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Showing posts from July, 2015

It's Time to Keep Track of Soybean Aphid Populations in Your Fields

Post was updated July 20, 2015

Soybean fields are being scouted in the region, with particular emphasis on soybean aphid and how populations are establishing and increasing.

Though field populations of aphids are quite variable, populations certainly are increasing as we would expect for this time of year. The majority of the fields we've scouted in the past two weeks were averaging under 20 aphids per plant HOWEVER we did have a few fields average from 50 - 60 aphids plant. In fields with these greater averages, the percent plants with aphids present were in the 90+ % range. Also within those greater number fields, we are finding randomly selected plants reaching into the 200+ aphid counts, though those plants represented only about 15% of the total plants randomly selected at individual sites.

The Downside of Insurance Insecticide Applications for Soybean Aphid

by Robert Koch (Extension Entomologist), Bruce Potter (IPM Specialist), Jeff Gunsolus (Extension Weed Scientist) 

For soybean aphid management, we encourage you to rely on scouting (actually getting into the field and looking at plants) and the validated economic threshold (average of 250 aphids per plant, aphids on more than 80% of plants, and aphid populations increasing) to determine when to apply insecticides for soybean aphid (see "Scouting for soybean aphid"). The threshold number of aphids is below the number required to cause yield loss and allows time to apply an insecticide before economic loss is incurred. However, you might be tempted to apply insecticides for soybean aphids at low population levels or without regard to the size of the aphid population in field, just in case you might have a problem. These "insurance" applications of insecticides can have negative impacts.

Armyworms in small grains

from Dr. Ian MacRae, UMN Entomologist, NWROC - Crookston

Folks,

We are receiving calls regarding armyworms in small grains in NW MN.

At this time they are small larvae (1/2"-3/4" long) and feeding in the lower foliage.  Scout for armyworms at grassy margins of the fields, low, weedy areas in fields or in lodged grain; populations are more likely to develop in these areas first.  Armyworms prefer the edges of leaves first and are messy, wasteful eaters.  They generally retreat during the day under soil and plant residue on the ground and feed more often beginning at dusk, it’s easier to scout for armyworm damage than the armyworms themselves.  Look for leaves that have been notched/cut, partially eaten leaf material on the ground, and small round pellets (armyworm frass, i.e. poop) near the base of the plants.

Iron Deficiency Chlorosis Refresher by Dr. David Franzen, NDSU Extension Soil Specialist

Following the significant rains of the past month/weeks, yellow soybeans are appearing across the region. So, rather than an entomologist like myself reviewing Iron Deficiency Chlorosis (IDC) for you, I have provided a write-up from Dr. Dave Franzen, NDSU Extension Soil Specialist, who does a much better job summarizing the topic than I could.

Phillip Glogoza

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Source:NDSU Crop and Pest Report Newsletter
Issue #9                                 July 2, 2015 
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Growers and crop consultants in the Red River Valley are well acquainted with iron deficiency chlorosis (IDC) through years of experience. Not everyone in the Valley (few, really) follow the best advice in dealing with it, but many growers have made great strides in the past 20 years in being able to live with it. A fully explained narrative of the causes of IDC in soybean is available in the soyb…

Subscribe for Postings to arrive by E-mail

When I moved the Cropping Issues in Northwest Minnesota on-line newsletter to the blog format, I have sought the best way to deliver updates to interested readers in a way that is efficient, quick and not too annoying. I have suggested using RSS feeds, subscribing to automatic updates (Atom), and my e-mailing a compilation of recent posts into a Table of contents with links. Each has had weaknesses in my opinion.

The best I have come up with at this point is a better performing e-mail option which is provided at the bottom of the right column and is the Follow By E-Mail option.

Simply enter your e-mail, click on subscribe and complete the submission process as directed through the pop-up window that will appear. Enter the text provided so the software knows you are a real subscriber.

I set this up a number of weeks ago. I have been very pleased with its performance and reliability in forwarding the postings. I also like the format it provides. When multiple posts are made in a given 24-h…

Post-Anthesis Foliar N Applications to Boost Grain Protein in HRSW.

Interest in improving grain protein in hard red spring wheat (HRSW) with in-season applications of nitrogen (N) fertilizer is on everyone mind, since protein premiums and discounts are rumored to be even greater this year than last. 

A "Cliff Notes" summary of foliar feeding of N immediately after anthesis can be found here.  The original Minnesota Crop News article, published in 2006 and reprinted in 2014, explaining the practice in more detail can be found here.

information provided by Jochum Wiersma