How many times have you walked down a corn row, noticed an 8- to-12-inch gap between plants, and assumed no seed was dropped there? You chalked it up to less-than-perfect seed drop.
“Sometimes it is the planter’s fault, but not always,” Dave Nanda says. “You really owe it to yourself to find out whether there was a seed in there or not.”
Nanda is director of genetics for Seed Genetics-Direct, Jeffersonville, Ohio. Seed Genetics-Direct sponsors Corn Watch ’19. Nanda visits the field and makes observations at key points during the season.
“If the gap is there because there’s no seed, then you need to go back to your planter,” he says. Try to determine if there is a pattern to the gaps. Are they only in one row, or in multiple rows? That will help you determine if there was a potential problem on a specific row unit. Now is the time to make repairs — or at least make careful notes to ensure you return the planter to top condition before you begin planting in 2020.
There’s a seedling!
Sometimes a missing plant is not a planter problem at all, Nanda says. 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 Corn Watch ’19 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 have caused you a lot of effort chasing a problem which didn’t exist,” Nanda says.
EMERGENCE PROBLEM: In this case, the planter dropped the seed, so this wasn’t a planter problem. The seed germinated, but something cause it to remain below the surface instead of emerging properly.
In one spot, Nanda found a small seed that didn’t germinate. “That’s going to happen,” he notes. “Typically, seed germination is tagged around 95%. 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 says. “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, you eliminated one cause: planter failure, Nanda concludes.