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Agronomic Crops Network

Ohio State University Extension


C.O.R.N. Newsletter 2012-04

Dates Covered: 
February 20, 2012 - March 6, 2012
Harold Watters

Late February Weather Outlook


A weak La Nina (cooler equatorial Pacific Ocean waters) is ongoing this winter. However, last winter we had a moderate to strong La Nina event. The stronger the event the greater the impact on our weather here. The tendency is for wetter conditions during La Nina events for winter and spring. However, the weaker the event then the more likely other factors will impact our weather. This is the case this winter. This winter we have had a positive North Atlantic Oscillation while last winter we had a negative North Atlantic Oscillation (NAO) . The NAO is is the relationship between the Greenland/Iceland low pressure and the Azores high pressure. Ocean temperatures are also a part of the equation. In the negative phase, it tends to be colder and snowier. In the positive phase, it tends to be warmer and wetter here for winter and early spring. NAO is having an influence on our weather pattern along with many other factors but given the weaker La Nina this winter it argues for a great chance that 2012 will be different than 2011.

Two week outlook:

The weather pattern looks to become more active with a series of storms the next 2 weeks. Expect temperatures to be close to normal with precipitation above normal, mostly rain with a little snow expected. 

March outlook:

Expect the overall pattern from winter to continue with warmer and wetter conditions.

Longer-term outlook:

La Nina is forecast to end in the spring. If NAO continues to be positive it will favor a trend of warmer than normal weather with the wet March transitioning to normal or even below normal rainfall by May. The official outlook for summer is equal chances for temperatures and rainfall but if La Nina ends and we keep a positive NAO it will favor close to normal temperatures with some periods of dry weather.


The outlook favors more of the same into March with warmer and wetter conditions dominating with limited snow events. Changes may occur after that though.

Nitrogen Management for Late Planted Wheat


Because of the wet fall and delayed planting wheat has had little time to tiller and grow this season. In some situations, producers were unable to apply starter N to the crop before planting. The general recommendation is to apply N one time between greenup and early stem elongation. However, producers have asked would applying N earlier offset the low fall tiller numbers (increase spring tiller numbers) and would tiller number and growth benefit from a split application?

Some points to remember as we determine a management plan:

1)    Wheat requires very little N until early stem elongation. Seldom is N the limiting factor for fall growth and tillering. Even if N was not applied this fall, in most years organic matter in the soil is adequate to release enough N for early spring growth. We general recommend 20 – 30 pounds of N in the fall as insurance since we are planting no-till. However, where we have included fall treatments in N studies we have not seen a yield benefit. Another factor to consider this year, available soil N is more abundant with moderate winter temperatures, such as those we have experienced this winter.

2)    Tillers that appear in the fall are responsible for most of the yield in the crop. Spring emerging tillers that develop into a spike generally are much smaller than fall tillers. From my observations, deficient levels of N for the growing season affect number of spikelets per head more than spikes per plant. However, vegetative tiller numbers may be increased with earlier N (we have not taken this measurement) but it has not affected yield.

With these points in mind, there is no reason to change management strategies. Spring N should be applied between greenup and early stem elongation. However, applying N before greenup should be avoided. Research data has shown that N applied prior to greenup, regardless of form may be lost and yields greatly reduced. Urea, urea-ammonium nitrate (28%) and ammonium sulfate were included in these studies. In most years, greenup does not occur until March 10 – 15 and in some years as late as April 1. I have not seen it occur in February anywhere in the state.

Split application of N would be an acceptable management system and may have larger yields compared to a single topdress at initial greenup, depending on the weather. Also a split would be a hedge if weather prevented N to be applied prior to stem elongation. However, research data has shown that a single topdress of N applied at early stem elongation yielded as well or better than a split application and unless large N losses occurred at early greenup, yields were similar between early greenup and split applications.  Also keep in mind that if N losses were great at early greenup, N would also be lost from the first part of a split program. Thus a producer selecting the right time and N source should expect yields similar to a split application -- saving the cost and potential damage of a second trip across the field. 

Nematodes in Corn


Over the last few years, interest in corn nematodes has increased among producers all across the Midwest. When present and in high numbers, these worms that feed on the roots of the corn plant can indeed cause considerable yield loss. However losses due to nematodes often may go undetected or may be attributed to other causes. In corn, nematode problems are usually very difficult to detect because these pathogens usually cause uneven growth, without any clear above-ground symptoms. Uneven growth could be the result of several factors including other soil borne pathogens, poor drainage, soil compaction, and herbicide carry over; nematodes are rarely ever considered the cause of such a problem. Several different types of nematode can attack corn including spiral, lesion, cyst (this is not the soybean cyst), stubby root, needle, lance, and dagger nematodes, and the level of damage and yield loss depend on the type of nematode and the population level. Moreover, it is rare to find a single type of nematode causing damage in any given corn field. Nematodes usually occur as a community comprised of different species and damage is usually the result of a nematode complex made up of several different types of nematodes. In addition, wounds made by nematodes, especially those that enter and feed inside the roots (endoparasites), may serve as entry points for infection by secondary or opportunistic fungi, adding to the overall level of damage.

