ABSTRACT
Reflective ground-cover film modified canopy microclimate and fruit oil content in a olive orchard in Southern Chile

Gaston Gutierrez-Gamboa1, Miguel Araya-Alman2, Sebastian Romero-Bravo2, Marcos Carrasco-Benavides2, Veronica Arancibia-Araya3, Jacqueline Campos-Yañez3, and Manuel Vial-Alarcon4*
 
Olive (Olea europaea L.) cultivation is expanding into non-traditional southern Chilean areas, where lower thermal accumulation and seasonal water constraints may limit fruit development and oil accumulation. This study evaluated the effect of aluminized low-density polyethylene (LDPE) reflective film applied as ground cover for 65 d from fruit development (BBCH 75) until harvest (BBCH 89) in a young ‘Arbequina’ olive orchard in Los Sauces, La Araucanía Region. The results showed that the reflective film increased photosynthetically active radiation from 510 to 950 µmol m-2 s-1 in the lower canopy (+86%) and from 360 to 760 µmol m-2 s-1 in the middle canopy (+110%), with nonsignificant effect in the upper or cross-canopy positions. The estimated leaf area index (eLAI) decreased from 2.25 to 0.95 in the lower canopy (-58%) and from 0.72 to 0.50 in the upper canopy (-30%), whereas leaf chlorophyll status remained unchanged. Midday stem water potential decreased from -0.92 to -1.24 MPa (-35%), suggesting increased evaporative demand around solar noon. Reflective film increased fruit DM at 60 °C from 45.55% to 48.00% (+5.4%), dry-basis fat from 39.45% to 43.93% (+11.4%), and fresh-basis fat from 18.17% to 20.07% (+10.5%), without significantly affecting fruit moisture. These results show that reflective film improved light availability in shaded canopy sectors and increased fruit oil percentage in cool-climate olive orchards, although the more negative midday stem water potential suggests that the treatment may also increase evaporative demand.
Key words: Arbequina, dry matter, olive fruit, orchard practices, plant microclimate.
1Instituto de Investigaciones Agropecuarias, INIA-Cauquenes, Cauquenes, Chile.
2Universidad Católica del Maule, Facultad de Ciencias Agrarias y Forestales, Curicó, Chile.
3Instituto de Investigaciones Agropecuarias, INIA-Intihuasi, Vallenar, Chile.
4Instituto de Investigaciones Agropecuarias, INIA-Carillanca, Temuco, Chile.
*Corresponding author (manuel.vial@inia.cl).
Received: 19 June 2026; Accepted: 10 September 2026, Available online: 29 October 2026.