Growers advised to continue irrigating to limit frost damage
By CAROL RYAN DUMAS
Cool weather has south-central Idaho's silage corn crop running two to three weeks behind, said Dave Sass, agronomist for Pioneer Hi-Bred International in the Treasure Valley.
"It's really immature and really wet," he said. While the corn is really wet, a good-quality crop is still possible. The key will be patience, he said.
"There's no advantage to try to go early and panic and start chopping," he said.
The immature, wet crop isn't worthless. Digestibility of the stalks is good. But growers won't see as much starch, so nutritional energy will be lower than if they let the crop mature, he said.
If growers do chop early, Sass suggests they use an inoculant in the pit, cover the pit and pay close attention to pit management. And they shouldn't overpack the pit or they'll end up with mush.
There's no way to know what yields will be, but he's expecting the average in the Treasure Valley. Kernels will probably be more shallow than normal, however.
The crop is still trying to mature, and farmers with fields with loamy, white, alkaline soil are having a tougher time than those with sandy soil. The loamy soil forms a crust that seals off the soil and reflects sunlight, so the soil beneath stays cool.
While growers are crossing their fingers to stave off frost, they should also continue to irrigate, he said.
While the crop isn't taking up as much water now, it will be laying in starch right up until it's cut. And keeping it irrigated will help protect against frost damage.
"You don't want the field dry until just before the choppers get there," he said. "Drought-stressed corn will suffer more frost stress."
In the Magic Valley, Rick Speicher, district sales manager for Land O'Lakes seeds, said it's the coolest year he's seen in 30 years. Across the state, the crop is 17 days behind.
"I have never seen a season this short, this cool. And we're not gaining any ground this month," he said, adding he expects below-average yields in the Magic Valley.
The first killing frost in the Magic Valley is typically at the end of September and a month later in the Treasure Valley.
"So the silage corn crop in the Magic Valley is more threatened. For the most part, there's been no killing frost yet," he said.
But growers in the Magic Valley are running out of time, and might have to chop a wet, immature crop. Corn that's too wet, however, is better than corn that's too dry, he said. If a grower has a lot of acreage he wouldn't be able to get to right after the first frost, he could end up with corn that's too dry. Too dry a silage doesn't pack well and traps a lot of air, which results in mold.
The forecast for the first full-moon cycle, which usually brings the first killing frost in the Magic Valley, shows no freezing temperatures. That should buy the crop another two weeks, Speicher said.
The sweet spot for moisture content is 67 percent, and 3 percent to 4 percent plus or minus is workable. Expecting lots of variation this year, Speicher recommends growers separate pits based on moisture content to make the pit easier to maintain.
Idaho silage corn stats
Year harvested acres yield per acre (bu.) production (tons)
2007 210 27.0 5,670
2008 215 27.0 5,805
2009 215 27.5 5,913