Search results for "stomatal conductance"
showing 10 items of 56 documents
Growth and water relations of field-grown ‘Valencia’ orange trees under long-term partial rootzone drying
2017
Climate, soil water potential (SWP), leaf relative water content (RWC), stem water potential (WPstem), stomatal conductance (g s), trunk, shoot and fruit growth of ‘Valencia’ orange trees were monitored during five consecutive seasons (2007–2012) to study water status and growth responses to irrigation placement or volume. 48 adult trees were exposed to conventional irrigation (CI, 100% of crop evapotranspiration on both sides of the rootzone), partial rootzone drying (PRD, 50% of CI water only on one alternated side of the rootzone) and continuous deficit irrigation (DI, 50% of CI water on both sides of the rootzone). Reducing irrigation volumes by 55% (DI) over CI increased leaf water def…
Effect of Gibberellic Acid on Growth, Yield, and Quality of Leaf Lettuce and Rocket Grown in a Floating System
2019
Gibberellins (GAs) are growth hormones strongly involved in a wide variety of physiological activities. Currently, gibberellins are commercially used to enhance phenotypic characteristics, earliness, and productivity of many vegetable and ornamental crops. In this work, the efficacy of supplementation of low levels of gibberellic acid (0, 10&minus
Effects of partial rootzone drying and rootstock vigour on growth and fruit quality of 'Pink Lady' apple trees in Mediterranean environments
2008
We investigated the effects of partial rootzone drying (PRD) and rootstock vigour on water relations, and vegetative and productive performance of ‘Pink Lady’ apple (Malus domestica Borkh.) trees in central Sicily. In a first field trial, trees on MM.106 rootstock were subjected to: Conventional irrigation (CI), maintaining soil moisture above 80% of field capacity; PRD irrigation, where only one alternated side of the rootzone received 50% of the CI irrigation water; and continuous deficit irrigation (DI), where 50% of the CI water was equally applied to both sides of the rootzone. In a second trial, trees on M.9 or MM.106 were subjected to CI and PRD irrigation. PRD reduced stomatal condu…
Arabidopsis mutant dnd2 exhibits increased auxin and abscisic acid content and reduced stomatal conductance
2019
Arabidopsis thaliana cyclic nucleotide-gated ion channel gene 4 (AtCNGC4) loss-of-function mutant dnd2 exhibits elevated accumulation of salicylic acid (SA), dwarfed morphology, reduced hypersensitive response (HR), altered disease resistance and spontaneous lesions on plant leaves. An orthologous barley mutant, nec1, has been reported to over-accumulate indole-3-acetic acid (IAA) and to exhibit changes in stomatal regulation in response to exogenous auxin. Here we show that the Arabidopsis dnd2 over-accumulates both IAA and abscisic acid (ABA) and displays related phenotypic and physiological changes, such as, reduced stomatal size, higher stomatal density and stomatal index. dnd2 showed i…
Sustainability of pistachio production (Pistacia vera L.) under supplemental irrigation in a Mediterranean climate
2018
Abstract The objective of this study was to examine the effects of supplemental micro-irrigation, in a commercial rainfed orchard, on tree water status, gas exchange and productivity of Pistacia vera L. (cv Bianca) grafted on P. terebinthus. Irrigating with 10–15% of estimated full evaporative demand significantly increased average annual productivity by increasing yield in the on-crop year of this alternate bearing species. Irrigation increased yield by 30%, resulting in 1600 kg of in-shell product per ha. Irrigation delayed leaf senescence while flower bud abscission was not reduced until the third year of experiment. Irrigation did not improve gas exchange during Stage I (pericarp growth…
Global uptake of carbonyl sulfide (COS) by terrestrial vegetation: Estimates corrected by deposition velocities normalized to the uptake of carbon di…
2005
Abstract. COS uptake by trees, as observed under dark/light changes and under application of the plant hormone abscisic acid, exhibited a strong correlation with the CO2 assimilation rate and the stomatal conductance. As the uptake of COS occurred exclusively through the stomata we compared experimentally derived and re-evaluated deposition velocities (Vd; related to stomatal conductance) for COS and CO2. We show that Vd of COS is generally significantly larger than that of CO2. We therefore introduced this attribute into a new global estimate of COS fluxes into vegetation. The new global estimate of the COS uptake based on available net primary productivity data (NPP) ranges between 0.69-1…
Drought tolerance of clonal Malus determined from measurements of stomatal conductance and leaf water potential.
2003
We examined tolerance to soil drying in clonally propagated apple (Malus domestica Borkh.) rootstocks used to control shoot growth of grafted scions. We measured leaf conductance to water vapor (g(L)) and leaf water potential (Psi(L)) in a range of potted, greenhouse-grown rootstocks (M9, M26, M27, MM111, AR69-7, AR295-6, AR360-19, AR486-1 and AR628-2) as the water supply was gradually reduced. Irrespective of the amount of available water, rootstocks that promoted scion shoot growth (M26 and MM111) generally had higher g(L) and more negative Psi(L) than rootstocks that restricted scion shoot growth (M27 and M9). After about 37 days of reduced water supply, there were significant decreases …
The effect of saline water on Phillyrea angustifolia L. seedlings
2013
Water limitations in the Mediterranean areas are very common and the use of saline water for plant irrigation is becoming a necessity. Salinity generally affects plant growth and physiological processes, and can eventually lead to leaf injuries and plant death. For these reasons, the selection of salt tolerant species is a priority for landscaping purposes in the Mediterranean areas. The objective of this study was to evaluate the effect of saline water on Phillyrea angustifolia plant performance. Seventy-five rooted cuttings were grown in the greenhouse in 4-liter pots and irrigated for 5 months with saline water at different NaCl concentrations for two consecutive years. In 2010, 45 plant…
Infestation of broad bean (Vicia faba) by the green stink bug (Nezara viridula) decreases shoot abscisic acid contents under well-watered and drought…
2017
The response of broad bean (Vicia faba) plants to water stress alone and in combination with green stink bug (Nezara viridula) infestation was investigated through measurement of: (1) leaf gas exchange; (2) plant hormone titres of abscisic acid (ABA) and its metabolites, and of salicylic acid (SA); and (3) hydrogen peroxide (H2O2) content. Furthermore, we evaluated the effects of experimentally water-stressed broad-bean plants on N. viridula performance in terms of adult host–plant preference, and nymph growth and survival. Water stress significantly reduced both photosynthesis (A) and stomatal conductance (gs), while infestation by the green stink bug had no effects on photosynthesis but s…
Growth, yield and fruit quality of 'Tropic Snow' peach on size-controlling rootstocks under dry Mediterranean climates
2013
Abstract A six-year trial was carried out to evaluate the vegetative and productive performance of low-chill, early-ripening ‘Tropic Snow’ peach grown on five peach × almond rootstocks, different for their vigor. The study was conducted in south-western Sicily using 45 V-trained peach trees planted in 2005 and grafted on GF677, the most common rootstock in Sicily, and four low-vigor rootstocks selected at the Department of Agricultural, Food and Environmental Sciences, University of Pisa, namely IS5/8 (Polluce), IS5/19 (Castore), IS5/23, and IS5/29. Trunk circumference, winter and summer pruning weight, total number and weight of fruits per tree, and major fruit quality traits were recorded…