Our Illinois Corn in Early July

I'm not a farmer, although I live amongst corn. Some of you may know the phrase, "Knee high by fourth of July"? I've known that farmers want their corn much higher than that by early July, but I also know that having tassles by now is also not a good sign. Talk around here is that the corn is "stressed." Caleb I observed that as soon as the tassels came out, pollen (one of our vocab words) was falling down into the leaves. We also noticed that beetles were crawling all over the tassles, so we assumed they were our primary pollinator.  

In addition to tassels we also see one little baby silks sticking out in our corn. Caleb predicted that this will become our corn cobs. (Yeah!)

(We interrupt your regular scheduled program to bring you photo of cute kid eating corn! In addition to "seed corn," many of the locals have sweet corn. This is Corban's first summer for  eating sweet corn, and he loves it.)

Now back to our regular scheduled program...Since the corn is above our heads, we like to play follow the leader through one of the rows.

Caleb's interested in counting corn leaves has been improving.  I've even gotten HIM to count the leaves. A technique we use is to touch the leaves as we count them. And we noticed that they alternate sort of like a ladder. One leaf is on the left, then the right, and back and forth. We started counting in May, when there were 8 leaves, and the number has been steadily increasing. We've been making predictions each week too, and Caleb has been winning these little competitions. The number of leaves is now up to 19. 

Have you ever really looked at corn's root structure? Its quite amazing. At each node near the bottom of the plant, roots begin to emerge, moving downward, looking for soil. With the research I've done these roots are called nodal roots, brace roots, prop roots, or arial roots. All of the terms seem appropriate. They occur at the nodes, they act as a brace to prop up the plant, and since they are above the ground, they are arial.  Some plants we saw had these roots emerging as much as 2 feet off the ground. I see why engineers look to living structures to see how they've adapted. If you've ever built a building (out of blocks counts!) you know that having a wide base allows you to have a taller building! Same thing here! These arial roots provide the plant superior protection against wind.   

There were a couple of stalks down, and so Caleb and I photographed them. (He wanted to take them to the minor league baseball game...as we are the "Cornbelters.") I'm not an expert but you can see the fibrous roots in the center and the arial roots along the outside. 

Here are the other posts in our Corn Unit Series:

• Using Lego Guys to Learn about Corn 
• Measuring Plants (includes download of graphs for plotting plant growth)
• Unit Plan for our Plant Unit 
• Illinois Corn in Early July (this post) 
• Its all about the Kernel

For more information:
Root Development of Young Corn: Purdue University
Arizona White Maize Corn