Thursday, September 18, 2014

How Did those Preemergence Herbicides Perform?

Lisa M. Behnken
Extension Educator, Crops
University of Minnesota Extension, Rochester

Lisa - 507-280-2867
Fritz - 507-280-2870

For many years now, Fritz Breitenbach and I have conducted corn and soybean weed management trials at our Rochester field location. We have a healthy population of giant ragweed, common lambsquarters and common waterhemp to evaluate in these trials - the three most common weed concerns of southern Minnesota farmers.

Do your soybean fields look like this?
In early July, we hold a tour to show folks the plots and talk about weed management systems - how can we do a better job. I mention this because we also encourage and welcome visitors to view these plots throughout the growing season..Seeing is Believing.

In the past few weeks, several groups have come to view these plots again -  yes, there is still something to see. The big interest, " How did those preemergence herbicides perform on giant ragweed and waterhemp?" Also, "What looks good, where are the weaknesses, are there new options and how did they perform, what other weed management options - non-chemical - do we need to consider, and finally how can we get the message across to folks?" Again, Seeing is Believing. Come and take a look.

Or, do they look like this?
There is still time to see how many of the herbicides performed. You are still invited and welcome to stop by and see the field trials at Rochester.  Please give Fritz or me a call and we will show you around the plots, share highlights and data from early ratings and discuss other options such as - What non-chemical options are you going to add to your weed management program next year?

Read more about Weed Issues - 'Got Weeds?  Evaluate Your Weed Control Program ' has been published to Minnesota Crop News.  http://blog.lib.umn.edu/efans/cropnews/2014/09/got-weeds-evaluate-your-weed-c.html



Thursday, September 4, 2014

Growing Concern about Growing Degree Days and the Corn Crop

Will we accumulate enough GDD to finish the corn crop? People are a bit concerned and talking about corn development - will it make it, will we have to dry most of the corn crop, etc.? I put an article together in 2009, comparing it to another cool year, 2004. In pulling that chart forward, adding 2014 and a long term average, 2014 doesn't look too bad for heat unit accumulation in southeast Minnesota (Rochester data).  We had a cooler than average July but a warmer than average August.  However, the issue is planting date.  Corn was planted in May this year, much after mid-May.  Delayed planting was also the problem in 2009.  We lost those early season heat units, at least a months worth, by not being able to plant in April.  Considering a May 15 planting date, we are at ~2100 GDD as of Aug 31.  For most corn grown in our region, we need around ~2400 GDD to reach black layer.  An average September (415 GDD) could do that for us, but corn at black layer is still 32% moisture. We will also need a nice October to help dry the crop.

For more information on corn drying and storage, check
NDSU Extension's Grain Drying and Storage (Kenneth Hellevang) website at: http://www.ag.ndsu.edu/graindrying

One last point - the accumulation of heat units around the state, planting and growing conditions have certainly not all been the same.  A good site to "check the numbers" in your location is at the Minnesota Climatology Working Group, Custom GDD: http://climate.umn.edu/cropddgen/cropddgen.asp


Growing Degree Days (Corn) for May through September






Lisa M. Behnken, UM Extension Educator, Crops
Rochester, MN