Canopy Temperature as a Key Physiological Trait to Improve Yield Prediction under Water Restrictions in Potato

Johan Ninanya,David A Ramírez,Jerónimo García,Javier Rinza,Roberto Quiroz,Cecilia Silva-Díaz,Marcelo Cervantes

doi:10.3390/agronomy11071436

Johan Ninanya, David A Ramírez + Show 5 more

Open Access

https://doi.org/10.3390/agronomy11071436

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Abstract

Canopy temperature (CT) as a surrogate of stomatal conductance has been highlighted as an essential physiological indicator for optimizing irrigation timing in potatoes. However, assessing how this trait could help improve yield prediction will help develop future decision support tools. In this study, the incorporation of CT minus air temperature (dT) in a simple ecophysiological model was analyzed in three trials between 2017 and 2018, testing three water treatments under drip (DI) and furrow (FI) irrigations. Water treatments consisted of control (irrigated until field capacity) and two-timing irrigation based on physiological thresholds (CT and stomatal conductance). Two model perspectives were implemented based on soil water balance (P1) and using dT as the penalizing factor (P2), affecting the biomass dynamics and radiation use efficiency parameters. One of the trials was used for model calibration and the other two for validation. Statistical indicators of the model performance determined a better yield prediction at harvest for P2, especially under maximum stress conditions. The P1 and P2 perspectives showed their highest coefficient of determination (R2) and lowest root-mean-squared error (RMSE) under DI and FI, respectively. In the future, the incorporation of CT combining low-cost infrared devices/sensors with spatial crop models, satellite image information, and telemetry technologies, an adequate decision support system could be implemented for water requirement determination and yield prediction in potatoes.

Highlights

Global food demand will increase because of the rapid population growth, which will reach around nine billion people by 2050; the agricultural sector will need more water resources to supply this demand [1]
The linear function fitted for the radiation use efficiency (RUE) calculus showed R2 values of 0.98 (p < 0.05) and
This finding agreed with other modeling exercises tested in this crop where water stress factors related to stomatal conductance response improved tuber yield prediction under different water restriction scenarios [16]

Summary

Introduction

Global food demand will increase because of the rapid population growth, which will reach around nine billion people by 2050; the agricultural sector will need more water resources to supply this demand [1]. Potato is the most important noncereal food security crop worldwide, highlighted by its high potential yield, elevated nutritional value, high water productivity, and wide climatic adaptability [3,4,5]. The maximum lightsaturated stomatal conductance (gs_max ), considered the most critical physiological trait to determine the crop water status [10], has recently been used to define optimal irrigation thresholds (0.15 mol H2 O m−2 s−1 ). This threshold value allows saving water without affecting potato yield [10,11]. The canopy temperature’s usefulness in irrigation scheduling has been highlighted in several studies [13,22,23]; this notwithstanding, its application to yield prediction by using crop models has been overlooked

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