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July 15, 2020

2020 U.S. Corn Rated 69% Good to Excellent, down 2%

Author: Michael Cordonnier/Soybean & Corn Advisor, Inc.

The condition of the U.S. corn crop declined 2% last week to 69% rated good to excellent. It was no surprise that the condition declined given the hot and generally dryer than normal conditions last week, especially in the central and southern areas. The U.S. corn crop is now 29% silking compared to 14% last year and 32% average. The corn is 3% in the dough stage compared to 2% last year and 3% average.

Once the corn reaches about 20% silking, the percent silking increases about 20-25% each week for the next two week. With 29% of the corn now silking, by next Monday, July 20th, the silking should be about 50% to 55% and by July 27th, it could be 70% to 75%. Therefore, about half of the corn will be pollinating over the next two weeks.

Rainfall late last week and over the weekend was better than expected especially across northern and central Illinois and western Indiana. For most of the Corn Belt, the forecast for this week is for generally seasonal temperatures with scattered showers. Temperatures will heat up later in the week especially for the some of the southwestern areas where temperatures could hit 100 degrees or hotter. Going forward, the weather across the Midwest will be determined by a high pressure dome that is expected to build across the region. How much it impacts the weather remains to be seen.

Even if the corn has adequate soil moisture, high temperatures can be detrimental to pollination success and early kernel development. The nighttime temperatures are also forecasted to be very warm as well, which could lead to increased levels of "dark respiration" and potentially lower yields.

Dark respiration occurs when the nighttime temperatures stay 72-73-74 degrees F or higher. These higher nighttime temperatures causes the corn plant to spend energy maintaining normal cellular activity instead of using that energy to fill kernels.

The soil moisture is getting dry in states such as Ohio (57% short to very short, Indiana (46% short to very short), Michigan (34% short to very short), and Illinois (28% short to very short). There are also dry pockets in Nebraska (47% short to very short), Kansas (45% short to very short), Missouri (40% short to very short), and southwest Iowa (40-60% short to very short).