Under the current water crisis in agriculture, irrigation methods for saving and conserving
water are necessary. However, these methods must guarantee an appropriate yield with a concomitant
economic benefit and a reduced environmental impact. In this study, two irrigation thresholds for
irrigation timing (IT) based on thermal imagery were analyzed with the UNICA potato variety in
three trials under drip (DI) and furrow (FI) irrigation during 2017–2018 in Lima, Peru. The control
(T1) remained at >70% of soil field capacity. For other treatments, thresholds were defined based
on stomatal conductance at light saturation (T2: 0.15 and T3: 0.05 mol H2O m􀀀2 s􀀀1) and crop
water stress index (T2: 0.4 and T3: 0.6) based on canopy temperature. An integrated index (IIN)
was established for the valuation of treatments using the criteria of high fresh tuber yield (FTY) and
a low total amount of irrigated water, production cost (PC), and total C emissions (TE) and using
criteria of a score. FI-T2 (0.69–0.72) and DI-T3 (0.19–0.29) showed the highest and lowest IIN value,
respectively. FTY in T2 was not significantly reduced under FI, resulting in a lower PC regarding
DI–T2 and emphasizing the usefulness of thermal imagery in determining watering schedules in
potatoes under furrow irrigation systems.