Search results for "Stem water potential"
showing 10 items of 18 documents
Water Deficit Affects the Growth and Leaf Metabolite Composition of Young Loquat Plants
2020
Water scarcity in the Mediterranean area is very common and understanding responses to drought is important for loquat management and production. The objective of this study was to evaluate the effect of drought on the growth and metabolism of loquat. Ninety two-year-old plants of &lsquo
Soil and Regulated Deficit Irrigation Affect Growth, Yield and Quality of ‘Nero d’Avola’ Grapes in a Semi-Arid Environment
2021
The present work studied the effect of two consecutive years of regulated deficit irrigation (RDI) compared to rain fed management on the vegetative growth, yield, and quality of ‘Nero d’Avola’ grapes. The trial was conducted separately in two soils (vertisol and entisol) located at the top and bottom hillside of the same vineyard. Vertisol was characterized by greater depth, organic matter, exchangeable K20, and total N than entisol. RDI was based on an irrigation volume at 25% of estimated crop evapotranspiration (ETc) up to end of veraison and 10% of estimated ETc up to 15 days before harvest. Predawn water potential (PDWP) was used as indicator of plant water status and irrigation timin…
Water status and gas exchange of pistachio trees under different irrigation levels
2017
The aim of this study was to investigate the physiological responses of pistachio trees to varying water supply in the attempt to identify reliable parameters to manage irrigation. Three different irrigation regimes were applied to 25-year-old pistachio trees of cultivar 'Bianca' on P. terebinthus rootstock. Midday stem water potential (ΨSWP), leaf relative water content (RWC), light-saturated net CO2assimilation (An), stomatal conductance (gs), and ambient conditions were monitored throughout the season, and light response curves of net photosynthesis were constructed. To reflect tree water status, trees were separated into three classes of ΨSWP, no deficit (ΨSWP> -1.5 MPa), mild defici…
Validation of an online system for the continuous monitoring of tree water status for sustainable irrigation managements in olive (Olea europaea L.)
2016
Abstract As a result of climate change a large reduction of agricultural water through improved irrigation management is a major need for agriculture sustainability. To this aim, always more sensitive sensors to monitor plant water status have been developed in recent years. Among them, the leaf patch clamp pressure probes are very promising for water management of olive but until now have been tested only in few environmental and management conditions. In this work these sensors have been tested for two consecutive years on two completely different management systems: a traditional rainfed orchard and a super high density (SHD) drip irrigated orchard. Within the SHD orchard the probes have…
Detecting Mild Water Stress in Olive with Multiple Plant-Based Continuous Sensors.
2021
A comprehensive characterization of water stress is needed for the development of automated irrigation protocols aiming to increase olive orchard environmental and economical sustainability. The main aim of this study is to determine whether a combination of continuous leaf turgor, fruit growth, and sap flow responses improves the detection of mild water stress in two olive cultivars characterized by different responses to water stress. The sensitivity of the tested indicators to mild stress depended on the main mechanisms that each cultivar uses to cope with water deficit. One cultivar showed pronounced day to day changes in leaf turgor and fruit relative growth rate in response to water w…
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…
Predicting soil and plant water status dynamic in olive orchards under different irrigation systems with Hydrus-2D: Model performance and scenario an…
2018
The paper analyzes the performance of Hydrus-2D model to simulate the dynamic of soil water contents and transpiration fluxes in an olive orchard in which two different irrigation systems were used in 2011 and 2012. The relationship between measured midday stem water potential, MSWP, and simulated relative transpiration (ratio between simulated actual and maximum crop transpiration), Ks, was also identified with the aim to use the model for crop water status predictions. Finally, a scenario analysis was carried out for irrigation management purposes, by considering the level of crop water stress achieved in the different phases of the vegetative growth. The results evidenced that active roo…
Recurrent deficit irrigation and fruit harvest affect tree water relations and fruitlet growth in ‘valencia’ orange
2019
Background – Partial rootzone drying is an irrigation strategy known for increasing water use efficiency without significantly affecting tree water status. ‘Valencia’ oranges have a very long development period and nearly mature fruit and new fruitlets may be present at the same time on the tree, competing for water and assimilates. Objectives – The present study investigates the effect of recurrent deficit irrigation and fruit harvest on tree water status and fruitlet growth of ‘Valencia’ orange. Methods – Forty-eight adult trees were exposed to three irrigation treatments for seven years (2007–2013): irrigation with 100% of ETc (CI), continuous deficit irrigation (DI, 50% of CI) and parti…
Improvement of FAO-56 Model to Estimate Transpiration Fluxes of Drought Tolerant Crops under Soil Water Deficit: Application for Olive Groves
2014
[EN] Agro-hydrological models are considered an economic and simple tool for quantifying crop water requirements. In the last two decades, agro-hydrological physically based models have been developed to simulate mass and energy exchange processes in the soil-plant-atmosphere system. Although very reliable, because of the high number of required variables, simplified models have been proposed to quantify crop water consumes. The main aim of this paper is to propose an amendment of the Food and Agricultural Organization (FAO) of the United Nations FAO-56 spreadsheet program to introduce a more realistic shape of the stress function, valid for mature olive orchards (Olea europaea L.). The mod…
Using field measurements and FAO-56 model to assess the eco-physiological response of citrus orchards under regulated deficit irrigation
2017
[EN] Micro-irrigation is considered one of the most efficient water distribution systems and allows increasing water use efficiency if coupled with effective water-saving irrigation management strategies as regulated deficit irrigation (RDI) or partial root-zone drying (PRD) techniques. However, application of these strategies makes it crucial the real-time monitoring of soil and crop water status, in order to identify appropriate irrigation scheduling parameters (irrigation timing and doses) and to prevent irreversible damage of plant system and/or crop yield reductions. Even if midday stem water potential (MSWP) is considered one of the most affordable indicator for direct determinations …