Green Corn
Figure 1. Green, healthy corn benefiting from sunshine and warm weather.
Chad Lee, University of Kentucky
Last week, we talked about the yellow, puny corn around Kentucky. Today, Tuesday, May 30, 2017, much of the corn looks very different. It looks better. It looks green. It looks healthy!
Young corn plants were trying to live and function with limited sunlight, a lot of water and cooler temperatures. This was all occurring at a time when much of the corn was trying to switch over from the seed-based root systems to the nodal root system. All of those factors combined to make corn look yellow, striped, pale, and otherwise puny. The consecutive days of sunshine and warm weather have been just what those young plants needed to start growing. The air in the soil allowed for better water and nutrient flow into the plants. Those nutrients, especially nitrogen, allowed the young plants to produce more chlorophyll. The additional sunlight allowed those chlorophyll to make more sugars and that allowed these young plants to grow. Altogether, the young plants expanded their roots, turned green and began to grow.
Last week, we showed some images of a sulfur fertilizer study where one hybrid had a very noticeable response to sulfur, while other hybrids did not. Last week (May 24, 2017), you could easily identify the sulfur treatments in the research plots. Today, corn in all plots are a very healthy green color. There is no discernable different among the sulfur treatments. The sulfur fertilizer did provide a small boost in color to some of those plants. We will find out at harvest, if that boost early on was enough to increase yields.
Figure 2. One corn hybrid with greener plots of corn where sulfur fertilizer was applied. Image taken May 24, 2017.
The majority of corn around Kentucky was suffering from being young plants in cloudy, cool and wet conditions. The sunshine and warm weather should have solved the problem in most fields. If you have fields now that are still yellow, striped, or otherwise puny, you may want to doublecheck those fields. Look for compaction or insects or diseases. Doublecheck your soil nutrient programs. Fields with corn that still looks puny are the ones that may have bigger problems.
Figure 3. Green, healthy corn and no visible difference between plots with sulfur fertilizer and those without it. Image taken May 30, 2017.
Get ready for some extremely rapid growth of the corn crop. Every year, young corn plants seem to just sit, and sit, and sit. As we watch them just sitting there, we wonder if we did something wrong. Are the roots too small. Did we forget a fertilizer? Did we spray too much herbicide? Then, seemingly overnight that corn seems to explode in growth. What seemed to be only 2 feet tall yesterday is 4 feet today …. and seems like it will be 6 feet tomorrow. As corn enters about V6 to V8 growth stage, it will begin to grow very rapidly. This weather will encourage that growth. I fully expect corn a week from now to be much taller than corn today.
Farmers who sprayed various products last week on corn to try to the get them to “grow out of it” will feel extremely gratified by the green healthy appearance now and the rapid growth to follow. Farmers who did nothing and let the weather takes it course will feel extremely gratified as well. Hopefully, those farmers who did something left some checks to determine how much doing something helped. In our research plots, we have comparisons to help us learn.
So, enjoy the bright sunshine, because your corn already is. By the end of the week, we will all be asking when the next rain occurs.
Figure 4. Corn hybrids healthy and green after a few days of sun and warm weather.