Phenotyping peanut drought stress with aerial photogrammetry and reflectance

Authors: BALOTA, MARIA - Virginia Tech; SARKAR, SAYANTAN - Texas A&M Agrilife; Bennett, Rebecca; BUROW, MARK - Texas A&M Agrilife

Submitted to: Agriculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/28/2024
Publication Date: 4/2/2024
Citation: Balota, M., Sarkar, S., Bennett, R., Burow, M.D. 2024. Phenotyping peanut drought stress with aerial photogrammetry and reflectance. Agriculture. 14(4):565. https://doi.org/10.3390/agriculture14040565.
DOI: https://doi.org/10.3390/agriculture14040565

Interpretive Summary: In many parts of the world, limited water in addition to climate change are significant challenges to the future of peanut production, and much work remains in developing drought-resistant cultivars. Peanuts respond to drought stress through physiological (e.g. chlorophyll content) and morphological (e.g. leaf folding and wilting) changes. Some peanut genotypes are able to produce good yields under drought, and peanut breeders can select for such drought-resistant genotypes by measuring physiological, morphological, and agronomic characteristics. However, physiological and morphological characteristics can be difficult to measure from multiple peanut genotypes at the field-level scale. To address this problem, data collected from 28 peanut genotypes using unmanned aerial vehicles (UAV) were compared to manually collected, ground-level data. The 28 genotypes were grown under drought and well-watered conditions. Several manual and aerial measurements were significantly correlated, indicating that UAVs can be used to evaluate peanut genotypes and select for drought tolerance. This information helps scientists develop more drought-tolerant peanut cultivars.

Technical Abstract: Peanut (Arachis hypogaea L.) responds to drought stress through changes in morphology, physiology, and agronomic characteristics, and breeders can select for more drought-tolerant peanut by measuring these changes. Agronomic characteristics such as yield are relatively easy to measure but may have low heritability, being dependent upon environmental effects. Morphological and physiological characteristics, which may have high heritability and allow best genetic gain, are difficult to measure at the field scale with sufficient accuracy. To this end, images collected from unmanned aerial vehicles (UAV) may provide accurate and efficient phenotyping of drought tolerance. Seven reference genotypes and a subset of 21 accessions from the U.S. peanut mini-core germplasm collection were selected for in-depth evaluation under well-watered and water-restricted conditions in Virginia in 2018 and 2019. Morphological, physiological, and agronomic characteristics were measured manually, as well as estimated from UAV images. Peanut genotype and water regime significantly affected all measured plant characteristics. Manual and aerial measurements were significantly correlated, but aerially-estimated traits appeared more heritable than manual measurements. In particular, carbon dioxide assimilation, stomatal conductance, and transpiration rates were efficiently estimated from the vegetation indices, indicating that UAVs can be used to phenotype and select for drought tolerance in peanut.