In the North Dakota State University Weekly Crop & Pest Report, issued today, agronomist Joel Ransom tells us that corn planting has moved forward at a
record pace, though recent storms have stopped some farmers again. Here is a picture of a field of corn west of Buffalo, N.D., in western Cass County, where a friend gave a Sunday afternoon crop tour. The farmer, in this case, says he was pleased with the progress of corn on May 26. Soybeans were planted. Dry edible beans were about to be planted.
Some farmers in the area seemed unhappy with the crop progress, the farmer said, but he thought things were looking good.
Ransom sees it on a larger scale, and puts it this way: “On average,
corn has been planted later than is ideal,” Ransom wrote in his report. “Earlier planted
fields are now beginning to emerge.”
Corn requires about 120 GDDs to emerge (a bit later if planted deeper than 2
inches or for fields with moderate to heavy residue cover), he says.
Corn growing degree days can be used to predict
emergence and leaf appearance in most environments.
Data from North Dakota suggest that new leaves appear after about
70 GDDs. So corn planted on the 1st of May should be at
about the “two collar leaf stage,” while corn planted on May 15should just be emerging.
“GDDs are running behind
normal for the latter half of May, which is good news for
the small grains, but not for corn,” Ransom says. “Not only is above-ground
development of corn delayed by cool weather, but the root
system is also impacted. It is not unusual for corn to appear
yellow and nutrient deficient when soil temperatures hover
around 50 degrees.”
Extensive root development is needed
for the corn plant to find and take up phosphorous. Even
when a “pop-up” fertilizer is applied, the plants may appear
yellow until temperatures warm up and root growth
increases. The best cure for yellow corn seedlings at this
time is a good dose of warm weather.