A hypobaric apparatus and methods capable of inducing and maintaining in stored horticultural cellular tissue controlled pervaporation of undesired chemical compounds without reaching the boiling point of intracellular water molecules, comprising a hypobaric chamber constructed to provide a leak rate of less than 4.0 mm Hg per hour, sensors and regulators coupled to the chamber and to a controller to measure and regulate target correlates. Commodities processed, including processing storage periods longer than any known involving controlled atmosphere, exhibit an absence of low oxygen injury, high carbon dioxide injury, chilling injury, leaf abscission, leaf de-greening, fungal decay, bacterial decay, gravitational curving, geotropic curvatures, leaf epinasty, stem epinasty, flower fading, senescence, live invertebrates at any life stage, fumigant chemical compounds, volatile fungicides, volatile bactericides; no advance in ripening; minimal water loss.