Fig. 1.

The choice of phenotyping under controlled conditions vs. field environments depends greatly on the purpose of phenotyping, heritability of the trait, and logistical considerations of data collection. a High-clearance tractor measuring the height, temperature, and spectral reflectance of young cotton plants. Such a system is reasonably high-throughput and can measure canopy traits with high accuracy and precision. These traits typically have high heritability and are considered component phenotypes of yield under drought stress (reprinted from White et al. 2012, copyright 2012, with permission from Elsevier). b Ten-day time course of root system growth in three dimensions of two divergent varieties of rice from Clark et al. (2012). Roots are notoriously difficult to phenotype in the field and root architecture in particular. This phenotype lends itself well to controlled conditions as the logistics of evaluating roots are more tractable, and it permits the exploration of otherwise un-surveyable phenotypes such as center of mass and dynamic tracking of architecture development over time (copyright American Society of Plant Biologists)