July 27, 2016 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. 

Air Temp (oF) GDUs Precip
Date Max Min (inches)
Thursday, 7/21 90 71 28.5 0.02
Friday, 7/22 92 77 31.5 -
Saturday, 7/23 93 77 31.5 -
Sunday, 7/24 81 73 27.0 0.83
Monday, 7/25 82 61 21.5 -
Tuesday, 7/26 85 64 24.5 -
Wednesday, 7/27 87 67 26.5 -

Very warm conditions settled into southern Minnesota this week. Temperature averaged 78.6 degrees or 6.7 degrees above normal. The week was marked with three consecutive 90 degree days with very high humidity levels. Those conditions are difficult for people and livestock, but corn and soybeans fared pretty well. Rainfall totaled 0.85 inch or 0.15 inch less than normal. Growing degree units (GDUs) totaled 191. This is 30% more than normal. Since May 1, we have now accumulated 1574 GDUs, 9% more than normal.

Last year this week was wet when 4.07 inches of rain fell. Temperature averaged 72.2 degrees and we had accumulated 1408.5 GDUs.

Corn is in the blister stage and has begun the grain filling period. This will continue until maturity as corn will move nutrients into the developing kernels.

Soybeans are in the R4 (full pod) stage and some early planted soybeans are in the R5 (beginning seed) stage. Soybeans will continue to flower for a few weeks yet and favorable conditions this time of year will help boost yields. Soybeans in low areas that are too wet are a little yellow indicating dry weather would help for the next couple of weeks.

Small grains are ready for harvest. Spring wheat yields are about 60 bushels per acre and oat yields are about 110 bushel per acre in our trials.

Soil moisture measurements taken on July 19 show that we have 9.3 inches of available water in the top five feet. This is about 1.5 inches more than normal and could support crop growth for a couple weeks with no added precipitation.

Iowa State University has posted information on Forecasting and Assessment of Cropping Systems (FACTS). The information is for Iowa, but the yield forecast trends could likely be similar for southern Minnesota. Follow this link: http://crops.extension.iastate.edu/facts/weather to access ISU’s FACTS program.