Dave Nanda pulled back shucks and checked ears for pollination success a few days ago in the Crop Watch '15 field. Nada is a consultant for Seed Consultants, Inc.
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"Pollination was somewhat ahead of what I expected based on the year," he says. Cool weather earlier in the season apparently didn't slow it down as much as he expected.
Overall, after checking ears from both hybrids, Nanda concluded that pollination appeared to be proceeding as normal. One hybrid had ears with silks turning brown, although all silks weren't brown and pollination was still going on.
Ears on the other hybrid, which tasseled and shot ear shoots about two or more days later, weren't quite as far along and weren't as brown overall.
The shake test, where you hold an ear and see if silks fall off, showed that a good portion of the ears checked were pollinated. If silks fall off, pollination has occurred. If they don't, that ovule hasn't been pollinated, and a kernel can't form until that occurs.
There were a few blanks here and there in some ears, he noted. And some ears almost took on a bi-color sweet corn appearance because some kernels, especially toward the tip, were just beginning to form. It was difficult to tell exactly which ones were pollinated and which ones were not pollinated.
The biggest thing now is whether tip kernels fill or abort, Nanda says. That may be determined by a variety of factors, including availability of nutrients, starting with but not limited to nitrogen, moisture reserves, temperature when the ear must make the decision whether to abort or keep the kernels and micro-climate around the plant.
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"Remember that the corn plant will do all it can to form and fill as many kernels as possible," Nanda says. "It believes that it is making babies for the next generation, so its goal is to complete the maximum number of viable kernels possible."