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Ohio State University Extension

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C.O.R.N. Newsletter: 2015-20

  1. Scabby wheat grain? Increasing your Fan Speed May Help

    Author(s): Pierce Paul

    Wheat harvest in now in progress and will continue over the next several days before and after the next showers. Early reports on grain quality indicate that a few fields may have moderate levels of scabby grain, and consequently could have vomitoxin contamination above thresholds set by grain buyers. The threshold set by the US Food and Drug Administration for harvested grain intended for animal and human consumption is 2 ppm, but elevators may accept grain with slightly higher levels, depending on how big of a problem we have and whether or not they can find clean grain to blend. Although head scab was not widespread across the state this year, there were a few small pockets with 10 to 15% scab incidence (10 to 15 out of every 100 heads with some amount of scab). These will likely be the fields with the biggest grain quality and vomitoxin problems. In addition, the rains we have had over the last few weeks may have contributed to making the situation worst, increasing scabby grain and vomitoxin levels and reducing test weight beyond what you would expect based on the observed levels of scab.

    Remember, scab causes kernels in affected heads to become small, shriveled, lightweight, discolored (whitish and pinkish), and contaminated with vomitoxin (and other mycotoxins). So, in general, the more scab you have, the more damaged kernels you will see in your grain lot, and high levels of damaged kernels are often associated with high levels of vomitoxin contamination. However, scab is not the only thing that reduces grain quality. Other late season diseases such as Stagonospora and well as poor weather conditions in the weeks leading up to harvest may also cause kernels to become shriveled and lightweight. So before you start worrying about vomitoxin or even thinking about abandoning your crop, examine your grain lot for the presence of chalky-white, pinkish kernels; this would be a good way to tell whether you have a grain quality problem and whether it is due to scab or some other factor.

    Before you being to harvest, collect and thresh multiple heads (two to three handfuls) from multiple locations across your field and examine the grain for discoloration. If you see a lot of small, shriveled, discolored kernels, you should consider increasing your fan speed during harvest to blow them out. Research in the cereal pathology lab at OSU/OARDC showed that when harvesting wheat from scabby fields, increasing the fan speed and air flow through the combine can reduce the amount of scabby kernels and vomitoxin in the grain lot by an average 30 to 45%, and increase test weight by about 6%. This could reduce price discounts by up to 50%, depending on how badly damaged the grain is. However, there is a limit to which you could increase the fan speed without blowing out healthy kernels, so unless you have to, do not increase the fan speed beyond the default wheat setting of your combine. Usually, if you have less than 5% scabby kernels in your sample, you will not see a major benefit from increasing the fan speed.

    Harvest suspect fields separately from healthy fields, and make sure you dry the grain down to below 15% moisture before storage. Store dried grain at cool temperatures (35-45F). This will reduce the risk of further mold growth and mycotoxin problems in storage.     

  2. Good Time to Dig Roots and Inspect for Rootworm Damage

    Author(s): Andy Michel

    The good news with all the rain is that it likely caused substantial mortality in corn rootworm larvae. However, growers should still be mindful of our most important corn insect. Over the next few weeks is the time that growers should dig corn roots and inspect them for rootworm feeding.  Dig at least 5 plants in 10 different locations in your field.  To determine the level of injury, use the Node Injury Scale—this scale ranges from 1 to 3, were 0.5 is half of a node of roots damaged, 1 is a full node of roots damaged, 2 is 2 full nodes damage, etc. For more help in rating roots, see this handout from Michigan State:http://www.msuent.com/assets/pdf/42CRWRating.pdf. Economic damage occurs from anywhere starting at 0.25 and above, depending on weather conditions—usually any ratings above 0.75 indicates substantial damage. See our fact sheet for more information: http://ohioline.osu.edu/ent-fact/pdf/ENT_16_14.pdf  

    Growers should also keep in mind the risk of Bt resistance.  Although we have not had any official cases of Bt resistance, observations from the Western corn belt suggest fields with corn for more than 3 straight years is at high risk for developing resistance.  Any rating more than 1.0 in corn fields containing Cry3b1, or any rootworm trait for that matter,  might suggest potential resistance (remember, if you are using a blended refuge and find a damage root, use Bt test strips to make sure you have inspected a Bt plant).  Based on the pattern in the western corn belt, continuous corn fields for more than 3 years should be our first priority.  If you suspect any cases of resistance please contact state entomology specialist (michel.70@osu.edu) or your local extension educator.

     

    NOTE:  The link to the Michigan State handout has been updated since the original version of this issue of the CORN Newsletter was published/sent.

