May 31, 2017 Weekly Crop & Weather Update

This update is also available in a print-friendly pdf format: May 31, 2017 Weekly Crop & Weather Update

Below you will find the daily maximum and minimum air temperatures, 2-inch soil temps, 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, 5/25 63 47 6.5 -
Friday, 5/26 72 51 11.5 T
Saturday, 5/27 81 50 15.5 -
Sunday, 5/28 73 53 13.0 T
Monday, 5/29 75 52 13.5 -
Tuesday, 5/30 67 48 8.5 0.05
Wednesday, 5/31 63 43 6.5 -

The cool weather discussed last week has remained in place here in southern Minnesota but drier conditions prevailed this week. Temperature averaged 59.9 degrees or 2.9 degrees cooler than normal. Rainfall totaled 0.05 inch which is 0.85 inch less than normal. Growing degree units (GDUs) totaled 75, 20% less than normal. Since May 1, we have now accumulated 309.5 GDUs, or 4% less than normal.

Last year this week was warm and wet. Temperature averaged 69.1 degrees and rainfall totaled 1.79 inches. Last year by the end of May we had accumulated 367 GDUs.

Some growth and development progressed this week when the sun did shine. Early planted corn is in the V4 (4 leaf collars) stage, but the bulk of the crop is still in the V3 stage. Soybeans have a wide range of growth stage where the earliest plantings are in the 1st trifoliolate leaf stage and some fields need to be planted yet. Patience has been key to watching some of the later planted crops come up this year. After a warm first half of May, the second half has been very cool. Crops planted in late April or early May only needed 7 to 10 days to emerge. This has not been the case with later plantings, but temperature explains the slow development later in May.

May temperature averaged 57.8 degrees or 0.7 degrees cooler than normal. This is the first month since August of 2015 that average temperatures have been cooler than normal. A record 20-month streak of above normal temperatures has come to an end. May was also wetter than normal with 5.1 inches of precipitation, 1.17 inches more than normal.

Rainfall and temperature can affect herbicide performance. The Minnesota Extension Service has put together a video demonstrating differences in of weed control from several herbicide modes of action. This information can be found by following this link: