C.O.R.N. Newsletter: 2017-10
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Getting corn off to a good start - planting depth can make a difference
Planting depth recommendations for Ohio are 1.5 to 2 inches deep to ensure adequate moisture uptake and seed-soil contact. Deeper planting may be recommended as the season progresses and soils become warmer and drier, however planting shallower than 1.5 inches is generally not recommended at any planting date or in any soil type. When corn is planted 1.5 to 2 inches deep, the nodal roots will develop about 0.75 inches below the soil surface. However, at planting depths less than 1 inch, the nodal roots develop at or just below the soil surface. Excessively shallow planting can cause slow, uneven emergence due to soil moisture variation, and rootless corn (“floppy corn syndrome”) later in the season when hot, dry weather inhibits nodal root development (Nielsen, 2010). According to some field agronomists, shallow plantings increase stress and result in less developed roots, smaller stalk diameters, smaller ears and reduced yields. In a recent OSU evaluation of planting depths, grain yields were about 14% greater for the 1.5-inch and 3-inch planting depths than the 0.5-inch planting depth in 2011, and 40% greater in 2012. The lower yields of the shallow planting were associated with a reduced final stands and 6 to 7 times as many “runt” plants as the other two planting depths.
In a 2013-2014 Cornell University study comparing planting depth across a range of soil types and plant populations, Cox and Cherney (2015) concluded that optimum seeding depth differed across sites and at times across years within sites. Additionally, the risks of reduced population or grain yield were generally greater at the shallow seeding depth compared with the deeper depth (2.5 inches). Research at Kansas State University (Roozeboom, 2012) that evaluated six planting depths ranging from 1 to 3.5 in. supported planting depth recommendations of 1.5 to 2.5 inches depending on soil conditions
Despite potential risks, many growers continue to plant at depths less than 1.5 inches. There is a perception that seed planted shallower than 1.5 in. will emerge more rapidly due to warmer soil temperatures closer to the surface. This is an important consideration as corn growers across the Corn Belt are planting earlier (Kucharik, 2006) so they can complete planting before yield potential begins to decrease after the first week of May. Particularly in soils that crust, speed of emergence is critical in order to establish plant stands before heavy rainfalls “seal” the soil surface.
Recent work by Deere & Company and the University of Illinois (Armstrong et al., 2016) suggests variable seeding depth planting within fields may improve corn yield especially when soil moisture conditions become less ideal (drier or wetter). Research is underway to improve our understanding of corn response to planting depth across different soil types and conditions. Results of this work may enable more effective use of planting technologies that allow variable planting depths during the planting operation.
Literature Cited:
Armstrong, K.L., E.G. Coronel, S.G. Gray, T. G. Mueller, L. L. Hendrickson, and G. A. Bollero. 2016.
Evaluating equipment performance at the row and plant levels. International Annual Meeting. ASA-CSSA-SSSA. Madison, WI.
Cox, W.J. and J.H. Cherney. 2015. Field-scale studies show site-specific corn population and yield responses to seeding depths. Agron. J. 107: 2475-2481.
Kucharik, C.K. 2006. A multidecadal trend of earlier corn planting in the central USA. Agron. J. 98:1544–1550.
Nielsen, R.L. 2010. “Rootless” or “floppy” corn syndrome. Corny News Network, Purdue Extension. [On-line] at URL: https://www.agry.purdue.edu/ext/corn/news/timeless/floppycorn.html (verified 4/24/17)
Roozeboom, Kraig. 2012. Seeding depth of corn. K-state extension. Agronomy e-update. No.333. Jan. 20, 2012.
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Wheat Growth Stages and Associated Management: Feekes 7, 8, and 9
Feekes 7.0: Second Node Becomes Visible
This stage is characterized by the rapid expansion of the head and the presence of two nodes. One node should be between 1.5 to 3 inches from the base of the stem and the other should be about 4 to 6 inches above the base of the stem. These nodes are usually seen as clearly swollen areas of a distinctly different (darker) shade of green than the rest of the stem. Note: the upper node may be hidden by the leaf sheath – you may have to run your fingers along the stem feel it: if only one node is present, then your wheat is still at Feekes growth stage 6. Wheat will still respond to N applied at this time if weather has prevented an earlier application; however, mechanical damage may occur from applicator equipment. Feekes 7 and 8 identification video: https://www.youtube.com/watch?v=PZ7Lvsux1y8
Feekes 8.0: Flag Leaf Visible, but Still Rolled Up
This growth stage begins when the last leaf (flag leaf) begins to emerge from the whorl. This stage is particularly significant because the flag leaf makes up approximately 75 percent of the effective leaf area photosynthesis that contributes to grain fill. It is therefore important to protect and maintain this leaf heathy (free of disease and insect damage) before and during grain development. When the flag leaf emerges, three nodes are visible above the soil surface. To confirm that the leaf emerging is the flag leaf, split the leaf sheath above the highest node. If the head and no additional leaves are found inside, Stage 8.0 is confirmed, and the grower should decide whether or not to use foliar fungicides to manage foliar fungal diseases. This decision should be based upon the following considerations:
- Is a fungal disease present in the field?
