UAV and Ground Image-Based Phenotyping: A Proof of Concept with Durum Wheat

Abstract

Climate change is one of the primary culprits behind the restraint in the increase of cereal crop yields. In order to address its effects, effort has been focused on understanding the interaction between genotypic performance and the environment. Recent advances in unmanned aerial vehicles (UAV) have enabled the assembly of imaging sensors into precision aerial phenotyping platforms, so that a large number of plots can be screened effectively and rapidly. However, ground evaluations may still be an alternative in terms of cost and resolution. We compared the performance of red-green-blue (RGB), multispectral, and thermal data of individual plots captured from the ground and taken from a UAV, to assess genotypic differences in yield. Our results showed that crop vigor, together with the quantity and duration of green biomass that contributed to grain filling, were critical phenotypic traits for the selection of germplasm that is better adapted to present and future Mediterranean conditions. In this sense, the use of RGB images is presented as a powerful and low-cost approach for assessing crop performance. For example, broad sense heritability for some RGB indices was clearly higher than that of grain yield in the support irrigation (four times), rainfed (by 50%), and late planting (10%). Moreover, there wasn't any significant effect from platform proximity (distance between the sensor and crop canopy) on the vegetation indexes, and both ground and aerial measurements performed similarly in assessing yield.2 of 25 principal goal for breeders. Durum wheat is, by extension, the main cereal cultivated on the southern and eastern shores of the Mediterranean Basin and one of the main cereals in southern Europe [4].Yield is a phenotypically complicated trait, not only because of its genetic complexity [5], but also due to the relative magnitude of gene-environment interactions [6,7], and it is one of the most integrative traits influenced by known and unknown factors. Thus, genotype evaluations in multi-environment trials are needed, at least in the advanced (generations) stages of selection. However, the major point at issue is that high-throughput plant phenotyping (HTPP) may still represent a bottleneck in breeding programs [7], owing to the need to increase the accuracy, precision, and throughput of the methodologies used, while reducing costs and minimizing labor [8,9]. Furthermore, HTPP approaches should allow multi-temporal trait-specific measurements to evaluate the yield components at different phenological moments.Nowadays, and almost by definition, HTPP implies the use of non-invasive remote sensing approaches of different nature [5,10], given the possibility of screening larger populations faster than conventional phenotyping procedures. Moreover, recent progress and advances in the technology of aeronautics and sensors have allowed the adoption of unmanned aerial vehicle (UAV) platforms, capable of precisely screening hundreds of plots in a short period of time [7,11]. Further benefits of the simultaneous c...

Using NDVI to Differentiate Wheat Genotypes Productivity Under Dryland and Irrigated Conditions

“…It appears that the optimal period to assess wheat grain yield may be during the early and late crop growth stages, while mid-season should be avoided for the reasons observed in this study. However, these results in contrast with [34] who observed better correlations to predict grain yield of 23 wheat genotypes in irrigated condition than rainfed condition during grain filling growth stages using handheld sensors and UAV platforms measurements, which performed similarly in predicting yield.…”

“…Plant genotypes respond differently to climate, soil type, irrigation, and other management practices, thus we need as many studies as possible to complement the existing literature. As the field of high throughput plant phenotyping (HTPP) for plant breeding and selection, is still in its infancy [30][31][32], this study is a valuable addition to this rapidly growing field [16,[33][34][35][36]. Use of several genotypes in this study adds breadth to the relationship between spectral measurements and yield in winter wheat.…”

Robust mosaicking of maize fields from aerial imagery

“…Downsampling the imagery produces smaller data sets that can be registered more quickly. Importantly, current phenotyping studies use either Pix4DMapper (Pix4D, Prilly, Switzerland) or AgiSoft (AgiSoft, St. Petersburg, Russia), both of which rely heavily on these strategies to produce canopy mosaics (Shi et al, 2016; Condorelli et al, 2018; Enciso et al, 2019; Gracia‐Romero et al, 2019; Johansen et al, 2019; Wang et al, 2019).…”

The Senescence (Stay-Green)—An Important Trait to Exploit Crop Residuals for Bioenergy

“…Approaches for a wide range of plant traits (morphological, physiological, phenological or ecological) are already been developed, evaluated and improved. We have used the heritability parameter as an indicator to compare across studies showing that both ground and aerial platforms combined with appropriate sensors and models have the potential to significantly contribute to the efficiency of breeding programs by increasing the accuracy of selection and subsequently the genetic gain [103]. However, in a broad sense we can assume that ground level platforms are mostly used as experimental solutions, almost always custom-designed and they are not considered to be the most suitable for implementing globally generalizable systems.…”