ROUSSEAUX Maria Cecilia
congresos y reuniones científicas
Ecophysiological responses of olive trees to experimental warming in two contrasting cultivars (Arbequina, Coratina).
ROUSSEAUX, M. C.; MISERERE, ANDREA; SEARLES, P.S.
Workshop; Olive cultivar adaptation and climatic change; 2017
Universidad Internacional de Andalucía
The globalwarming reported in the last decades represents a challenge for the oliveproduction of the Argentine Northwest, because the yield and the quality of oilin this region are strongly influenced by the temperature. The objective ofthis work was to evaluate the response of photosynthesis (A), transpiration(E), biomass production, yield and oil quality to the artificial increase ofmean air temperature in two olive cultivars (Arbequina and Coratina). Duringtwo consecutive campaigns (2014-15 and 2015-16) between the months of Decemberand May, two thermal levels (T0 and T +) were applied, using roofless cameras,on 64 olive trees of 2-3 years of age, growing without water limitations T0 andT + corresponded to the control treatments and 3-4 ° C above the control,respectively. In each season, three records of A and E were taken. Theproduction of biomass, its partition to the different organs, the production ofoil and its quality were quantified by harvesting whole trees at the end of thegrowing season (i.e., May). The efficiency in the use of water (EUA) wascalculated instantaneously from the measurements of A and E. The photosynthesisshowed no significant differences between treatments. In contrast, perspirationwas increased by 40% in the T + treatment compared to T0. As a consequence ofthe increase in E, in both growing seasons the EUA was significantly reduced by20% in the plants subjected to T +. The variations in the biomass due to thetreatments were explained by the effects of the treatments on the yield offruits and not by a direct effect of the temperature. In both cultivars T +negatively affected oil production, which showed average reductions of 30%. Thedecrease in oil yield was explained by a reduction in the individual averageweight of the fruits and a lower oil concentration, since the trees had asimilar load at the beginning of each year of the experiment. In comparison toT0, the fruits that grew under T + showed a lower proportion of oleic acid andan increase in the levels of some tocopherols, this effect of temperature wasmore accentuated in the Arbequina cultivar. Increases in temperature in theseregions would imply a greater consumption of water by the crop and would benegatively associated with production and oil quality.