The impact of material used for minirhizotron tubes for root research.

•  A wide variety of transparent materials are currently used for minirhizotron tubes. We tested the null hypothesis that minirhizotron composition does not influence root morphology and dynamics. •  Minirhizotron data were compared for glass, acrylic and butyrate tubes in apple (Malus domestica) and acrylic and butyrate tubes in a study with six forest tree species.