Evaluation of active and passive sensor systems in the field to phenotype maize hybrids with high-throughput

New technologies, such as high-throughput precision phenotyping could offer an effective method of increasing genetic gains in breeding, as the screening of maize characteristics in the field remains a major bottleneck, whereas progress has been made in genomics technology. The architecture of tall maize plants presents a particular challenge to obtaining information about where reflectance-based information within the plant is collected to disentangle the contributions of the upper and lower leaves, as well as the stem and cob. High-throughput non-invasive assessments of a dedicated panel of seventeen diverse maize hybrids were conducted to assess the potential of two active sensors and one passive sensor to discriminate the biomass and nitrogen uptake. The passive sensor detected the nitrogen uptake of the entire maize foliage, whereas the sensing depth of the two active sensors was confined to the upper canopy layer. Although almost half of the nitrogen was stored in the stems, the reflectance values were primarily influenced by the foliage, with reflectance values from the remaining stems and cobs barely differing from that of bare soil. The results indicate that the sensing depth of various sensors needs to be taken in account, particularly when phenotyping tall plants, such as maize. (C) 2013 Elsevier B.V. All rights reserved.