Mandan was released by the USDA based on the fact that it produces a large pecan that ripens early. However, ever since I first saw nut samples produced by this cultivar, I have not been a fan. The nuts produced by Mandan are indeed large (photo at right) but notice that the nut appears narrow when viewed suture side up (nut on left) compared to the width of the nut when viewed 90 degrees from the suture (nut on right). This shell geometry is always associated with pecans that produce kernels with narrow dorsal groves.
Our Mandan nuts averaged 7.65 g/nut and 58.64% kernel this year. These numbers look impressive but a quick look at the kernels makes you wonder how nutmeats that look so shriveled produce such high percent kernel. The upper side of the kernels often appear wrinkled and veiny. The narrow dorsal groves often traps shell packing material. The back side of every kernel was hollow and depressed indicating a less than perfect kernel fill. Overall, the kernels produced by Mandan were not up to my standards for exceptional kernel quality. When it comes to quality pecan kernels, Kanza and Pawnee are far superior.