August 9, 2017 Weekly Crop & Weather Update

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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, 8/3 82 64 23.0 0.05
Friday, 8/4 68 51 9.5 T
Saturday, 8/5 79 52 15.5 -
Sunday, 8/6 77 55 16.0 T
Monday, 8/7 75 57 16.0 0.09
Tuesday, 8/8 82 53 17.5 -
Wednesday, 8/9 87 56 21.0 -

The coolest weather we have seen since late June came to South Central Minnesota this week. Temperature averaged 67.0 degrees or 4.0 degrees cooler than normal. Rainfall totaled 0.14 inch, which is 0.92 inch less than normal. Growing degree units (GDUs) totaled 118.5, 17% less than normal. Since May 1, we have now accumulated 1710 GDUs. This is 3% more than normal.

Last year this week temperature averaged 72.4 degrees, rainfall totaled 0.27 inch and our growing season GDU total reached 1869.5.

Corn is in the R3 (milk) stage to early R4 (dough) stage. Cell division in the kernel is now complete and final yield will be determined by how much starch is accumulated in each of these cells.

Soybeans are in the R4 (full pod) to early R5 (beginning seed) stage. The crop is still susceptible to aphid outbreaks and scouting should continue through August.

Weed escapes have become evident in soybeans now and also in corn if giant ragweed has escaped and grown above the corn crop. It is generally to late to do anything other than physically removing these weeds. Farm managers should be aware of these weed species and be prepared to control them next year. For more reading on weed escapes from the Minnesota Extension Service, follow this link: