Abstract: The present invention provides apparatuses for threshing plant material having seeds contained in pods. Preferably, an apparatus of the invention includes at least two threshing members between which plant material to be threshed is passed. The threshing members are generally constructed and arranged to exert a compressive force on the plant material as it passes therebetween. It is believed that the compressive force exerted on the plant material causes air trapped inside the pods to expand and force the pods open, releasing the seeds contained therein. Apparatuses of the invention include, for example, a pre-threshing apparatus, a vining machine and a harvesting machine. Preferably, an apparatus of the invention provides an efficient method for increasing the yield of undamaged seeds.