TORRES Myriam Mariela
congresos y reuniones científicas
Influence of Water Deficit on Olive Tree (Olea europaea L.) cv. Arbequina during the Winter in an Arid Argentinean Region
San Juan
Simposio; VII International Symposium on Olive Growing; 2012
Institución organizadora:
INTA,CRILAR-CONICET,UNSJ, UNCuyo, UCCuyo, UNDec, CREA, Gobierno de San Juan
The expansion of olive cultivation to new regions with different climate regime from that of the Mediterranean basin highlights the need of studies on how water availability affects the different olive phenological stages. It should be taken in account that evergreen plants perform photosynthesis at any time of year. The aim of this work was to study the influence of water stress during the pre-flowering period (middle June ? early September) on agronomic and physiological parameters of the olive tree (Olea europaea L.) cv. Arbequina in an arid Argentinean region (San Juan province). In winter season, the effect of two deficit irrigation levels equivalent to 50 and 0% of evapotranspiration (T1 and T2, respectively) was analyzed comparing these with a control treatment without water stress (100% ETc, T3). After 15 d, both soil volumetric water content (SVWC) and leaf water potential (PHL) were substantially lower in the unirrigated treatment (T2 vs T1 and T3). These differences in PHL and SVWC were consistent throughout the experimental period in treatments with water deprivation (PHT: -7.7 MPa, -4.5 MPa and -2.4 MPa in T2, T1 and T3 respectively; SVWC: 4.97 %, 10.95 %, 15.51 % in T2, T1 and T3 respectively). A reduction in leaf gas exchange parameters, including leaf conductance (gs), was also observed 15 d after water deprivation in olives trees growing under non-irrigated condition and this tendency was more pronounced toward the end of the trial (T2 < T1 < T3, p ≤ 0.01). The results from this assay showed that the number of flowers/inflorescence was reduced significantly by a mild water deficit treatment, but not the fruit set, having a positive impact on tree productivity. However, the unirrigated treatment (T2) did not blossom, probably due to the death of the floral bud. Therefore, this fact affected the fruit yield and as a consequence an increased vegetative growth after rewatering was observed (T2 >T1 = T3, p ≤ 0.01). These preliminary results suggest that only mild water stress could be implemented in the winter period. And this strategy could be a valuable tool to increase the olive tree production in arid Argentinean areas.