Ecophysiological responses of olive trees to warming in different phenological stages of crop development

SEARLES, P.S.; MISERERE, ANDREA; ROUSSEAUX, M. CECILIA

Rosario

Congreso; XXXIV Argentinian Meeting of Plant Physiology; 2023

Global warming is an important aspect of climate change. Yet, little research on how the vegetative growth and reproductive development of fruit trees will respond to increasing air temperature has been conducted. For this reason, a long-term research program was initiated in 2014 in northwest Argentina to study the effects of warming on young olive trees (Olea europaea L.). A series of warming experiments (+4 °C) have been conducted using open top chambers to assess responses during oil accumulation (summer and fall), early vegetative growth and reproductive development (late winter and spring), and chilling accumulation (fall and winter) for flowering. The results indicate fruit size as well as oil accumulation and its quality are reduced by warming, and that available carbon is preferentially allocated to leaf area. When warming in the late winter and spring, flowering is much earlier and there are adverse effects on fruit set that appear to be cultivar dependent. In contrast, shoot elongation is less affected by warming. The most important responses to warming appear to be related to chilling accumulation in the fall and winter, which is necessary for spring flowering. Flowering intensity is severely reduced by warming and the flowering period is much longer. It appears that fruit and oil yields in olive trees will be greatly reduced in northwest Argentina considering the currently available cultivars. Both adaptation strategies for current cultivars and a search for new cultivars could reduce the impact of warming in the coming