http://www.ag.ohio-state.edu/~corn/

CORN
Crop Observation and Recommendation Network

November 12 to November 26, 2001
C.O.R.N. 2001-37

In This Issue:

A) Scout Fields For Winter Annual And Other Cold Tolerant Species
B) Wheat Stand Establishment Problems In Northwest Ohio
C) Fall Sampling For Slugs
D) Regional Agronomy Meeting Agendas & Registration Now On-Line
E) Start 2002 Off On The Right Foot - Attend The Crop Production Conference

A) Scout Fields For Winter Annual And Other Cold Tolerant Species (Loux and Stachler) CORN Questions

The abundant rainfall in October, especially in Western Ohio and the mild fall temperatures made a good recipe for winter annual weeds. Fields that had mature marestail in them at the time of harvest should now be scouted closely for large numbers of emerging seedlings. Purple deadnettle and common chickweed are now present in fields that had few plants earlier. Scout fields closely that have a history of winter annual weeds, because they should be there now.

The warm weather this week makes it a great time to apply herbicides to control winter annual and other weeds. Dandelion, curly dock, and other cold tolerant perennials and biennials should still be growing enough to get good control of them at this time. Consult previous C.O.R.N. Newsletters as to what herbicides can be used to control winter annual and other weed species.

B) Wheat Stand Establishment Problems In Northwest Ohio (Pat Lipps) CORN Questions

Several weeks ago we were alerted to problems with wheat germination and emergence in Putnam Co and surrounding areas. A recent visit to the area and reports from County Extension Agents, indicate that the most severe fields are in the old lake bed region west of I-75 all the way into Indiana, south into Van Wert and Allen Counties and north into northern Henry and Defiance Counties. Stand losses range from only a few spots in fields to entire fields. Some counties are reporting as high as 50 to 80% of the fields lost. Areas that did not die had plants that were yellow to orange in appearance due to severe stress. The lack of stand establishment appears to be related to; 1) abundant precipitation in this are after planting in October, 2) when the wheat was planted, and 3) soil drainage. The worse fields were late planted just before the heavy rains. Those fields with poor drainage had the greatest stand loss. Over the past week many fields or sections of fields have been replanted.

We checked the rainfall records for the area and found that the first heavy rain occurred between Oct 4 and 6 depending on location, which totaled about 2.5 to 3 inches. The second period of rain was over a period of days, from October 10 to 17, when another 4 to 6 inches of rain fell. Precipitation totals for many of these areas for the month of October were above 10 inches. This means that many fields were saturated for a long period of time. It appears those fields that were planted soon after the Hessian Fly Safe Date (Sept 22-27 for NW Ohio) have the best stands, but those planted right before these rain periods had severe losses.

The stand loss was due to high precipitation during this since the wheat often survived where the tile lines were located. After digging up seeds and dead seedlings it was noted that a soft watery rot had killed them. This soft rot is generally associated with Pythium injury. We are now in the process of isolating this fungus from plants recovered from a number of fields sampled last week. Preliminary observations indicate a high percentage of rotted seeds have Pythium like colonies growing from them.

Stand establishment problems of this magnitude are not common in Ohio. Generally later planting, germination under protracted saturated soil conditions and ultimately being attacked by a soil-borne Pythium lead to the severity of the problem in these heavy NW Ohio soils. Seed treatments would not be expected to have a long enough lasting effect to have any impact on this situation. Three weeks of wet soils was too long a time for fungicide seed treatments remain active against Pythium.

The extent and magnitude of this damage will have an affect on wheat production in this area of the state. Surviving plants are small (usually with one main tiller only) at this time and need to develop several tillers before winter dormancy. Seed that has recently been replanted into affected areas will not have much time to grow before cold temperatures prevent further development. It is impossible at this time to evaluate the impact this will have on wheat production, but in early spring, after green up, growers should evaluate wheat stands before making nitrogen decisions on the crop.

