Search results for "Water potential"

Relationship between tree water status and physiology, yield, and fruit quality in the table olive (Olea europaea sativa L.) cultivar ‘Nocellara del …

2012

Although the olive (Olea europaea sativa l.) is considered a xerophytic species, long periods of water stress and high temperatures during summer months can greatly affect plant physiology and productivity. In recent years, the use of plant-based water status indicators have become popular in the study of plant-water relationships and in the design of irrigation programs, particularly midday stem water potential (ψstem). The current trend in the irrigation of olive trees is in the development of Deficit Irrigation (DI) systems whereby the water is applied at a rate which is lower than evapotranspiration needs, resulting in only very small reductions in yield. Rather than working towards min…

Plant-based water stress sensing in two olive cultivars with different physiological responses to drought

2022

A large portion of modern olive plantings is dominated by one main cultivar (‘Arbequina’) planted at super high density (SHD, 1,500 tree ha‑1), leading to a dangerous reduction in olive biodiversity. Very few cultivars have growth and productive patterns that suit the SHD system requirements. Partial intensification and mechanization with several cultivars may represent the safest and easiest alternative. The efficient use of limited natural resources, such as water, in SHD systems, requires precise management. Continuous plant-based sensing is a promising approach to managing water, mainly tested on the cultivar ‘Arbequina’. In this study, we evaluated the sensitivity of two promising indi…

Modeling olive ecophysiological response to soil water deficit.

2011

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…

Leaf water relation traits in typical Sicilian varieties of Vitis vinifera L.

2014

In Italy, grapevines are extensively cultivated, with Sicily representing one of the most significant wine regions. The high number of autochthonous grapevine varieties represents an important source of genetic diversity, and the many Sicilian varieties have anatomical and physiological traits that allow them to resist to different levels of drought stress. We investigated the water relation parameters of four cultivars of Vitis vinifera L. (Catarratto, Corinto, Nero d'Avola and Zibibbo) and characterized their leaf hydraulics. Measurements were conducted during summer on plants growing in the experimental field of the IBBR-CNR near Palermo. Daily patterns of leaf water potential (Yleaf) an…

In Situ X-Ray Tomography Imaging of Soil Water and Cyanobacteria From Biological Soil Crusts Undergoing Desiccation

2018

Biological soil crusts (biocrusts) are millimeter-sized microbial communities developing on the topsoils of arid lands that cover some 12% of Earth’s continental area. Biocrusts consist of an assemblage of mineral soil particles consolidated into a crust by microbial organic polymeric substances that are mainly produced by the filamentous bundle-forming cyanobacteria, among which Microcoleus vaginatus is perhaps the most widespread. This cyanobacterium is the primary producer for, and main architect of biocrusts in many arid soils, sustaining the development of a diverse microbial community. Biocrusts are only active when wet, and spend most of their time in a state of desiccated quiescence…

Is rootstock-induced dwarfing in olive an effect of reduced plant hydraulic efficiency?

2006

We investigated the hydraulic architecture of young olive trees either self-rooted or grafted on rootstocks with contrasting size-controlling potential. Clones of Olea europea L. (Olive) cv ''Leccino'' inducing vigorous scion growth (Leccino ''Minerva'', LM) or scion dwarfing (Leccino ''Dwarf'', LD) were studied in different scion/rootstock combinations (LD, LM, LD/LD, LM/LM, LD/LM and LM/LD). Shoots growing on LD root systems developed about 50% less leaf surface area than shoots growing on LM root systems. Root systems accounted for 60-70% of plant hydraulic resistance (R), whereas hydraulic resistance of the graft union was negligible. Hydraulic conductance (K = 1/R) of LD root systems w…

Gravity-Driven Infiltration and Subsidence Phenomena in Posidonia oceanica Residues

2019

A simplified infiltration model for highly permeable porous media was introduced, assuming the matric potential gradient as negligible compared to the gravitational gradient. This model enabled us to determine the delay time, i.e., the time that the water front takes (from the beginning of rainfall) to reach the bottom of the highly permeable layer. Posidonia oceanica (Linnaeus) Delile residues were used as a porous media, in order to study the infiltration process that provides salt leaching under natural rainfall when these residues are arranged in a storage area, before reusing. By using a laboratory rainfall simulator, delay times were measured to verify the applicability of the aforeme…

The Effect of Plant Water Status on the Chemical Composition of Pistachio Nuts (Pistacia vera L. Cultivar Bianca)

2020

Pistachio nuts are worldwide appreciated for their chemical and organoleptic profiles. There are several studies on the influence of irrigation on pistachio productivity, whereas there are little available data on the influence on nut quality. In this study we characterized some qualitative traits of pistachio nuts cultivar Bianca in Mediterranean environment and how plant water status affected them. Water status had a positive and significant influence on the chlorophylls content, nuts from less stressed trees showed higher values of chlorophyll a (14.7 mg/100 g) and b (21.1 mg/100 g) compared than more stressed trees (9.3 and 11.5 mg/100 g for a and b, respectively). Solid phase microextr…

Response of transgenic mannitol-producing tobacco plants to water deficit

2008

Transgenic mannitol-producing (+mtlD) and wild type (-mtlD) tobacco plants were exposed to water deficit to test whether mannitol is involved in drought stress protection. Rooted cuttings of -mtlD and +mtlD plants were fully irrigated (100% ET) or received 25% ET for 40 days, followed by 20 days of re-watering. Water deficit reduced RWC of both plant types starting on the 22nd day, total stem length of -mtlD 25% ET already after 11 days, whereas that of +mtlD 25% ET only after 34 days. After 30 days of deficit, a greater percentage of mature foliage was retained by +mtlD 25% ET compared to -mtlD 25% ET. Mannitol-1-phosphate dehydrogenase activity of +mtlD plants was not affected by water de…