Dig to determine if a gap means a seed failed to emerge or was not dropped
July 3, 2019
“Sometimes it is the planter’s fault, but not always,” said Dave Nanda, PhD, SGD director of genetics, about gaps between plants. “You really owe it to yourself to find out whether there was a seed in there or not. If the gap is there because there’s no seed, then you need to go back to your planter.”
But sometimes a missing plant is not a planter problem at all, Nanda said. Instead, the seed may have been dropped by the planter but didn’t germinate. Or it germinated, but something prevented it from emerging.
Nanda proved his point during his initial visit to the #CornWatch19 field after corn emerged this spring. Checking for causes of gaps in rows can be easier earlier in the year, before a seed or seedling deteriorates, if there is one there. But it’s still possible in some cases to determine later in the season, as well.
Although the overall stand was 31,500 plants per acre — excellent considering the seeding goal was 32,000 seeds per acre — Nanda found spots here and there where there was a larger-than-normal gap between plants. Each time, he pulled out his pocketknife and gently began digging between the two existing plants within the row.
Four out of five times, he found a seed was planted. On one occasion, he couldn’t find a seed or seedling. Apparently, the planter didn’t drop one there.
“Assuming it was the planter’s fault every time might cause you a lot of effort chasing a problem that didn’t exist,” Nanda said.
In one spot, Nanda found a small seed that didn’t germinate.
“That’s going to happen,” he noted. “Typically, seed germination is tagged around 95 percent. That means there will be a seed here and there which doesn’t germinate.”
In the other three instances, Nanda found not only the seed, but a seedling that tried to develop. In each case, the coleoptile was twisted in various ways. The coleoptile never pierced the soil in any of these cases. To the casual observer, it was a planter skip — but it really wasn’t.
“It’s difficult to determine what might have happened to these isolated seedlings,” Nanda said. “It obviously was an isolated problem. Something caused the coleoptile to twist and curl rather than emerge normally.”
The bottom line is that by checking, one cause —planter failure— is eliminated.
Seed Genetics Direct is the sponsor of Corn Watch ’19. Stories are written by Tom Bechman.