ESTIMATING WATER STRESS IN AVOCADO TREES USING DRONEBASED THERMAL IMAGERY AND MICRO-SPRINKLER IRRIGATION IN PERU

Toledo-Choquehuanca J.; Huanuqueño-Murillo J.; Quispe-Tito D.; Galindosanchez M.; Pino-Vargas E.; Ramos-Fernández L. · Proceedings of the IAHR World Congress (2025) · DOI: 10.64697/978-90-835589-7-4_41wc-p1985-cd

Resumen

This research assessed water stress in Hass avocados by utilizing aerial thermography within the environmental context of La Molina, Lima, Peru. The study analyzed the vapor pressure deficit (VPD) and the crop water stress index (CWSI) from January to April 2023, aligning with the fruit set and growth periods in that region. To collect data, thermal and RGB (red, green, blue) images were taken using an H20T camera affixed to a Matrice 300 RTK unmanned aerial vehicle (UAV) and subsequently processed with Pix4Dmapper Pro software. Concurrently, soil moisture was gauged with a time domain reflectometer (TDR), and incoming solar radiation was captured using a radiometer across nine different surface types: aluminum, dry avocado leaves, green avocado leaves, expanded polystyrene, and various cloths in yellow, black, red, and green colors, along with bare soil. The thermal image data collected by the UAV and the radiometer exhibited a Pearson correlation coefficient of 0.978. The study's analysis indicated a gradual decline in the minimum Tc-Ta thresholds as VPD rose, with an upper temperature limit (UL) set at 8°C. Furthermore, it identified an inverse linear correlation between the CWSI and gravimetric moisture (θ), with Pearson coefficients of 0.849 in January and 0.522 in February and March. The results also showed that avocado plants respond to restricted water availability in the soil by closing their stomata to avoid dehydration.

Instituciones: Universidad Nacional Agraria La Molina; Universidad Nacional Jorge Basadre Grohmann