Search results for " transpiration"

Plant response to irrigation with saline water in a Sicilian vineyard: results of a three-years field investigation

2012

This paper reports the results of a three-year field investigation carried out in a vineyard located in Sicily (Mazara del Vallo, Trapani) within the framework of the Project: Evolution of cropping systems as affected by climate change (CLIMESCO). Research investigated soil-plant response to irrigation performed with water having two different salinity levels; soil hydrological characteristics, soil salinity, crop transpiration and stomatal conductance were measured in field plots. The results proved that crop transpiration and stomatal conductance were significantly affected by soil salinity conditions (expressed as electrical conductivity of the soil saturated water extract). A significan…

Does short-term potassium fertilization improve recovery from drought stress in laurel?

2014

Xylem hydraulic conductance varies in response to changes in sap solute content, and in particular of potassium (K(+)) ion concentration. This phenomenon, known as the 'ionic effect', is enhanced in embolized stems, where it can compensate for cavitation-induced loss of hydraulic conductance. Previous studies have shown that in well-watered laurel plants (Laurus nobilis L.), potassium concentration of the xylem sap and plant hydraulic conductance increased 24 h after fertilization with KCl. The aim of this work was to test whether water-stressed laurel plants, grown under low potassium availability, could recover earlier from stress when irrigated with a KCl solution instead of potassium-fr…

Responses of Prunus ferganensis, Prunus persica and two interspecific hybrids to moderate drought stress

2003

Prunus ferganensis (Kost. & Riab) Kov. & Kost, a close relative of the cultivated peach (Prunus persica (L.) Batsch.), is native to arid regions of central Asia and may possess traits valuable for improving drought tolerance of commercial peach varieties. One distinguishing feature of P. ferganensis is its prominent, elongated, unbranched leaf venation pattern, which behaves as a simple recessive trait in segregating populations of P. ferganensis x P. persica hybrids. To understand whether this trait could be used as a marker in breeding for drought tolerance, we investigated the association between leaf morphological and physiological parameters related to drought response in P. ferganensi…

A comparison of growth, gas exchange and productivity in Olea europaea cultivars growing on Mediterranean hills.

2008

This work concerns the ecophysiology of olive cultivars growing on Mediterranean hills. Our aim was to quantify the photosynthetic efficiency of the cultivars in cultivation. In two hill areas, we tested the phenological and ecophysio- logical variability of olive cultivars grown on non-irrigated land, with different pedo-climatic characteristics. Cultivation area 1 falls within a natural protected area, while area 2 is on farming land. The cultivars selected (‘Biancolilla’, ‘Nocellara del Belice’ and ‘Giarraffa’) belong to the local genetic pool and require different amounts of water. We followed the phe- nological phases of shoot growth and drupe production. We studied leaf anatomy and ch…

A portable NMR sensor to measure dynamic changes in the amount of water in living stems or fruit and its potential to measure sap flow.

2014

Nuclear magnetic resonance (NMR) and NMR imaging (magnetic resonance imaging) offer the possibility to quantitatively and non-invasively measure the presence and movement of water. Unfortunately, traditional NMR hardware is expensive, poorly suited for plants, and because of its bulk and complexity, not suitable for use in the field. But does it need to be? We here explore how novel, small-scale portable NMR devices can be used as a flow sensor to directly measure xylem sap flow in a poplar tree (Populus nigra L.), or in a dendrometer-like fashion to measure dynamic changes in the absolute water content of fruit or stems. For the latter purpose we monitored the diurnal pattern of growth, ex…

Plant Response to Saline-Water Irrigation in a Sicilian Vineyard

2012

This chapter presents results of a 3-year field investigation in a vineyard located in Sicily (Mazara del Vallo, Trapani) within the framework of the Project “Evolution of cropping systems as affected by climate change” (CLIMESCO). Soil-plant responses to two saline irrigation waters were determined by measuring soil hydrological characteristics, soil salinity, crop transpiration and stomatal conductance in field plots of a Sicilian vineyard. The results proved that crop transpiration (T r) and stomatal conductance (G s) were significantly affected by soil salinity conditions, expressed by electrical conductivity of soil saturation extract (ECe). Significant reductions in T r and G s were f…

Kairomone involvement in the host specificity of the egg parasitoid Trissolcus basalis

2006

This paper reports the results of a comparative laboratory analysis of the behavioural responses of the egg parasitoid Trissolcus basalis (Wollaston) (Hymenoptera: Scelionidae) to semiochemical cues from four species of pentatomid bugs, Nezara viridula (L.), Eurydema ventrale Klt., Murgantia histrionica Hahn. and Graphosoma semipunctatum F. (Heteroptera: Pentatomidae). In a Y-tube olfactometer, T. basalis was attracted by volatile chemicals from N. viridula, but not from other pentatomid species. In an open arena, the parasitoid reacted to chemical trails left on filter paper by all the species but most intensely to those left by N. viridula. However, upon encountering pentatomid eggs, T. b…

Mass transfer in channels in the presence of wall transpiration

Mass transfer to or from transpiring walls is studied. Examples from different fields of engineering, notably involving membrane processes, are illustrated, and analogies or differences with respect to heat transfer problems are discussed. With special reference to plane channel flow, suitable dimensionless parameters are introduced, and the dependence of the Sherwood number upon these parameters is computed by a number of approaches of different complexity, from two-dimensional CFD to simple algebraic correlations.

Diurnal Regulation of Leaf Water Status in High- and Low-Mannitol Olive Cultivars

2014

The role of mannitol and malic acid in the regulation of diurnal leaf water relations was investigated in ‘Biancolilla’ (high-mannitol) and ‘Cerasuola’ (low-mannitol) olive trees. Photosynthetic photon flux density (PPFD), vapor pressure deficit (VPD), stomatal conductance (gs), transpiration rate (T), relative water content (RWC), mannitol and malic acid were measured in ‘Biancolilla’ and ‘Cerasuola’ leaves during a dry and hot day of summer in Sicily. In general, leaves of ‘Biancolilla’ trees exhibited greater mannitol content, higher gs and T, but lower RWC than leaves of ‘Cerasuola’ trees. Differences in gs and T between the two cultivars were evident mainly in mid to late morning. ‘Bia…

Effects of reduced irradiance on hydraulic architecture and water relations of two olive clones with different growth potentials

2009

Abstract The hydraulic architecture and water relations of two olive genotypes, ‘Leccino Dwarf’ (LD) and ‘Leccino Minerva’ (LM) growing at two irradiance levels i.e. full sunlight irradiance (HI) and 50% sunlight irradiance (LI) were studied. The two clones showed similar plant hydraulic conductances (Kplant) and similar conductance of roots and leaves (Kroot and Kleaf) when growing at equal irradiance levels. However, both Kplant and Kroot were significantly lower in LI plants than in HI ones. On the contrary, Kleaf was unaffected by the light regime. One-year-old twigs of LI plants produced longer xylem conduits but lower average diameter of conduits and less conduits per unit xylem cross…