Cool weather over the last week to 10 days could not have come at a better time for corn. As most of the corn fields in the Midwest have moved into pollination stage, weather and climate become critical factors in determining final yield, explained Laura Edwards, SDSU Extension Climate Field Specialist.
"Corn can be easily stressed during its brief pollination period, as both hot temperatures -mid-90s or higher - and dry conditions can negatively impact yield," she said. "It's probably safe to say that the cool weather of the last week or so will not harm corn, and in fact may extend the grain fill period."
Edwards added that the result may actually lead to larger grain size and that minimum temperatures in the 40s, such as those over the weekend (July 24 to July 25) in South Dakota, did not harm corn plants.
According to temperature data, this growing season the accumulated Growing Degree Days (GDD) are near normal for most of the corn growing region of South Dakota. Edwards said the forecast for the next one to two weeks calls for continued cooler than average temperatures across most of the state.
"There is some increased chance of rainfall in the same period, particularly across the southern counties of South Dakota. The only areas with the possibility of some climate stress are those corn fields in the far southeastern counties that are beginning to show some signs of moisture stress," she said. "Hopefully enough timely rains this week and next can prevent any substantial yield loss in that area during this critical period."