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Showing posts from September, 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.

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 option…

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 w…