It is unclear whether we do indeed have a nematode problem in corn in Ohio and if seed treatment nematicides are needed. As stated above, the impact of nematodes on corn is very difficult to determine. In Ohio, we have a very good database on the distribution and effects of soybean cyst nematode (SCN), but SCN does not affect corn. We do not have any information on the distribution or effect of nematodes on corn in Ohio. A survey of cornfields is needed to determine which nematode species are present and at what population levels. Such a survey was recently completed in the state of Illinois by Dr. Terry Niblack, extension specialist and nematologist. More than 550 fields were surveyed and nematodes were found in every field, at populations ranging from 100 to 4000+ nematodes per 100 cc of soil. Most of these were plant parasitic nematodes, belonging to more than nine different genera, of which the “tylenchides”, nematodes with small styles and pointy tails, were the most frequent. These were found in 99% of the fields. However it is unclear what these organisms are doing in corn fields, since members of this group include plant parasites as well as parasites of fungi and algae. Of the known “tylenchides” observed, the spiral nematode (Helicotylenchus) was the most frequent. These were found in 99% of the soils, in most cases at moderate- to high-risk population levels (above 150 nematodes per 100 cc of soil). The lesion nematodes (Pratylenchus) were the second most prevalent nematode in Illinois cornfields. These were found in 84% of the fields, at population levels above moderate risk thresholds in more than 50% of the fields in which they were present. Among these was Pratylenchus penetrans, a notoriously damaging species of lesion nematode on other crops such as potato. Greenhouse studies have shown that P. penetrans can also cause severe damage in corn; however, the level of damage caused in cornfields is unclear. The third and fourth most frequently observed nematodes were the stunt and lance nematodes, and these were also found at levels considered above moderate damage thresholds. The pin, ring, dagger, stubby-root, needle, root-knot, and sting were found in localized areas in Illinois, with the needle and sting nematodes found predominantly in sandy soils.

So, can we assume that the corn nematode population in Ohio would the similar or identical to that observed in Illinois? Not really, soil type, crop rotation, and corn hybrids may all influence the distribution and type of nematode communities present in any given area. Surveys are needed to help us determine what we have in Ohio. Even if we find the same set of nematodes, can we assume that they are causing damage to our corn crop? No, studies are needed to determine population levels and damage thresholds under conditions in Ohio. However, even without a survey, several of our current crop management practices favor potential nematode problems. These include our widely used no-till or conservation tillage and corn-on-corn cropping systems and the abandonment of soil applied insecticides which in the past provided the added benefit of controlling nematodes. So, while we wait for resources to conduct field surveys across the state of Ohio, we can use our understanding of the biology of these pathogens to make a projection as to where nematodes are most likely to be a concern and management practices for minimizing losses caused by these organisms. Nematodes are most likely to cause problems in no-till, corn-on-corn fields, and as such crop rotation and tillage would be the best approaches for minimizing such problems (along with other disease problems). However, again, further research is needed in order to provide other management recommendations, such as seed treatments and hybrid resistance or tolerance. The effect of seed treatment nematicides on nematode population is unknown, and trials from other states have shown variable yield responses to these products among locations and hybrids. 

Audience Response from the 2011 Ohio Conservation Tillage Conference


Audience response system technology (RST) was utilized at the 2011 Ohio Conservation Tillage Conference (CTC) to capture farmer/fertilizer dealer/crop consultant corn production practices.  At CTC one large room (where major sessions on crop production were presented) with a seating capacity of 425 was populated with 210 RST devices.  After each session participants were asked up to four questions that related to grower corn production practices and/or their views on issues impacting agriculture. 

RST will again be used at the 2012 CTC, March 6 & 7, to obtain production information, opinions on major issues and adoption/non adoption of various practices.  The information obtained will used to design both future agronomic programs and applied research trails to address the needs identified by CTC participants.

Key finding from 2011 related to corn production include the following: 

CTC Reported Corn Production Practices



Greatest % of Responses

What is the most limiting factor to high corn yield?

Lack of plant available water


Describe the crop rotation that is used on the majority of your corn acres?

Corn/Soybean (2 year rotation)


Describe the corn tillage system that is used on the majority of your corn acres?

Conservation tillage (30% residue after planting)


What is the most limiting factor to adopting strip tillage in your farm?

Time or suitable soil conditions to build strips in the fall


What is the most limiting factor to adoption of no tillage corn on your farm or in your agricultural business?

Cool soils leading to delayed/uneven emergence


What factor would cause you to adopt no tillage corn?

Greater profit per acre


At what corn seeding rate per acre will you plant the majority of your corn in 2011?

32,001 to 34,000



CTC participant views on the most important problem confronting crop farms in 2011 follow:

What are the most important problem confronting crop farmers in 2011?

