Potato harvest

Potatoes are harvested in the Pleasant Valley area northwest of American Falls. Area farmers are concerned about their unharvested potato fields, with extreme cold in the forecast for Wednesday and Thursday nights.

Roughly an inch of snow fell on James Hoff’s potato fields south of Idaho Falls on Wednesday as he and his crews raced to bring in the rest of the crop.

Hoff hoped to be 100 percent done with his harvest by Wednesday night, ahead of the record-cold temperatures that arrived Thursday morning and were also predicted for Friday morning.

Hoff says they'd been starting early each day throughout the week despite the cold temperatures in the mornings, risking the potential for shatter bruising — referring to cracks that can damage the skin.

“(If you start when it’s) too cold, you can shatter bruise the potatoes,” Hoff said, but added that that’s better than the alternative. “If they freeze in the ground, that’s not good either.”

A strong cold front moved into the region on Tuesday night, bringing wind, snow and chilly temperatures that have threatened unharvested crops throughout Idaho.

The National Weather Service reported the low temperature at the Pocatello Regional Airport set a record of 16 degrees at 7 a.m. Thursday morning. The area’s record daily low for Oct. 10 was 18 degrees, set in 1985, and for Oct. 11, it’s 19, set in 2003.

The Rexburg area also reached a low of 16 degrees, though officials say the area lacks sufficient data to justify records. Friday morning lows were expected to drop to about 11 degrees in Rexburg and 13 degrees in Pocatello.

“There are crews digging potatoes now as rapidly and as fast as they can to get them dug and pulled out of the ground before that big bunch of weather hits tomorrow,” Lance Ellis, a University of Idaho Extension educator for Fremont County, said prior to the arrival of the extreme cold.

Ellis says that a combination of late planting season combined with cooler weather and frost slowed down the harvest. Ellis has met with Fremont County farmers and has noted some stress in the air.

“Farmers don’t panic too much,” Ellis said, prior to the arrival of the cold weather. “They are working very, very hard to try and get as much done as they possibly can. ... A lot of them are hoping they can either get them dug (or) that this winter storm will come through (and won’t) damage the potatoes too badly. It would be best if they all could get the potatoes dug and in the cellars.”

University of Idaho Extension researchers Nora Olsen and Mike Thornton offered growers a list of tips, circulated by the Idaho Potato Commission, for coping with the cold.

“Probability of frost damage occurring on some of the crop is high,” they wrote. “Although weather is always hard to predict, it appears cooler temperatures will prevail over the next 10 days, providing little reprieve to wait for warmer weather. The cooler temperatures will decrease the window of opportunity to harvest at or above recommended temperatures.”

The researchers warn that cold pulp temperatures dramatically increase the risk of both shatter and blackspot bruising and to be vigilant about lessening impacts and minimizing drops, keeping chains full on harvesting equipment. They advised green potatoes have a higher chance of frost and to pick out all green potatoes heading into storage.

“As frosted potatoes break down in storage, they give off considerable water and increase overall humidity in the storage,” they added. “Factor the additional water in and adjust humidification as needed. You will need to dry out the frosted potatoes with a strong ventilation and reduced humidity program.”

Furthermore, frosted potatoes have a higher potential of developing soft rot, they wrote.