- Is the variety susceptible or are weather conditions favorable (wet and humid) for rapid spread and development of the disease(s) found in the field?
- Does the crop yield potential warrant the cost of application of the fungicide in question to protect it?
- Is the crop under stress?
If a positive answer applies to the first three questions, and a negative response to the last, plans should be made to protect the crop from further damage. Check product labels and apply as soon as possible. In most situations, the greatest return to applied foliar fungicides comes from application at Feekes Stages 8-10. Nitrogen applications at or after Feekes 8.0 should only be applied if earlier applications were not made or if N losses may be large from excessive wet conditions. Late N applications may increase protein content but this is not important for yield or milling traits of soft wheats. Moreover, additional N may increase the severity of some foliar diseases, particularly the rusts, and damage from ground application equipment may lower yields.
Feekes 9.0: Ligule of Flag Leaf Visible
Stage 9.0 begins when the flag leaf is fully emerged, determined by a visible ligule. At this time, there will be four visible leaves along the stem including the flag leaf and the lower leaves are referred to in relation to the flag leaf (i.e., the first leaf below the flag leaf is the F-1, the second leaf below is the F-2, and so forth). After flag leaf emergence, yields may be reduced if heavy army worm infestations remove the upper leaves during early grain fill. Feekes 9 and 10 identification video: https://www.youtube.com/watch?v=OHGhq0qSM1o
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BIG SWINGS IN WEATHER PATTERN AHEAD
April will end warmer and wetter than normal. A series of storms will impact Ohio and surrounding areas later this week into next week. This will mean wetter than normal conditions into the first week of May. Temperatures will remain above normal as well. Rainfall on the attached graphic shows the heaviest will fall in central sections of the corn and soybean belt. Rainfall in Ohio will range from 2-4 inches for the next 2 weeks with heaviest totals in western areas of Ohio. Normal is about 2 inches.
The first week of May will be mild with wetter than normal weather. The middle of May will dry out and cool down before a warm finish to the month.
The outlook for summer still looks warmer than normal with rainfall highly variable with a tendency toward drier.
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Seeding Recommendations Following Pipeline Construction
Many farms are having pipelines installed as construction continues through a number of counties across the state. Following construction of a pipeline comes the need to seed the area above and adjacent to the pipeline, and there are a number of seeding mixtures available to re-establish vegetative growth. There also are a number of questions that should be answered prior to making a seeding. These questions include:
- What grasses and forages were present prior to seeding?
- What will you do with the land following construction?
- Will you graze livestock on the land?
- Do you prefer a pure seeding mixture?
Below is a link to an Ohio State University Extension Fact Sheet that will assist in answering these questions. This publication also addresses seeding options and rates.
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Cooperators Needed for Pipeline Impacts Study
The Ohio State University is conducting a study to better understand and manage the impacts of pipeline installations across the state. We are looking for interested farmers who will have the Utopia Pipeline installed through their farm in Wayne, Ashland, Richland, Huron, Seneca, Stark or Tuscarawas Counties. We will evaluate crop yields and soil properties over the installed pipeline and in an unaffected adjacent area, using yield maps, aerial imagery, and soil analyses. We are primarily interested in grain crops, but will also work with a limited number of hay fields. For more information or to sign up visit: go.osu.edu/pipeline
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Pasture Walk to Evaluate Forages
A farm near Ridgeway, Ohio will serve as the location for the Hardin County Pasture Walk on Wednesday, May 3. This program will be from 6:00-7:30 pm in a pasture located at 18917 County Road 155, Ridgeway, OH 43345. A pasture walk is an educational program for producers who would like to learn how to best manage forages in their pastures and evaluate best management practices for grazing.
Megan Burgess of the Hardin County Natural Resources Conservation Service (NRCS) will be the main instructor along with Gary Wilson, retired Extension Educator from Hancock County. Both Burgess and Wilson have served on the Ohio Forage and Grassland Council. Topics presented at the pasture walk will include but are not limited to evaluating your resources, forage species, establishing and maintaining pastures, using a grazing stick to estimate dry matter, as well as other topics that come up from the participants present at this program.
Each operation attending will receive a grazing stick as well as university fact sheets on various pasture related topics and issues. Water and light refreshments will be served. Those planning to attend the Pasture Walk program are asked to call the Hardin County Extension Office at 419-674-2297 or email badertscher.4@osu.edu so that plans can be made for an informative evening.
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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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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