Digital Imaging Delivers Rapid, Consistent Root and Leaf Measurements An Effective Tool in Product Development Plant roots are critical in defining yield in most agricultural ecosystems. Thus, the study of Root Systems Architecture (RSA) has gained considerable interest in recent years. RSA refers to the spatial configuration of the root system and includes root length, root weight, root volume, surface area, root-shoot ratio, branching pattern and horizontal distribution. It can be used to predict crop yield under various growing environments, such as drought, saturated, low fertility or alkaline soils. RSA also is useful to assess the performance of products such as biostimulants, biofertilizers, biofungicides, bioinsecticides and synthetic chemicals applied as seed treatments, soil drench or in-furrow. In the future, optimization of RSA may improve crop productivity, especially under low input or stress conditions. Ultimately, the goal is correlating lab RSA traits with crop productivity. However, low resolution and low throughput approaches for characterizing RSA impede this effort. Spatial evaluation of the root system is not an easy task. The root system of mature plants is quite complex and difficult to measure, while plant development after only 14 days of growth is relatively easy to measure. The primary challenge when evaluating root systems is the limited ability to phenotype and select the desirable traits underground at this early stage of their growth and relate them with growth and yield parameters. Methods such as root drawings, pin boards, auger/cores, rhizotrons, mini-rhizotrons, meso-rhizotrons, horhizotrons, mini-horhizotrons, rhizometers and hydraulic conductance flow meters have been used for root phenotyping in laboratory, greenhouse and field to quantify root growth. As roots changed over time, each method varied in reliability of measurements and results. Many of these methods are arduous, time-consuming and expensive.
ROOTS PERFORM A VARIETY OF FUNCTIONS IN PLANTS. They are responsible for the uptake of nutrients and water, mechanical support for the plants in soil and a site for interactions with beneficial and pathogenic microorganisms in the rhizosphere. Interaction of the roots with their environment depends on their morphology, architecture and distribution in soil profile. Morphology refers to the surface features of the single root, including how the root develops. Roots formed in the embryo are primary and seminal roots in corn/maize and tap or primary roots in legumes. The ones formed later from nodes on shoots are adventitious, secondary or lateral roots. Each type of root plays a different role in plant development and overall growth of plants. Distribution refers to root biomass or how deep it is in the soil, distance and angle from the stem. Morphology and distribution of roots depend on the genetic makeup and physiology of the plant and environmental factors.
