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Agronomic Crops Network

Ohio State University Extension


C.O.R.N. Newsletter 2013-20

Dates Covered: 
July 2, 2013 - July 9, 2013
Rob Leeds
Generalist Pollinators and Soybeans

Generalist Pollinators and Soybeans


As we get close to soybeans flowering across the state (growth stages R1-R2), we need to bring up an important issue related not specifically to honey bees, but to pollinators in general (albeit honey bees in soybeans is still a concern).  Although soybeans are a self-pollinated crop, generalist pollinators such as bumblebees and other solitary bees do visit soybean fields regularly during the crop’s flowering stage.  These pollinators will also visit other nearby sites, offering pollinating services to other plants including flowers and if present, vegetable crops.  Research out of Iowa State University indicates that many generalist pollinators make regular visits to soybeans and are at danger from insecticide sprays; researchers at the OARDC have recently joined these studies.

Luckily, there are few insect pests that reach economic levels during flowering in Ohio; almost all occur during pod development or seed fill stages (R3-R5).  Thus, when following an IPM strategy, little insecticide should be sprayed at flowering because a treatment application, as we all know, should only be applied when needed, when a threshold is reached, and not applied as a preventive application.   

However, we are aware that many growers are adding insecticides to spray tanks when applying fungicides for plant health purposes and even late applications of herbicides because: “Well, I’m going over the field anyway so I thought I’d add an insecticide for insurance purposes! The insecticide is relatively cheap and soybeans are worth so much!” As we have always stated, we do NOT recommend this practice, and feel an IPM approach is much better for everyone and everything, including the environment and in this case, pollinators. We NEVER recommend an insecticide application unless there is a need.  And with the recent information and concern about generalist pollinators, this caution is even more important.  To illustrate this potential problem, just two weeks ago there was a significant bumblebee kill in Oregon, when over 50,000 bumblebees were killed by an insecticide sprayed (in this case a material called Safari) on linden trees in a parking lot during a time period when the trees were in flower and being visited by bumblebees (read just one of the many articles that were written about this:,1MG0A,6LPXAW,5N4VO,1 ).  This was with an insecticide that had the warning about being highly toxic to bees on its label and the need to NOT spray flowering plants or trees!

Growers and applicators should remember, having read the label, that most insecticides have a statement about spraying around bees and on blooming crops. The typical statement is: “This product is highly toxic to bees exposed to direct treatment or residues on blooming crops or weeds. Do not apply this product or allow it to drift to blooming crops or weeds if bees are actively visiting the treatment area”.   Ohio goes further in that the Ohio Department of Agriculture addresses this concern under Regulatory Divisions & Programs, Plant Industry Division, Pesticide Regulations, Law and Statues, Plant Industry 901:5.

901:5-11-02 restrictions

(B) No person shall:

(15) Apply or cause to be applied any pesticide that is required to carry a special warning on its label indicating that it is toxic to honey bees, over an area of one-half acre or more in which the crop-plant is in flower unless the owner or caretaker of any apiary located within one-half mile of the treatment site has been notified by the person no less than twenty-four hours in advance of the intended treatment; provided the apiary is registered and identified as required by section 909.02 of the Revised Code of Ohio (, and that the apiary has been posted with the name and telephone number of the owner or responsible caretaker.

(16) Apply pesticides which are hazardous to honey bees at times when pollinating insects are actively working in the target area; however, application of calyx sprays on fruits and other similar applications may be made.

We continue to advise that growers and applicators maintain good communications with bee keepers near their fields to prevent and limit unintended problems. A listing of registered apiaries can be obtained from the Ohio Department of Agriculture. The list can be requested via e-mail to the address

Applicators should avoid spraying when bees are active in the field with flowering crops or weeds. Other times to avoid spraying are from 10:00 a.m. to 7:00 p.m. or when temperatures are above 65 degrees F. On extremely hot days, bees may be active later into the evening.

Follow label precautions that relate to drift and be aware of the potential risk to neighboring crops or areas. Filter strips or other conservation areas that border fields may have flowering plants with foraging bees. Bees have a long range and can forage up to two and one-half miles from the apiary.


Fields With A History Of White Mold

Fields With A History Of White Mold

This article is targeted to those producers who have had long term issues with white mold also known as Sclerotinia stem rot in soybean which is approximately 15 to 20% of Ohio’s acres.  We have numerous fields in the state where this has been a problem, the most recent year was in 2009.

Conditions that favor white mold are high plant populations, soybean growth conditions where the canopy closes early, high moisture conditions and cool night time temperatures.  Most importantly, is when highly susceptible varieties are planted.


