Dear Farmers and perspective farmers.

This should be another great workshop. Chris DiFonzo is a great speaker and always provides easy to understand information on the latest of how to manage soybean pests (this time soy aphids and spider mites). 

Also if you are looking to use/purchase a different piece of equipment for land prep or harvest you should come and see… the demonstration of farm equipment.

Tomorrow Sept 15 at 3 pm in Williamston, mi (just east of MSU campus about 8 miles). Dinner is free but please call Connie at Ingham county office to reserve a spot for dinner if you come. 517-676-7207 or e-mail [log in to unmask]


Vicki Morrone

303 Natural Resources Bldg

C.S. Mott Group

Dept of CARRS

East Lansing, MI 48824

517-353-3542/517-282-3557 (cell)

[log in to unmask] for information on organic and sustaianable farming and news & events


From: Dan Hudson [mailto:[log in to unmask]]
Sent: Friday, September 11, 2009 5:04 PM
To: [log in to unmask]
Subject: Aphids, mites, and the September 15 tillage/corn varietyexhibition


Ag Clients,

Please see the memo from Chris DiFonzo (MSU Field Crops Entomologist) on the topic of the late-season appearance of spider mites and soybean aphids and what not to do about them.  Excellent points!

First, I want to remind you about the "Cutting Edge" Tillage Demonstration and MSU Corn Variety Trial Twilight Tour.  We have an excellent lineup of tillage technology -- more than eleven pieces of tillage equipment, many of them hitched to tractors and other technology that the vendors are hoping to highlight.  Jorgensen Farm Elevator and the Michigan Corn Growers Association have generously offered to sponsor the meal, and we will have a great opportunity to see how the varieties in the MSU Corn Variety Trial are shaping up.  Pre-registering will help us have enough food on hand.  To register, please either reply to this e-mail or call Connie at 676-7207.


The note about aphids and mites from Chris DiFonzo follows the text version of the flyer:


“The Cutting Edge” Tillage Demonstration and

MSU Corn Variety Trial Twilight Tour


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Join us on September 15 for a program covering two very important and interesting subjects: ‘cutting edge’ tillage and corn variety technologies!  We will begin at 3:00 at the Jorgensen Farm (2215 Dietz Road, Williamston), where we will see eleven different kinds of reduced/alternative tillage implements in action on wheat stubble.  These implements include:


Immediately after the tillage demonstrations, we will head over to the MSU Corn Variety Plots to have dinner followed by a tour of the plots, along with discussion and a yield estimating contest.  There is no charge for this event, but we request that you pre-register so adequate amounts of food are on hand.


To register, please call Connie at 517-676-7207 or e-mail [log in to unmask]


[log in to unmask]" v:shapes="_x0000_s1034">[log in to unmask]" v:shapes="_x0000_s1032">[log in to unmask]" v:shapes="_x0000_s1033">This program is presented by Ingham County MSU Extension with sponsorship from Jorgensen Farm Elevator and the Michigan Corn Growers Association.  Thanks to our sponsors!


Here is the note from Chris DiFonzo


Daniel Hudson
Agriculture and Natural Resources Educator
Ingham County MSU Extension
121 E. Maple Street
P.O. Box 319
Mason, MI  48854

Office Phone: 517-676-7207 ext 7291

>>> Chris DiFonzo  9/11/2009 8:25 AM >>>
Hi All:
I am receiving many phone calls about late-season populations of both
soybean aphids and mites.  Do not spray soybeans now for aphids or
mites! Here is my reasoning.

Fields planted at a 'normal' time (April - May):
#1. These fields are late-stage, R6 or later. The aphid threshold early in the season is 250, to prevent numbers from going over ~660 aphids per plant. After R5, we know the threshold is considerably higher, because  research studies sprayed late have no yield bump. The later season threshold at least 1000 (and probably more) per
plant - we just don't have a set number. No fields planted at the 'normal' time are at that level.

#2.  It's September. Days are shorter and colder. These conditions trigger soy aphid to turn into the male and female sexual stages that return to buckthorn to overwinter. So, the soybean aphid population is leaving the field on its own.

#3.  Most importantly The weather conditions are perfect for fungus. I know this because my garden collapsed last week in 2-3 days from fungus. I can't keep fresh fruit on my counter, probably due to the spores in the air. And white mold is rampant in many soy fields. These same conditions favor the fungi that kill aphids and spider mite.

Actually, spraying may in theory decrease the effect of fungi. We know that fungus infected aphids from the field can fly to buckthorn when they are sick. They die on buckthorn, spreading fungus to the treeline. There is evidence that an important mortality factor that contributes to lower populations of aphids NEXT year is killing them
in the treeline the PREVIOUS fall. So in theory you want a high enough population of sick aphids in your soybean fields to spread fungus to the treeline. Is that clear as mud?

Field plant late (June)
#1. These fields may be behind in plant stage and have more aphids than an early planted field. However, the points about aphids returning to buckthorn in September, and fungus killing aphids and mites, are the same for late planted beans as for early planted beans.

#2. Even if infested by high number of aphid or mites, what is the yield potential for some of these late planted fields in this cool season? On fields with low yield expectations, why throw good money after bad. How much yield will be lost by driving over beans (1-2 bu/ acre). Save the money and put it towards seed or herbicides for next season, or go to the Bahamas in January.

Chris DiFonzo




Have a great weekend!