Deficit irrigation at nursery stage induces drought acclimation mechanisms through the establishment of avoiding mechanisms and hardening processes. These include a better efficiency in water use (Davies et al., 2002) but also wood modifications such as denser vascular tissue (Hacke et al. 2001). In the experiment, we have submitted two ornamental species, Photinia x fraseri (evergreen) and Viburnum opulus (broadleaves) under deficit irrigation in order to make the material more resistant to drought, aiming to reduce water waste in Mediterranean urban areas. The experiment investigated plant physiological response during the treatment. It was conducted in Cespevi (Pistoia, Italy) where three plots of same age individuals grown under three water regimes during four months of acclimation. Control plot received enough water to replace the transpiration loss while two plots were respectively under severe water deficit (SWD=33%C) and moderate water deficit (MWD=66%C). The following parameters were assessed: i. leaf gas exchanges (carbon dioxide assimilation, transpiration); ii. water potential at pre-dawn and minimum water potential; iv. biomass. Deficit irrigation influenced leaf water content with lower values recorded in individuals under severe water deficit, and about leaf gas exchanges plants of control in both species shown a higher water loss for transpiration while carbon assimilation was significantly higher only in a few dates of measurement. The water use efficiency was rather similar among the treatments, in most dates, for both species. Concerning biomass allocation the control in both species recorded higher biomass in terms of leaves and branches dry weights and the differences with respect to the deficit treatments were significant.
Deficit Irrigation on Two Ornamental Species Commonly Used in Urban Gardens
Francesca Ugolini;
2012
Abstract
Deficit irrigation at nursery stage induces drought acclimation mechanisms through the establishment of avoiding mechanisms and hardening processes. These include a better efficiency in water use (Davies et al., 2002) but also wood modifications such as denser vascular tissue (Hacke et al. 2001). In the experiment, we have submitted two ornamental species, Photinia x fraseri (evergreen) and Viburnum opulus (broadleaves) under deficit irrigation in order to make the material more resistant to drought, aiming to reduce water waste in Mediterranean urban areas. The experiment investigated plant physiological response during the treatment. It was conducted in Cespevi (Pistoia, Italy) where three plots of same age individuals grown under three water regimes during four months of acclimation. Control plot received enough water to replace the transpiration loss while two plots were respectively under severe water deficit (SWD=33%C) and moderate water deficit (MWD=66%C). The following parameters were assessed: i. leaf gas exchanges (carbon dioxide assimilation, transpiration); ii. water potential at pre-dawn and minimum water potential; iv. biomass. Deficit irrigation influenced leaf water content with lower values recorded in individuals under severe water deficit, and about leaf gas exchanges plants of control in both species shown a higher water loss for transpiration while carbon assimilation was significantly higher only in a few dates of measurement. The water use efficiency was rather similar among the treatments, in most dates, for both species. Concerning biomass allocation the control in both species recorded higher biomass in terms of leaves and branches dry weights and the differences with respect to the deficit treatments were significant.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
