Measurement of Viable Plant Roots with the Image Analyzing Computer1

Abstract

AbstractInvestigation of the spatial arrangement of plant roots in soils is limited by the time required to remove the roots from the soil and measure the viable roots. A root measurement technique is reported which includes differentially staining viable root tissue and extraneous organic matter with trypan blue, photographing the roots, and presenting the photographic negatives to an Image Analyzing Computer, which can predict root length or area in seconds. The staining procedure did differentially stain the viable roots and organic matter since addition of dried organic matter did not increase the Image Analyzer estimation of length or surface area. The photographic process, however, contributed to lower and more variable Image Analyzer estimates of root surface area when comparing specimens presented as photograhic negatives or in bulk without photography. The Image Analyzer provides reliable estimates of surface areas for root and wire samples presented in bulk with a coefficient of variation of 3.3 and 1.2%, respectively. This technique is relatively rapid and can be used to measure plant root systems sampled by soil cores.