On the north side of Highway 281 west of Oelwein, Josh Peterson was operating a combine Tuesday afternoon harvesting his father’s soybeans, which were a dry brown.
Directly south of Highway 281, the corn stood firm, tall and as green as the John Deere tractor behind Darwin Peterson, Josh’s father. That corn was planted later in the spring because of wet conditions, and consequently is still too moist to harvest.
Up the hill, another field full of corn was brown and crinkled.
Area farmers have been out in their fields harvesting this week trying to stay ahead of more rain, which could begin as early at tonight.
A possible killing frost this weekend is also of concern to farmers with crops — such as the green corn — not ready for harvest.
In his Crop Notes report released Tuesday, Iowa State Extension agronomist Brian Lang said part of northwest Iowa is very likely experience a killing frost this weekend with temperatures of 28 fahrenheit or less. Northeast Iowa has a better chance of getting through the weekend without.
“National Weather Service (NWS) predicts nothing lower than 32F, but AccuWeather is less optimistic,” Lang said. “If we make it through this weekend in good condition, the next killing frost threat is not predicted until around Oct. 27.”
Lang added that “a partial frost that kills some leaf area has the same effect on yield reductions as insect feeding, foliar fungicide lesions, and hail damage. Reduced leaf area from any of these factors reduces photosynthesis and grain fill ... Yield losses are negligible if frost occurs when corn grain moisture is below 35%. Otherwise, yield loss is assumed to be directly proportional to the stage of maturity and the amount of leaf tissue killed.”
According to the Iowa Crop Progress and Condition report of Oct. 6, 55% of the corn in northeast Iowa is mature, although 98% has reached the dented stage. Statewide, 52% of the corn crop has reached maturity, more than two weeks behind average.
The report also said 5 percent of the state’s soybeans had been harvested, 12 days behind average. Only 4 percent had been harvested in northeast Iowa.