MSU resources to estimate corn maturity date and accurately determine corn growth stages as harvest approaches

Oct 18, 2019

By Bruce MacKellar

The National Weather Service in South Bend, Indiana, announced there was a potential for frost late overnight on Monday, Oct. 14, 2019, into early Tuesday morning for much of northern Indiana and southern Lower Michigan in areas away from Lake Michigan, as well as in portions of northwest Ohio. his has been the first widespread threat of frost in southern lower Michigan this fall. With the large number of acres of late planted corn across much of Michigan, the frost may impact corn that has not yet reached physiological maturity.

How much impact a frost may have will depend upon how far corn has progressed. A stretch of warmer than normal weather in September had helped to offset cooler than normal temperatures in late July through much of August. However, drought conditions and tar spot have slowed corn development in many southern Michigan corn fields.

Two resources are available from Michigan State University Extension to predict when corn hybrids may reach physiological maturity and to help identify the current stage of growth in corn fields. MSU agriculture climatologist Jeff Andresen has put together a video to show how to use the U2U GDD Decision Support Tool.

The tool can help producers to determine when corn should reach “black layer” based on the location of the field, the relative maturity group (RM) of the corn hybrid planted, and the GDD accumulation based on temperature data for the area.

MSU cropping system agronomist Mani Singh and graduate assistant Kaitlin Fusilier have developed a YouTube video to help producers accurately determine the reproductive growth stages of corn. This video can be found at "Corn Reproductive Stages."

Accurately assessing the stage of development can help you to assess the yield impact a frost or freeze can have on late planted corn, as well as provide an idea of how many additional growing degree days should be needed for the crop to reach maturity. The closer the corn is to “black layer," the less yield loss and test weight reduction is likely to occur. Frost damage to corn can occur when temperatures dip below 32 degrees Fahrenheit for an extended period of time or a freeze (below 28 F) for short periods. The most common damage during a light frost is leaf tissue damage. A freeze often kills both leaf and stalk tissues. Since the stalks can continue to provide carbohydrates to the kernels even when the leaf tissues are dead, the low temperature does matter in terms of potential damage and yield losses.

Source : msu.edu

Video: Dr. Emerson Nafziger: Nitrogen Fertilizer Rates for Corn

The Crop Science Podcast Show, Dr. Emerson Nafziger from the University of Illinois breaks down decades of nitrogen research. From the evolution of N rate guidelines to how soil health and hybrid genetics influence nitrogen use efficiency, this conversation unpacks the science behind smarter fertilization. Improving how we set nitrogen fertilizer rates for rainfed corn is a key focus. Discover why the MRTN model matters more than ever, and how shifting mindsets and better data can boost yields and environmental outcomes. Tune in now on all major platforms!

"The nitrogen that comes from soil mineralization is the first nitrogen the plant sees, and its role is underestimated."

Meet the guest:

Dr. Emerson Nafziger is Professor Emeritus of Crop Sciences at the University of Illinois at Urbana-Champaign, with degrees in agronomy from Ohio State, Purdue, and Illinois. His research has focused on nitrogen rate strategies and crop productivity. He co-developed the Maximum Return to Nitrogen (MRTN) model, which is widely used across the Midwest. His research spans N response trials, hybrid interactions, crop rotation effects, and yield stability.