July 20, 2016 Weekly Crop & Weather Update

This update is also available in a print-friendly pdf format: July 20, 2016 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. 

Air Temp (oF) GDUs Precip
Date Max Min (inches)
Thursday, 7/7 85 65 25.0 3.03
Friday, 7/8 82 62 22.0 0.13
Saturday, 7/9 77 58 17.5 -
Sunday, 7/10 82 64 23.0 0.95
Monday, 7/11 80 64 22.0 0.18
Tuesday, 7/12 87 66 26.0 0.10
Wednesday, 7/13 83 69 26.0 -
Thursday, 7/14 82 59 20.5 0.12
Friday, 7/15 73 61 17.0 0.06
Saturday, 7/16 77 55 16.0 -
Sunday, 7/17 81 60 20.0 1.77
Monday, 7/18 84 61 22.5 -
Tuesday, 7/19 85 63 24.0 -
Wednesday, 7/20 84 70 27.0 0.23

After a few days in the wilderness of Canada, I am back in the row crop country looking at corn and soybean development again. We will have a summary of the weather for the last two weeks.

Rain has been abundant and nine of the last 14 days have seen measurable precipitation. Temperature averaged 72.1 degrees, only 0.2 degree cooler than normal. Rainfall totaled 6.57 inches, which is 4.57 inches more than normal. Growing degree units (GDUs) totaled 309 or 3% more than normal. Since May 1, we have now accumulated 1383 GDUs. This is 6% more than normal.

Last year this two-week period was good for crop growth and development with temperature averaging 70.4 degrees and 1.82 inches of rain fell. We had accumulated 1203 GDUs.

Corn is in the R1 (silking) stage. The number of potential kernels has been determined by now. Lack of moisture stress should be good for pollination. Final yield will now depend on kernel development through the grain-filling period. While corn is through the most critical time period for determining yield, soybeans are just entering that period. Most soybeans are in the R3 stage (beginning pod) stage. Soybeans will continue to flower for several weeks and yield will depend on how many of these flowers develop pods. Aphid populations remain low at this time, but continue scouting because they can populate quickly.

Soil moisture measurements taken on July 5 indicate we were under 6-inches of available soil moisture in the top 5-feet. This was well below normal. But the 6.57 inches received the last two weeks have replenished soil moisture.

The University of Nebraska is again providing corn yield forecasts, and indicate we have a better then 50% probability of above normal corn yields, I would agree with that. The forecast for the entire area can be found at: http://blog-crop-news.extension.umn.edu/2016/07/initial-forecasts-of-cor...