  3. Foliar Diseases Already Showing up in Corn

    Gray Leaf Spot on Corn
    Author(s): Pierce Paul

    Foliar diseases, especially Gray Leaf Spot (GLS) and Northern Corn Leaf Blight (NCLB), are already showing up in some corn fields. Although this a little bit on the early side for Ohio, it is not at all surprising, since we have had several wet, humid days over the past few weeks, with moderate to warm temperatures. Both GLS and NCLB are favored by wet conditions, particularly if temperatures are within the favorable range like they have been (70 to 90 F for GLS and 66 to 80 F for NCLB).

     Northern Corn Leaf Blight

    Foliar diseases of corn are generally a concern when they develop early and progress up the plant before grain fill is complete. This is especially true when the hybrid is susceptible. In most years, GLS and NCLB usually develops late and has very little or no effect on the crop. If it continues to rain and stays humid, this will likely not be the case in some fields this year. We are already seeing typical, well-developed lesions on the plant well before tassel (VT) in some fields.

    Because of the wide variation in planting dates and weather conditions this year, the corn crop is at growth stages ranging from about V10 (ten-leaf stage) to VT across the state. With such a wide variation in crop development, if the weather continues to be favorable for disease development, some fields and some hybrids could certainly be infected early and could suffer yield reduction if not treated.

    Continue to scout fields for foliar diseases, especially those planted with susceptible hybrids in an area with a history of gray leaf spot or northern corn leaf blight or in a continuous-corn, no-till field. These fields are the ones most likely to benefit from a fungicide application. Use hybrid susceptibility, weather conditions, field history, and current disease level as a guide when making a decision to apply a fungicide. There are several very good fungicides to choose from. Follow the labels and keep your eyes on the fungicide price and application cost when making a decision. Use the information below as a guide when making your fungicide application decision:

    ·         Susceptible hybrids:  If disease symptoms are present on the third leaf below the ear or higher on 50% of the plants examined.

    ·         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.

    ·         Resistant hybrids:  Fungicide applications generally are not recommended.

  4. Western Bean Cutworm Flight Has Begun

    Western Bean Cutworm Damage on Corn
    Author(s): Andy Michel

    Our trapping network has started to catch western bean cutworm (WBC) adults, meaning that flight is underway. WBC emergence occurs, for the most part, during July, although it can be extended into August, so we expect our counts to increase. Females lay eggs on corn, and, after hatch, the larvae feed on the tassel, pollen or silk before entering the ear.  Late season damage can be quite substantial, as shown in the figure.

    From our previous seasons, we have not seen tremendous damage from WBC.  Most adults are caught north of US-30, which is about the upper 25% of OH. Additionally, damage reports have centered on extreme northwest and northeast OH, but only a few fields have had economic damage.  The extreme rainfalls in June have led to poor or delayed corn development in some areas, or perhaps replants.  Females prefer to lay eggs in pre-tassel corn, so any corn that has not tasseled by the 3rd or 4th week of July (which is usually peak flight) is at high risk for WBC infestation.    

    The best way to control WBC is to scout corn for the presence of egg masses.  Egg masses appear in clumps of 25-100, and are first white, then turn purple within 24 hours of hatching. Inspect 20 plants in 5 locations—if 5-8% of the corn has an egg mass, then treatment might be necessary. Bt corn can be a good option, but only varieties with the Cry1F gene or Vip3A will offer control against WBC. See our fact sheet (http://ohioline.osu.edu/ent-fact/pdf/ENT_40_14.pdf) for more information. 

  5. When Is It Too Late to Fertilize Corn with Nitrogen?

    Heavy rainfall over the past several weeks has left many producers across the state with few opportunities to side dress their corn with nitrogen. To make matters worse, excessive water means that significant soil nitrogen has likely been lost through denitrification and/or leaching. It’s not uncommon or surprising to see standing corn crops with severe yellowing, indicating some level of nitrogen deficiency. Most of the corn in the state has grown too tall for standard application equipment to pass over without crop damage, and some corn is entering late vegetative stages. Given all this, when is it too late to fertilize corn with nitrogen?

    Numerous studies have shown that late season nitrogen rescue applications often pay off. Studies from the University of Missouri and elsewhere have shown that broadcast applications of urea or dribbling on 28% UAN are effective strategies for providing corn with late season nitrogen. Some leaf burn may occur with broadcast urea, but this translates into very little yield loss, if any.

