Ohio location is combined with Michigan's two southern (Zone 1) silage locations. The trials were divided into two maturity groups designated early and full season on the basis of the relative maturity (RM) submitted by the companies with results listed in separate tables. The Ohio test site was located in our Northwest Region at Hoytville (Wood County). The two MSU sites are located in Branch and Lenawee counties, which are on the Ohio/Michigan state line. (Due to erratic final stands, Lenawee results will not be published.) Test results from the two 2019 locations are combined for the trail average. The plots were planted with 4-row Almaco SeedPro 360 plot planters and maintained by each respective state utilizing standard agronomic production practices. The center two rows were harvested using MSU’s New Holland T6.175 tractor which powered a two-row Champion C1200 Kemper forage harvester with a rear mounted Haldrup M-63 Weigh system.
Silage tests were harvested uniformly as close to half milk line as possible. Near- Infrared Spectroscopy (NIRS) analysis was performed by MSU using their current procedures. Silage results present the percent dry matter of each hybrid plus green weight and dry weight as tons per acre. Other data presented include percent stand, the percentage of in vitro digestible dry matter, acid detergent fiber, neutral detergent fiber, neutral detergent fiber digestibility, crude protein and starch. Milk production in pounds per ton and pounds per acre were estimated using MILK2006 (UW-Madison Dairy Science Department).
A complete summary of the Ohio results are available online at: http://www.oardc.ohio-state.edu/silagetrials. More information on procedures and additional 2018 MSU silage test data can be viewed online at: http://www.varietytrials.msu.edu/corn. For more information on Ohio State crop variety testing, visit: http://u.osu.edu/perf. -
Managing Stored Grain – 2019 Considerations
The Ohio State University Extension will host a webinar featuring Dr. Ken Hellevang, North Dakota State University, to help farmers understand potential concerns with grain storage. This webinar will cover special areas of concern with high moisture grain and excessive fines. The webinar is scheduled for Friday, December 20, 2019 at 3:00 PM. It is free to participate but registration is required. Please register at go.osu.edu/StoredGrain.
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Small Grains Management Workshop
Join OSU Extension as we present a hands-on, intensive small grains management workshop for Ohio crop producers. This workshop will help you become a more profitable small grain producer and will feature a range of winter wheat and barley management topics including: cultural practices, insect and disease management, and soil fertility.
The workshop will be held in three locations from 9:00 AM-2:30 PM:
- Auglaize County on Thursday, January 9 (https://auglaize.osu.edu/events/small-grains-management-workshop)
- Wood County on Tuesday, January 14 (https://wood.osu.edu/news/small-grain-management-workshop)
- Pickaway County on Wednesday, January 15 (https://pickaway.osu.edu/events/small-grains-management-workshop)
Only $10 per person! And each participant will receive a copy of the Ohio Agronomy Guide, Corn, Soybean, Wheat, and Alfalfa Field Guide, Management of Winter Malting Barley guide, and the Weed Control Guide.
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2020 West Ohio Agronomy Day
The 2020 West Ohio Agronomy Day will be held on Monday, January 13th at St. Michael’s Hall in Fort Loramie. Doors open starting at 7:30 a.m. with a marketing update from Ben Brown and The Anderson’s at 8:00 a.m. At 8:30 a.m. the program including Private Pesticide Applicator Recertification (Core and Categories 1, 2, and 6) and the one-hour Fertilizer Applicator Recertification Training for those who are already certified to apply commercial fertilizers will begin. In addition, Certified Crop Adviser CEUs (NM, SW, IPM, CM, and S) and Commercial Pesticide Applicator Credits (Core, 2A, and 2C) have been approved. The program will conclude at 4 p.m.
Purdue’s Dr. Bob Nielsen will be there, this time to talk about “Advancing Corn Production in Ohio.” Also presenting will be Dr. John Fulton, OSU Precision Agriculture, assisted by Elizabeth Hawkins on “Using precision agriculture to improve nutrient and pesticide application,” Dr Laura Lindsey and Dr Anne Dorrance on “How do I get my soybean yields through the glass ceiling?” and Dr. Jeff Stachler, OSU Extension Educator addressing “Weed Control - What we learned in 2019.” Greg LaBarge and Terry Mescher will speak on “Water Quality – Where are we today?” and “How you can make manure work for you in your farming operation?’ will be presented by Glen Arnold.
You can find a copy of the “tentative” schedule for the event at www.shelby.osu.edu. The registration fee varies based on credits needed: $30 for the Private or Commercial Pesticide Applicator recertification, $10 for the Fertilizer Applicator recertification, $10 for CCAs and for those coming just for the Fun, Food, Fellowship, and Lots of Information!! Contact the Shelby County Extension office at 937.498.7239 or email Matt Schmerge at schmerge.1@osu.edu to make your reservation.
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.