Dave Nanda, the retired plant breeder who observes the Corn Watch ’21 field, wanted pictures of the growing point in cornstalks just before tasseling. So, I grabbed my camera and a pocketknife and took my 11-year-old grandson, Graham, to the cornfield. We found three stalks and sliced them open on the pickup truck bed. When Graham saw tiny ears inside, ranging from a miniature ear to one just ready to send out silks, the questions began.
“Grandpa, why is that real tiny ear so small?”
“It’s on a plant with 12 leaves. It is just starting to develop,” I said.
“Oh, look, Grandpa, what are those tiny hairs on it?”
“Let me see. My eyes aren’t that good, but you’re right. There are hair-like filaments just starting to grow. They are called silks,” I said.
“Grandpa, what are silks?”
“Graham, look over here on the biggest ear. See all these long green things? They are silks. Each one attaches to an ovule on the tiny cob,” I answered, just starting to wonder if I was in over my head.
“Grandpa, what is an ovule? Don’t you mean kernels?”
“An ovule is the female cell waiting for a pollen grain to fertilize it. Once it is fertilized, a kernel can form,” I said. This was getting deep!
“So where do the pollen grains come from?”
“They come from the tassel, the male part. Look at this 16-leaf plant. We can unroll the top leaves and see that the tassel is almost ready to emerge. It will release thousands of pollen grains.”
“So, the kernels produce these long silks, and pollen falls on them?
“Not exactly. A silk grows from each ovule. Once a pollen grain grows down the silk tube and fertilizes the ovule, a kernel forms.”