    But how late is too late? Trials applying nitrogen as late as tasseling show that this can still be very effective, but after tasseling application has yielded mixed results. Nitrogen uptake slows considerably after tasseling, as the plant shifts focus from soil nitrogen uptake through roots, to translocation of stored nitrogen in vegetative parts into grain.

    And what about the rate? If no nitrogen has been applied via side dress, full or nearly full nitrogen rates are recommended. Although it is difficult to determine how much soil nitrogen is lost with wet conditions, additional nitrogen may be applied to counter the losses in those extremely wet conditions.

     

    References:

    http://plantsci.missouri.edu/nutrientmanagement/nitrogen/loss.htm

    http://corn.osu.edu/newsletters/2010/2010-17/late-applications-of-nitrogen-to-corn

    https://www.agry.purdue.edu/ext/soilfertility/news/Late-seasonnitrogen.pdf

  6. Cover Crops for Prevented Acres

    Submitted by Allan Sundermeier.


    Excessive rainfall and prolonged ponding conditions this spring have resulted in many fields remaining unplanted to corn or soybeans this season. These “prevented planting” acres, while unfortunate for this year’s production, should be managed in ways to prevent further soil degradation and to increase soil productivity for next year. Cover crops are an excellent option for producers to consider for protecting their soil and increasing productive capacity for succeeding years. This article from Purdue University briefly describes the benefits of growing cover crops compared to leaving the soil bare and fallow, and then it provides guidance on selecting and seeding cover crops for prevented planting acres: https://ag.purdue.edu/agry/extension/Documents/PreventedPlantingCovers2015.pdf



    Choose your cover crops, seeding dates and rates, with the following tools:

     
    Midwest Cover Crops Council Decision Tool,http://www.mccc.msu.edu/selectorINTRO.html  (Choose cover crops for your particular goals, planting dates for your county)

    Indiana NRCS Cover Crops Seeding Calculator, calculate seeding rates for each species in a mix:           
     http://efotg.sc.egov.usda.gov/references/public/IN/IN_NRCS_Cover_Crops_Seeding_Calculator.xlsm
     
    Additional Resources
    • Midwest Cover Crops Council:  http://www.mccc.msu.edu
     •Midwest Cover Crops Field Guide, 2nd ed. Available from Education Store, Purdue Extension.
    • Herbicide carryover:   A good Extension publication from Penn State that fits Indiana is:  http://extension.psu.edu/plants/crops/soil-management/cover-crops/herbicide-persistence/herbicide-carryover-table
    © 2015, Purdue University
  7. Ohio Fertilizer and Manure Application-New Legislative Criteria

    New regulations for manure and fertilizer application started on July 3, 2015 when Senate Bill Number 1 came into effect. The legislation affects nitrogen and phosphorus application whether applied as manure or granular fertilizers. Parts of the regulations are targeted specifically to define watersheds that encompass the Western Basin of Lake Erie while one provision is effective statewide. The text below summarizes important provisions but does not substitute for the legislative text which is found in Ohio revised code sections 6109.10, 903.40, 905.326, 905.327, 1511.10, 1511.11, 3745.50 and 6111.32 plus subsequent rule making by the state agencies. These rules are in addition to the Agricultural Fertilizer Applicator Certification program which began in September, 2014.

    Figure 1. Watersheds and Associated Counties Named in SB 1 (in Yellow)

     

     

     

     

     

     

     

     

     

    Fertilizer application restrictions (in the western basin only)

    (Administered through Ohio Department of Agriculture (ODA))

    For applications of fertilizer in the western basin, a person may not apply fertilizer, defined as nitrogen or phosphorous, under these conditions:

    (1)    On snow-covered or frozen soil, or

    (2)    When the top two inches of soil are saturated from precipitation, or

    (3)    In a granular form when the local weather forecast for the application area contains greater than a 50% chance of precipitation exceeding one inch in a twelve-hour period,

    unless the fertilizer is injected into the ground, incorporated within 24 hours of surface application or applied onto a growing crop.

    Manure application restrictions (in the western basin only)

    (Administered through Ohio Department of Natural Resources till 12/31/2015 then ODA)

    A person may not surface apply manure in the western basin under any of the following circumstances:

    (1)    On snow-covered or frozen soil;

    (2)    When the top two inches of soil are saturated from precipitation;

    (3)    When the local weather forecast for the application area contains greater than a 50% chance of precipitation exceeding one-half inch in a 24 hour period.

    unless the manure is injected into the ground, incorporated within 24 hours of surface application, applied onto a growing crop, or if in the event of an emergency, the chief of the division of soil and water resources or the chief's designee provides written consent and the manure application is made in accordance with procedures established in the United States department of agriculture natural resources conservation service practice standard code 590 prepared for this state.

