July 26, 2017 Weekly Crop & Weather Update

This update is also available in in a print-friendly pdf format: July 26, 2017 Weekly Crop & Weather Update

Below you will find the daily maximum and minimum air temperatures, growing degree units (GDUs), and 24-hour precipitation amounts for this week. These values are recorded at 8 AM and reflect the conditions for the previous 24-hour period (8 AM to 8 AM) at the Southern Research & Outreach Center, Waseca.

Date Max Air Temp (oF) Min Air Temp (oF) GDUs Precip. (inches)
Thursday, 7/20 84 67 25.5 1.53
Friday, 7/21 86 70 28.0 0.06
Saturday, 7/22 80 69 24.5 1.01
Sunday, 7/23 87 66 26.0 -
Monday, 7/24 77 57 17.0 T
Tuesday, 7/25 78 62 20.0 0.08
Wednesday, 7/26 87 66 26.0 1.22

Warm and wet weather was seen this week across South Central Minnesota. Three separate rain events of greater than one-inch have soils very wet.  Temperature averaged 74.0 degrees or 2.1 degrees warmer than normal. Rainfall totaled 3.90 inches which is 2.90 inches above normal. Growing degree units (GDUs) totaled 167 or 14% more than normal. Since May 1 we have now accumulated 1491 GDUs. This is 5% above normal.

Last year this week was very warm but not quite as wet. Temperature averaged 78.6 degrees and rainfall totaled 1.08 inches. Last year at this time we had accumulated 1547.5 GDUs.

Corn is in the R2 (blister) stage. Examination of ears show pollination looks very good, but that was expected since we have seen very little stress from heat or drought. Soybeans are in the R2 (beginning pod) stage. All the rain this week has made it difficult for aphids to populate, but continue scouting throughout the season.

New technology in soybeans allow for the use of an old growth regulator herbicide (dicamba) to be used on soybeans that now have genetic tolerance to dicamba. Unfortunately, soybeans that do not have resistance to dicamba are very sensitive to low rates from volitility of the herbicide or physical drift of the product. Many soybean fields in the area are exhibiting injury symptoms from dicamba. The symptoms  are very easy to see but difficult to quantify with respect to potential yield loss.  It most likely looks a lot worse than it is.  For more reading on this crop injury from dicamba read the following link: http://blog-crop-news.extension.umn.edu/2017/07/the-dicamba-dilemma-facts-and.html