Last month I wrote that ethanol logistics MLP Green Plains Partners (GPP) "might have a volumes problem in the near future." This prediction was premised on the presence of weakening corn ethanol production margins that had the potential to result in lower production volumes at parent company Green Plains, Inc. (GPRE). The MLP's business model is based primarily on ethanol throughput volumes that are in turn almost entirely derived from Green Plains, Inc. This reliance benefited Green Plains Partners and its unitholders earlier this decade as Green Plains, Inc. embarked on