If a corn plant emerges one, two, or three days after its neighbour, will it yield less?
We’re about to find out as Corn School makes its first return visit to the flag test that Real Agriculture resident agronomist Peter Johnson planted this spring.
National Corn Growers Association yield contest champion Randy Dowdy, who harvested a record 503.7 bushels per acre on his Georgia farm competition plot in 2014, believes that even emergence is indeed the silver bullet when it comes to corn production. He believes a flag test is a great way to assess the yield impact of later-emerging corn plants.
This spring, Johnson set out to test Dowdy’s theory under Ontario conditions. In Part 1 of our flag test series, Johnson explained how after planting he visited his test plots for seven consecutive days to flag plants as they emerged.
In Part 2 of this video series Johnson now heads back into the plot before harvest to take a look at how early-emerging cobs compare to slower-emerging laggards. Along the way he discovers that many factors other than emergence are also at play – from row spacing, impact of tillers, kernel size and much more.
“Does emergence matter? Absolutely!” says Johnson. “But there are things that happen after emergence that we don’t understand that create some of these differences.”
Stay tuned for a final report when Johnson calculates the actual yield and quantifies what’s he’s learned from the corn flag test.