1.       Plant resistant varieties.  In 2009, there were several varieties that were very susceptible that made it onto the market.  Those have since been replaced.  Now is the time to go back and check to see if the varieties have white mold resistance.  If in doubt, then treat it as a susceptible variety.

2.      Scout the field.  If the canopies are thick and closed, you may be able to find the very tiny apothecia (Lead Image).  These are the fungal fruiting bodies that form from the sclerotia.  They are a very pale pink in color, and the spores, which are formed in sacs on the top surface, are shot from these fruiting bodies and land on the flowers. 

3.      If you are producing soybeans in one of the historical white mold fields, AND THE WEATHER CONDITIONS CONTINUE TO BE WET WITH COOL NIGHTS then it may be time to consider a fungicide application.  The timing is critical and we target the R1 growth stage, when most, if not all of the plants in the field have at least one flower.    The target is the lower canopy, so spray volumes should be raised to 15 to 20 gal/A, slower tractor speeds, and higher pressures of at least 40 psi. 

4.      Producers have some additional choices for fungicides this year:

Fungicides that are currently labeled:

DuPont                                               Approach                            Picoxystrobin     

BASF                                                   Endura                                Boscalid

Valent                                                Domark                               Tetraconazole

Bayer                                                  Proline                                Prothioconazole

United Phosophorus Inc.               Topsin and others             Thiophanate methyl


Note:  if it turns hot and dry, as it did last year.  Very little white mold will develop.  So monitor temperatures and as always if you do apply a fungicide.  Leave some blank strips for comparisons later in the season.


New Stink Bug Fact Sheet

New Stink Bug Fact Sheet

A new stink bug fact sheet is now available on our Agronomic Crops Insects web site at  At this time, we are calling it a provisional fact sheet as we will be adding a few more pictures before we get it made into an official fact sheet.  However, with stink bugs becoming a greater concern in soybeans because of increased numbers of green stink bug and red-shouldered stink bug and the arrival of the brown marmorated stink bug, we felt the need to get this information out to growers as soon as possible.  Follow the C.O.R.N. newsletter for continued updates on stink bugs throughout the summer!


Agronomic Crops Calendar for July 2013


July 2

Cover Crop Field Day

OARDC NW Ag Research Station 4240 Range Line Road Custar, OH 43511

9 to 11 AM. Hear cover crop speakers, view demo cover crop plantings, cereal rye notill soybean, crimper/roller demo, cover crop supplies discussion

July 10

OSU Weed Science Field Tour

OARDC – Western Agricultural Research Station, 7721 South Charleston Pike, South Charleston, Ohio 45368

Review of weed control plots and issues with Dr Mark Loux at Western Agricultural Research Station. Registration starts at 8:30 and a field tour with presentations by OSU faculty, staff and students will start at 9 am. The cost is $30, which includes the tour book and lunch.  Pre-registration required. Please RSVP to Bruce Ackley,, or 614-292-9081.

July 17

Agronomy Field Day-Western Agricultural Research Station

OARDC – Western Agricultural Research Station, 7721 South Charleston Pike, South Charleston, Ohio 45368

2013 Western ARS Agronomy Field Day will be held on Wednesday, July 17, 2013 – 9AM to 3:15PM at OARDC – Western Agricultural Research Station. Pre-registration required, payable at the door $20. Register by email or phone to: Harold Watters (, 937 599-4227 or Joe Davlin (, 937 462-8016.

July 18

Nutrient Application Field Day Impact and Management of Phosphorus across Various Tillage Practices; A Nutrient Application Field Day

A quarter mile west of the intersection of I-75 and Hwy 582 which is about 6 miles north of Bowling Green.

To examine the impact of tillage on phosphorus loss and other crop production factors that influence crop yields, the following field day to be held July 18, 2013 from 8:30 AM, to 2:30 PM in Wood County, Ohio – a quarter mile west of the intersection of I-75 and Hwy 582 - about 6 miles north of Bowling Green. The program is free but an email RSVP is required to Please include your name and a phone number where you can be reached in the email. Contact Steve Prochaska at 740-223-4041 or with any questions. 

July 25

Field Crops Day-Northwestern Agricultural Research Station

NW Ag Research Station, 4240 Range Line Road Custar, OH 43511

Time: 9-11:30 am, the program is Free.

Topics include: “Fungicide in Corn: Let’s Pencil it Out” – Dr. Pierce Paul, “Phosphorus and Water Quality-Researching the Ag Link” – Greg LaBarge, “Soybean Plant Date and Seeding Rate from 10 Years of On-Farm Trials” – Dr. Laura Lindsey, “Re-examining Corn Seeding Rates: How Much is too Much?” – Dr. Peter Thomison, CCA  and Pesticide Recertification credits have been applied for. For information contact: Matt Davis – Station Manager, 419-257-2060 or

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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.