    Facilities currently permitted as Confined Animal Feeding Operations (CAFO) and Certified Livestock Managers (CLM) must continue to follow more restrictive criteria based on soil hydrologic classification noted in the facility permit.

    Exemption request process for small and medium operations. 

    Small and medium agricultural operations may apply for a temporary exemption from the law’s restrictions on manure applications.  Size of operation is defined in Ohio Revised Code (ORC) and is summarized in Table 2. The chief of the division of soil and water resources may grant an exemption of up to one year for a medium agricultural operation and up to two years for a small operation, if the operation is working toward compliance.  An exempted operation may request technical assistance to reach compliance, and will not be subject to civil penalties for violations.  The law defines small and medium agricultural operations in the same way as the Livestock Environmental Permitting program, based on the number of livestock according to species. 

    Complaints and Penalties

     

     

     

    The trigger for an investigation is a complaint by any person or information received by the state authority that a violation has occurred. Both the Fertilizer and Manure rules give the appropriate state authority the ability to assess civil penalties that shall not exceed $10,000 per violation. The right to a hearing and other administrative procedures are defined.

     

     

    Certification requirements for persons using manure from Confined Animal Feeding Operations (CAFFs)(Applies statewide) 

    To utilize manure from a concentrated animal feeding facility that is regulated under ODA’s Division of Livestock Environmental Permitting, a person must either hold a Certified Livestock Manager license or be certified under Ohio’s Agricultural Fertilizer Applicator Certification program.  The provision pertains only if applying the manure for agricultural production on more than 50 acres.  

     

     

    Obtaining Precipitation Information to Meet 12 and 24 Hour Forecast Criteria

    New Ohio regulations in targeted watersheds in the Western Lake Erie Basin require considering ground conditions and predicted rainfall prior to granular fertilizer and manure applications started on 7/3/2015. For granular fertilizer, applications should not occur when the local forecast contains greater than a 50% chance of precipitation exceeding one inch in a twelve-hour period. For manure, application should not occur when the local forecast contains greater than a 50% chance of precipitation exceeding one-half inch in a 24 hour period. It is recommended that forecast information be printed off prior to planned applications. This provides the applicator proof of reviewing the forecast if actual rainfall exceeds the predicted rainfall.

    A good source of a printable local forecast can be obtained from NOAA through the website http://weather.gov. A zip code location close to the application site can be entered on the website. A detailed hourly forecast graphic can be reviewed and printed off as seen in Figure 2. Rainfall can be totaled from the graphic to obtain the needed 12 or 24 hour predicated rainfall. A short video presentation showing how to obtain the forecast can be found on the OSU Agronomic Crops Team You Tube Channel at https://www.youtube.com/watch?v=Z7Ip8hsL4bA

    Figure 2. Example of Detailed Hourly Forecast from NOAA that can be used meet granular fertilizer and manure application criteria.

  8. Ohio Long-Term Phosphorus and Potassium Fertilizer Trials: Grain Yields

    Author(s): Eric Richer, CCA

    Additional Authors:  Anthony Fulford, Clay Dygert,

    Ohio corn, soybean and wheat check-off dollars are currently funding Ohio State Extension research to update the Tri-State Fertilizer Recommendations for Corn, Soybeans, Wheat and Alfalfa (http://ohioline.osu.edu/e2567/index.html). As part of this effort, this is the first of several articles on the results of a nine-year corn and soybean trial conducted in Clark, Wayne, and Wood counties. The main goal of the study was to evaluate grain yield response to phosphorus and potassium fertilization. Corn and soybean were grown in 2 rotations (corn-soybean and corn-corn-soybean) for 9 years (2006–2014) at 3 sites for a total of 54 site-years. At each site and in each rotation, there were 3 rates of phosphorus (0, 1x, 2x) and 3 rates of potassium (0, 1x, 2x). Fertilizer rates for each rotation were determined by the estimated nutrient removal rates of corn and soybean grain at harvest. In other words, 1x represents nutrient removal rates with average yields and 2x represents the estimated nutrient removal when average yields are doubled.

    At the start of the study in 2006, soil test phosphorus levels were within or above the maintenance range (15–30 ppm Bray P) at all three sites (27 ppm at Clark County; 37 ppm Wayne County; 30 ppm at Wood County). Likewise in 2006, soil test potassium levels were within or above the maintenance range (100–155 ppm ammonium acetate K) at all three sites (115 ppm at Clark County; 133 ppm Wayne County; 209 ppm at Wood County).