Land values/land rent


New agricultural regulations


Less opportunity for young to enter production agriculture




Hazardous Algae Blooms


Soil Erosion


CAUV taxes on agricultural farmland



Ohio Weed Resistance Workshops


The OSU Extension Agronomic Crops team, Ohio Soybean Association, and Ohio Agribusiness Association, along with various other entities, are sponsoring workshops on herbicide and weed resistance on Feb 28 and 29, and March 1.  The workshops run from 9 am to noon, and are at the following locations:

Feb 28, Fisher Auditiorium, OARDC, Woster

Feb 29, Fawcett Center, OSU, Columbus

March 1, The Centre, Bluffton

The objective of the workshops are to 1) bring Ohio growers and agribusiness up to date on our current herbicide resistance situation and also the severity of the Palmer amaranth resistance in the cotton belt; and 2) outline our current recommendations on prevention and management of resistance.  The workshops are free to attend, and lunch will be served at the conclusion of the morning program.  For more information and to preregister (required), visit the Ohio Agribusiness Association online at, or by calling 614-326-7520.

Conservation Tillage Conference March 6 and 7 2012


The Conservation Tillage Conference (CTC) will be held at Ohio Northern University on March 6 and 7, 2012.  CTC registration in 2011 was 1024 with participants farming or making recommendations on over 697,000 acres of crops.  Registration has increased 25% over the last 4 years.  The primary reason participants in 2011 attended CTC was to obtain information on corn and soybean production.  Farmers placed a value of $13.00/acre on the information obtained at CTC, while Crop Consultants valued information at $15.00/acre.

On Monday, March 5 an optional Soil Quality Workshop will be held and continued the next day. 

On Tuesday, March 6, Corn University, Tillage, Nutrient Management, Soil Quality, and Cover Crops will be offered in concurrent sessions.

On Wednesday, March 7, Soybean School, Water Quality, Nutrient Management, Decision Agriculture, and Precision Agriculture will be offered in concurrent sessions.

Conference presenters will include Jill Clapperton, Montana State University; Emerson Nafziger, University of Illinois; Bill Wiebold, University of Missouri; Paul Jasa, University of Nebraska; Don Reicosky, USDA-ARS (retired); Jose Moralles, Brazil; Laura Bast, Michigan State University; Greg Roth, and Sjoerd Duiker, Penn State University; Shaun Casteel, Purdue University; Peter Thomison, Mark Loux, Ron Hammond and Anne Dorrance of The Ohio State University – along with Jim Beuerlein, OSU Extension Soybean Specialist (retired); and many other Extension and industry professionals.

 CCA credits will be available with an emphasis on Soil and Water hours (14.5) and Nutrient Management (18).  The Ohio Crop Consultant of the Year will be honored at the end of the general session on Tuesday, March 6. Vendors representing various agricultural businesses will also have displays and will be prepared for discussion.

The full program and registration details are available at  Please call Allen SWCD at 419-223-0040 with any registration questions.


March 2012 Calendar of Agronomic Events


For more information and links – .

March 8

  • Ohio Pesticide Commercial Applicator Recertification Conferences 2012
  • Columbus Convention Center, Columbus, Ohio
  • Recertification opportunity for Ohio Commercial license holders.

March 19

  • Overholt Drainage School-Session 1
  • Baughman Tile Co., Paulding County, Ohio
  • SESSION I: March 19-20 (1 ¾ days) Laser Surveying, Topographic Mapping, & GPS Mapping; Monday 9:00 AM to 9:00 PM Tuesday 8:00 to 4:30 PM

March 20

  • Software for Developing Nutrient Management Plans Workshop
  • Marion County Extension Office, 222 West Center Street, Marion, Ohio 43302
  • For Certified Crop Advisers who would like to become a NRCS Certified Nutrient Management Plan Provider Planner or NRCS/SWCD personnel.

March 20

  • Overholt Drainage School-Session 2
  • Baughman Tile Co., Paulding County, Ohio
  • SESSION 2: March 20-22 (2 1/3 days) Agricultural Subsurface Drainage Design, & Installation Tuesday 6:00 to 9:00 PM; Wednesday 8:00 AM to 9:00 PM; Thursday 8:00 to 9:00 PM

March 22

  • Software for Developing Nutrient Management Plans Workshop
  • OSU Extension Office-Fulton County, 8770 State Route 108, Wauseon, Ohio 43567
  • For Certified Crop Advisers who would like to become a NRCS Certified Nutrient Management Plan Provider Planner or NRCS/SWCD personnel.

March 23

  • Overholt Drainage School-Session 3
  • Baughman Tile Co., Paulding County, Ohio
  • SESSION 3: March 23 (1 day)Drainage Water Management: Controlled Drainage System Design and Installation; Friday 9:00 AM to 5:00 PM

March 29

  • Eastern Ohio Agronomy Day
  • Jefferson JVS, 1509 County Hwy 22A, Bloomingdale, OH
  • Soybean production is the focus of this eastern Ohio evening meeting.

March 31

Private Pesticide Applicator Recertification ends March 31st – check your license for your renewal year and find a meeting:




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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.