Abstract
Accurate and efficient phenotyping has become the biggest hurdle for evaluating large populations in plant breeding and genetics. Contrary to genotyping, high-throughput approaches to field-based phenotyping have not been realized and fully implemented. To address this bottleneck, a novel, low-cost, flexible phenotyping platform, named Phenocart, was developed and tested on a field trial consisting of 10 historical and current elite wheat (Triticum aestivium L.) breeding lines at the International Maize and Wheat Improvement Center (CIMMYT). The lines were cultivated during the 2013 and 2014 growing cycle in Ciudad Obregon, Mexico, and evaluated multiple times throughout the growing season. The phenotyping platform was developed by integrating several sensors: a GreenSeeker for spectral reflectance, an infrared thermometer (IRT), and a global navigation satellite system (GNSS) receiver into one functional unit. The Phenocart enabled simultaneous collection of normalized difference vegetation index (NDVI) and canopy temperature (CT) with precise assignment of all measurements to plot location by georeferenced data points. Across the set of varieties, the Phenocart temperature measurements were highly correlated to a handheld IRT. In addition, CT and NDVI were both significantly correlated to yield throughout the growing season. The Phenocart is a flexible, low-cost, and easily deployable platform to increase the amount of phenotypic data that crop breeders obtain as well as provide high-resolution phenotypic data for genetic discovery.