    Corn and soybean grain yield responded positively to phosphorus and potassium fertilization in 14 of the 54 yield trials conducted from 2006 to 2014. A positive yield response to phosphorus fertilization was documented in 18% of corn trials and 5% of soybean trials. A positive yield response to potassium fertilization occurred in 9% of corn trials and in 19% of soybean trials.

    Trends were examined to see if a lack of fertilization became more pronounced over time. There was a clear relationship between phosphorus and years since fertilization, but no clear relationship between potassium and time (Table 1).

    Table 1. Number of occurrences that corn or soybean grain yields increased with fertilization.

    Nutrient

    Early (2006-2008)

    Mid (2009-2011)

    Late (2012-2014)

    Total (2006-2014)

    Phosphorus

    0 out of 18

    2 out of 18

    5 out of 18

    7 out of 54

    Potassium

    3 out of 18

    3 out of 18

    1 out of 18

    7 out of 54

     

     

     

     

     The general lack of positive fertilizer responses suggests that the Tri-State recommended maintenance range for soil test phosphorus and potassium values are still relevant at these three sites, although some modifications may be necessary as we continue to collect more data. On-farm fertilizer response trials are currently being conducted across the state to evaluate these maintenance ranges for sites with different management histories. These on-farm trials will complement the information shown here. Farmers, crop consultants and agronomists interested in contributing to this state-wide project are encouraged to contact Steve Culman at culman.2@osu.edu.

     

    Reference: Vitosh, M.L., J.W. Johnson, and D.B. Mengel. 1995. Tri-State Fertilizer Recommendations for Corn, Soybeans, Wheat and Alfalfa. Ext. Bull. E-2567. Available online at: http://ohioline.osu.edu/e2567/index.html

  9. OSU Extension to Hold NW Ohio Precision Ag Day and “Fert-Cert” August 4th

    Farmers and crop consultants interested in seeing the latest nutrient application equipment for corn, soybeans and wheat are encouraged to attend the Tuesday, August 4th Northwest Ohio Precision Ag Technology Day at Fulton Co Fairgrounds in Wauseon.  This year’s field operation of interest is precision nutrient management. The event will qualify as a full, 3 hour “fert-cert” to comply with Ohio Senate Bill 150 regulations.  The event will also offer at least 4 hours of Certified Crop Advisor credits, including Soil/Water and Nutrient Management.

    In the morning, producers will hear sessions on phosphorus management with Dr. Steve Culman, the new OSU Extension Soil Fertility Specialist, nitrogen timing and placement strategies with Dr. John Fulton, the new OSUE Precision Ag Specialist and a session on nitrogen rate and source considerations by Eric Richer, OSUE Fulton County.  The morning will wrap up with a panel discussion by retailers and service providers who are using nitrogen management models.  Again, the 8:30 am to lunch sessions will qualify as a “fert-cert” for those with or without a pesticide license.

    In the afternoon, there will be live nutrient management demonstrations from Case IH (Archbold Equipment), John Deere (Kenn-Feld Group), Salford/Yetter (Paul Martin & Sons), Unverferth and Orthman Strip Tiller (Greenfield Ag).  Demonstration will focus exclusively on nutrient placement and timing. 

    This event is from 8 am to 3:30 pm and open to the public.  Registration is $25 prior to July 31st or on site for $40. For a complete agenda and registration form, seewww.fulton.osu.edu. Credit card payment is available online athttp://pested.osu.edu/NutrientEducation/training-NW.html. The Fulton County Fairgrounds are located at 8591 State Route 108, Wauseon, OH 43567. Questions related to this program can be directed to richer.5@osu.edu or call the Fulton County OSU Extension office at 419-337-9210.

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

Amanda Bennett (Educator, Agriculture and Natural Resources)
Ed Lentz, CCA (Educator, Agriculture and Natural Resources)
Glen Arnold, CCA (Field Specialist, Manure Nutrient Management )
Greg LaBarge, CPAg/CCA (Field Specialist, Agronomic Systems)
Jason Hartschuh, CCA (Field Specialist, Dairy & Precision Livestock)
Les Ober, CCA (Educator, Agriculture and Natural Resources)
Mark Badertscher (Educator, Agriculture and Natural Resources)
Mike Gastier, CCA (Educator, Agriculture and Natural Resources)
Sam Custer (Educator, Agriculture and Natural Resources)
Sarah Noggle (Educator, Agriculture and Natural Resources)

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.

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