C) Fall Sampling For Slugs (Hammond) CORN Questions

Fall slug sampling in Wayne County has suggested that slugs survived the summer in excellent shape. In fields with a history of slug problems, we are averaging 7-9 slugs per trap, with catches ranging from 3 to 20 slugs per trap.

There is still time over the next few weeks to sample slugs in your fields. Slug sampling can be done by placing about 10 square foot boards or roofing shingles throughout the field. Check under the boards after a few days. Move the traps to another location, and sample again in a few days. Sampling is best done following warmer nights without frost. Thus, sample in a morning when the temperatures remain above freezing.
Although specific thresholds are not available, knowing wether a field has a low or large number of slugs will assist in management decisions next spring. If numerous slugs are found, there is a greater potential for slug problems in the spring and closer observation of those fields. If few slugs are found, the chances for problems are lower. Fields checked so far have numbers that suggest they have a good potential for problems next spring.

D) Regional Agronomy Meeting Agendas & Registration Now On-Line (La Barge) CORN Questions

Complete program information for all eight Regional Agronomy Meetings being held throughout the state during the week of December 17 and January 14 are now on-line at:

http://www.ag.ohio-state.edu/~corn/Education/index.html

CCA credits and Pesticide applicator credits for both private and commercial license will be awarded. Pre-registration ends one week prior to each meeting. Pre-registration cost is $15. After the pre-registration period ends, registration are $20 space permitting.

E) Start 2002 Off On The Right Foot - Attend The Crop Production Conference (Brian Peach, OABA) CORN Questions

Circle Friday, January 4, 2002, on your calendar as the date for the annual Crop Production Conference. Ohio State University Extension and OABA host the Crop Production Conference, being held at the Fawcett Center on the campus of The Ohio State University. As always, OSU Extension Specialist offer the first glimpse at research projects, on-going programs and results offering valuable information to aid in making planning decisions for the upcoming season. Guest speakers are Dr. Bob Hoeft, University of Illinois discussing nitrogen management and starter fertilizer for corn, along with Dr. Tony Vyn, Purdue University talking about strip tillage.

The program is approved by the Ohio CCA Board for the following CEUs: Nutrient Management 1.5, Soil & Water Management 1.0, Crop Management 1.0, and Pest Management 1.5 for a total of 5.0 CEUs. ODA has awarded 1hr. of 2a (agronomic pest) and 0.5 hr. 2c (agronomic weed) for pesticide recertification credits. This is a great opportunity to get a good start on the New Year. Watch your mail for program and registration information.

Readers can subscribe electronically to this newsletter by sending an e-mail message to: corn-out-on@postoffice.ag.ohio-state.edu. A successful subscription message will receive by an automatic reply from the listserv. Contact your local Ohio State University Extension Office or e-mail labarge.1@osu.edu if you have problems subscribing.

Past versions of C.O.R.N. can be found on the World Wide Web at: http:/www.ag.ohio-state.edu/~corn/archive/

C.O.R.N. is a summary of crop observations, related information, and appropriate recommendations for Ohio Crop Producers and Industry. C.O.R.N. is produced by the Ohio State University Extension Agronomy Team, State Specialists at The Ohio State University and Ohio Agricultural Research and Development Center. C.O.R.N. Questions are directed to State Specialists, Extension Associates, and Agents associated with Ohio State University Extension and the Ohio Agricultural Research and Development Center at The Ohio State University.

Loux and Stachler, Pat Lipps, Hammond, La Barge, Brian Peach, OABA

Editor: Greg La Barge Web Editor: Tom Rosati

Information presented above and where trade names are used, they are supplied with the understanding that no discrimination is intended and no endorsement 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.

All educational programs conducted by Ohio State University Extension are available to clientele on a nondiscriminatory basis without regard to race, color, creed, religion, sexual orientation, national origin, gender, age, disability or Vietnam-era veteran status.

Issued in furtherance of Cooperative Extension work, Acts of May 8 and June 30, 1914, in cooperation with the U.S. Department of Agriculture, Keith L. Smith, Director, Ohio State University Extension.