There is concern about how excessive potassium in the pegging zone (and other cations like magnesium) affect calcium nutrition. Certainly potassium at excessive rates can affect calcium availability and movement into developing pegs and pods in the upper few inches of soil (the pegging zone.) However, applying potassium at rates based on soil tests for peanuts should not be a concern, especially if the potassium is distributed throughout the soil profile prior to planting. The issue from a calcium nutrition standpoint is only in the upper 2-3 inches where pegs and pods are found. And, the potassium is needed further down, in the rooting zone. I have tried to create an issue in peanuts by applying a rate of potash (250 pounds/acre) that would be considered maintenance in many NC peanut fields. In those trials, I have never created a real issue, even when put on top of the soil right after planting. Based on these results, if you are applying K based on soil tests and/or are applying low rates just to maintain soil K levels, I would not be concerned about causing issues with calcium nutrition. I would, however, incorporate the K throughout the soil profile and apply the recommended rate of gypsum in a timely manner.