Performance of the Two-Source Energy Balance (TSEB) Model as a Tool for Monitoring the Response of Durum Wheat to Drought by High-Throughput Field Phenotyping.

David Gómez-Candón,Joaquim Bellvert,Conxita Royo

doi:10.3389/fpls.2021.658357

David Gómez-Candón, Joaquim Bellvert + Show 1 more

Open Access

https://doi.org/10.3389/fpls.2021.658357

Copy DOI

Abstract

The current lack of efficient methods for high throughput field phenotyping is a constraint on the goal of increasing durum wheat yields. This study illustrates a comprehensive methodology for phenotyping this crop's water use through the use of the two-source energy balance (TSEB) model employing very high resolution imagery. An unmanned aerial vehicle (UAV) equipped with multispectral and thermal cameras was used to phenotype 19 durum wheat cultivars grown under three contrasting irrigation treatments matching crop evapotranspiration levels (ETc): 100%ETc treatment meeting all crop water requirements (450 mm), 50%ETc treatment meeting half of them (285 mm), and a rainfed treatment (122 mm). Yield reductions of 18.3 and 48.0% were recorded in the 50%ETc and rainfed treatments, respectively, in comparison with the 100%ETc treatment. UAV flights were carried out during jointing (April 4th), anthesis (April 30th), and grain-filling (May 22nd). Remotely-sensed data were used to estimate: (1) plant height from a digital surface model (H, R2 = 0.95, RMSE = 0.18m), (2) leaf area index from multispectral vegetation indices (LAI, R2 = 0.78, RMSE = 0.63), and (3) actual evapotranspiration (ETa) and transpiration (T) through the TSEB model (R2 = 0.50, RMSE = 0.24 mm/h). Compared with ground measurements, the four traits estimated at grain-filling provided a good prediction of days from sowing to heading (DH, r = 0.58–0.86), to anthesis (DA, r = 0.59–0.85) and to maturity (r = 0.67–0.95), grain-filling duration (GFD, r = 0.54–0.74), plant height (r = 0.62–0.69), number of grains per spike (NGS, r = 0.41–0.64), and thousand kernel weight (TKW, r = 0.37–0.42). The best trait to estimate yield, DH, DA, and GFD was ETa at anthesis or during grain filling. Better forecasts for yield-related traits were recorded in the irrigated treatments than in the rainfed one. These results show a promising perspective in the use of energy balance models for the phenotyping of large numbers of durum wheat genotypes under Mediterranean conditions.

Highlights

Wheat is a staple food for humans, providing 18% of the daily human intake of calories and 20% of protein
When the analyses of the relationships between grain yield and the four traits assessed from remote sensing images (H, ETa, T, and leaf area index (LAI)) were conducted using the aggregated data of the three irrigation treatments for each flight event, the results clearly show that forecasts were much more accurate at anthesis and grain filling than at jointing (Figure 7)
This study shows the feasibility of using the two-source energy balance (TSEB) with very high resolution imagery to assess differences in the evapotranspiration components of a durum wheat panel

Summary

Introduction

Wheat is a staple food for humans, providing 18% of the daily human intake of calories and 20% of protein (http://www. fao.org/faostat/). Durum [Desf.] Husn) represents about 6% of a global wheat production of about 740 million tons per year (FAO, 2017). Wheat production per unit area needs to double by 2050 to meet the projected food demand of a global population forecast to be 9.22 billion. Achieving this objective is a significant challenge that will require increasing the current global yield increase rate of 1.3–2.4% y−1 (Ray et al, 2013), whilst at the same time minimizing the use of resources and the environmental impact (Tilman et al, 2011; Lal, 2016). The development of highyielding cultivars adapted to water-limited conditions is critical to guarantee food security

Objectives

Methods

Results

Discussion

Conclusion