Otomanguean loan words in Proto-Uto-Aztecan maize vocabulary?

A suite of words for the maize plant, its cultivation and cuisine can be reconstructed for Proto-Uto-Aztecan (PUA), suggesting that its speech community included cultivators. Evidence is presented that some of this maize vocabulary may have been borrowed from an early stage of Western Otomanguean, no later than the breakup of Proto-Oto-Chinantecan. If this episode of contact can be supported, PUA was probably located in the northwest quadrant of Mesoamerica, no further north than approximately Queretaro, at 5000–4500 years ago. The possibility that the PUA/Western Otomanguean resemblances are descended from some ancient common source is considered, but contact seems a better explanation.