Early daily trunk shrinkage is highly sensitive to water stress in nectarine trees

  1. Alejandro Pérez Pastor 1
  2. Rosa Sánchez, José María de la 1
  3. Ian C. Dodd
  4. Mª Rosario Saura Conesa
  5. Rafael Domingo Domingo 1
  1. 1 Universidad Politécnica de Cartagena
    info

    Universidad Politécnica de Cartagena

    Cartagena, España

    ROR https://ror.org/02k5kx966

Proceedings:
EGU General Assembly 2014

Publisher: European Geosciences Union, Vienna

Year of publication: 2014

Type: Conference paper

Abstract

The sensitivity to water stress of different plant water status indicators was evaluated during two consecutive years in early nectarine trees grown in a semi-arid region. Measurements were made post-harvest and two irrigation treatments were applied: a control treatment (CTL), irrigated at 120% of crop evapotranspiration demand to achieve non-limiting water conditions, and a deficit irrigation treatment (DI), that applied around 37% less water than CTL during late postharvest. The plant water status indicators evaluated were midday stem water potential (Ψstem) and parameters derived from trunk diameter fluctuations (TDF): maximum daily shrinkage (MDS), trunk daily growth rate (TGR), early daily shrinkage measured between 0900 and 1200 h solar time (EDS), and late daily shrinkage (LDS) that occurred between 1200 h solar time and the moment that minimum trunk diameter was reached (typically 1600 h solar time). The most sensitive (highest ratio of signal intensity (SI) to noise) indicators to water stress were Ψstem together with EDS. The SI of EDS was greater than that of Ψstem, although with greater variability. EDS was a better indicator than MDS, with higher SI and similar variability. Although MDS was linearly related to Ψstem down to -1.5 MPa, thereafter MDS decreased with increasing water stress. In contrast, EDS was linearly related to Ψstem, although the slope of the regression decreased as the season progressed, as in the case of MDS. Further studies are needed to determine whether EDS is a sensitive indicator of water stress in a range of species.