title: Unmanned aerial platform-based multi-spectral imaging for field phenotyping of maize.
abstract: BACKGROUND
  Recent developments in unmanned aerial platforms (UAP) have provided research opportunities in assessing land allocation and crop physiological traits, including response to abiotic and biotic stresses. UAP-based remote sensing can be used to rapidly and cost-effectively phenotype large numbers of plots and field trials in a dynamic way using time series. This is anticipated to have tremendous implications for progress in crop genetic improvement.
  
  
  RESULTS
  We present the use of a UAP equipped with sensors for multispectral imaging in spatial field variability assessment and phenotyping for low-nitrogen (low-N) stress tolerance in maize. Multispectral aerial images were used to (1) characterize experimental fields for spatial soil-nitrogen variability and (2) derive indices for crop performance under low-N stress. Overall, results showed that the aerial platform enables to effectively characterize spatial field variation and assess crop performance under low-N stress. The Normalized Difference Vegetation Index (NDVI) data derived from spectral imaging presented a strong correlation with ground-measured NDVI, crop senescence index and grain yield.
  
  
  CONCLUSIONS
  This work suggests that the aerial sensing platform designed for phenotyping studies has the potential to effectively assist in crop genetic improvement against abiotic stresses like low-N provided that sensors have enough resolution for plot level data collection. Limitations and future potential uses are also discussed.
authors.affiliation: International Maize and Wheat Improvement Center (CIMMYT), PO Box MP163, Peg Mazowe Rd, Mt Pleasant, Harare, Zimbabwe.
authors.forename: M
authors.identifier: 0000-0002-8120-5125
authors.initials: M
authors.lastname: Zaman-Allah
authors.affiliation: Plant Physiology Unit, Department of Plant Biology, University of Barcelona, 08028 Barcelona, Spain.
authors.forename: O
authors.initials: O
authors.lastname: Vergara
authors.affiliation: Plant Physiology Unit, Department of Plant Biology, University of Barcelona, 08028 Barcelona, Spain.
authors.forename: J L
authors.initials: JL
authors.lastname: Araus
authors.affiliation: International Maize and Wheat Improvement Center (CIMMYT), PO Box MP163, Peg Mazowe Rd, Mt Pleasant, Harare, Zimbabwe.
authors.forename: A
authors.initials: A
authors.lastname: Tarekegne
authors.affiliation: International Maize and Wheat Improvement Center (CIMMYT), PO Box MP163, Peg Mazowe Rd, Mt Pleasant, Harare, Zimbabwe.
authors.forename: C
authors.initials: C
authors.lastname: Magorokosho
authors.affiliation: Laboratory for Research Methods in Quantitative Remote Sensing (Quantalab IAS-CSIC), Cordoba, Spain.
authors.forename: P J
authors.initials: PJ
authors.lastname: Zarco-Tejada
authors.affiliation: Laboratory for Research Methods in Quantitative Remote Sensing (Quantalab IAS-CSIC), Cordoba, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Hornero
authors.affiliation: Airelectronics, 28223 Pozuelo de Alarcón Madrid, Spain.
authors.forename: A Hernández
authors.initials: AH
authors.lastname: Albà
authors.affiliation: International Maize and Wheat Improvement Center (CIMMYT), PO Box 1041, Nairobi, Kenya.
authors.forename: B
authors.initials: B
authors.lastname: Das
authors.affiliation: International Maize and Wheat Improvement Center (CIMMYT), PO Box 1041, Nairobi, Kenya.
authors.forename: P
authors.initials: P
authors.lastname: Craufurd
authors.affiliation: International Maize and Wheat Improvement Center (CIMMYT), PO Box 1041, Nairobi, Kenya.
authors.forename: M
authors.initials: M
authors.lastname: Olsen
authors.affiliation: International Maize and Wheat Improvement Center (CIMMYT), PO Box 1041, Nairobi, Kenya.
authors.forename: B M
authors.initials: BM
authors.lastname: Prasanna
authors.affiliation: International Maize and Wheat Improvement Center (CIMMYT), PO Box MP163, Peg Mazowe Rd, Mt Pleasant, Harare, Zimbabwe.
authors.forename: J
authors.initials: J
authors.lastname: Cairns
keywords: Maize; Nitrogen fertilization; Phenotyping platform; Remote sensing; UAP