Search results for "Water statu"
showing 10 items of 15 documents
Effects of Three Irrigation Strategies on Gas Exchange Relationships, Plant Water Status, Yield Components and Water Productivity on Grafted Carménèr…
2018
In the Chilean viticultural industry, Carménère is considered an emblematic cultivar that is cultivated mainly in arid and semi-arid zones. For this reason, it is necessary to use precise irrigation scheduling for improving water use efficiency (WUE), water productivity (WP), yield and wine quality. This study evaluated the effects of three deficit irrigation strategies on gas exchange variables, WUE, WP and yield components in a drip-irrigated Carménère vineyard growing under semi-arid climatic conditions during two consecutive seasons (2011/12 and 2012/13). The irrigation strategies were applied in completely randomized design from fruit set (S) to harvest (H). The first irrigation strate…
Gas Exchanges and Stem Water Potential Define Stress Thresholds for Efficient Irrigation Management in Olive (Olea europea L.)
2018
With climate change and decreased water supplies, interest in irrigation scheduling based on plant water status is increasing. Stem water potential (ΨSWP) thresholds for irrigation scheduling in olive have been proposed, however, a physiologically-based evaluation of their reliability is needed. A large dataset collected at variable environmental conditions, growing systems, and genotypes was used to characterize the relation between ΨSWP and gas exchanges for olive. Based on the effect of drought stress on the ecophysiological parameters monitored, we described three levels of stress: no stress (ΨSWP above about −2 MPa), where the high variability of stomatal conductance (gs) suggests a ti…
Cladode growth dynamics in Opuntia ficus-indica under drought
2016
Abstract Cactus pear (Opuntia ficus-indica L. Miller) is a CAM plant with an extraordinary capacity to store water in its succulent stems (cladodes). However, the daily variations of cladode thickness is unknown. Studying cladode thickness fluctuations may be useful for the early prediction of plant dehydration stress. The objective of this study was to determine if age, water availability and temperature influence diel cladode shrinkage and enlargement dynamics in cactus pear. The experiment was conducted in a greenhouse from April to July 2014, using cactus pear plants, equally split into irrigated and unirrigated treatments, and unrooted cladodes detached from mother plants. Soil moistur…
Hierarchy of factors impacting grape berry mass: separation of direct and indirect effects on major berry metabolites
2018
Final berry mass, a major quality factor in wine production, is determined by the integrated effect of biotic and abiotic factors that can also influence berry composition. Under field conditions, interactions between these factors complicate study of the variability of berry mass and composition. Depending on the observation scale, the hierarchy of the impact degree of these factors can vary. The present work examines the simultaneous effects of the major factors influencing berry mass and composition to create a hierarchy by impact degree. A second objective was to separate the possible direct effects of factors on berry composition from an indirect effect mediated through their impact on…
Detecting crop water status in mature olive orchards using vegetation spectral measurements.
2014
Full spectral measurements (350–2500 nm) at tree canopy and leaf levels and the corresponding leaf water potentials (LWP) were acquired in an olive grove of Sicily, at different hours of the day, during summer season 2011. The main objective of the work was to assess, on the basis of the experimental data-set, two different approaches to detect crop water status in terms of LWP. Specifically, using existing families of Vegetation Indices (VIs) and applying Partial Least Squares Regression (PLSR) were optimised and tested. The results indicated that a satisfactory estimation of LWP at tree canopy and leaf levels can be obtained using vegetation indices based on the near infrared–shortwave in…
Assessing different methodologies for irrigation scheduling in protected environment: a case study of green bell pepper
2022
This research aimed at assessing four different methodologies to estimate daily irrigation depth, based on the monitoring of soil water status (soil water content sensors, SWS, and tensiometers, TS) and atmospheric evaporative demand (weighing lysimeter, WL, and Piché evaporimeter, PE), of green bell pepper Capsicum annum L.) cultivated in a greenhouse. Furthermore, two different strategies to apply the daily irrigation depths, i.e., single watering (at 8:00 a.m.) or split into two equal applications (at 8:00 a.m. and at 4:30 p.m.), were also investigated. The experiment was conducted in a completely randomized design and according to a 4 × 2 factorial scheme with eight replications. The st…
Assessment of yield and water productivity of clementine trees under surface and subsurface drip irrigation
2018
Abstract Irrigation systems aimed to optimize water use efficiency in agriculture have become essential due to the increasing water limitations that agriculture is currently facing. Assessment of crop responses to different irrigation systems and strategies are therefore encouraged to find the most efficient options for each specific case. The main objective of this study was to assess the performance of a citrus crop under a surface (SI) and subsurface drip irrigation (SSI) with 7 (SI7, SSI7) or 14 emitters (SI14, SSI14) per plant, as well as a third SS treatment (SSIA), identical to SSI7 but equipped with and additional drip line buried between the tree rows. Evaluations were made in term…
Effects of Saline and Deficit Irrigation on Soil-Plant Water Status and Potato Crop Yield under the Semiarid Climate of Tunisia
2019
Water supplies have been decreasing in several semi-arid regions, and it is therefore necessary to adopt irrigation strategies aimed at maximizing water use efficiency. In this paper, the effects of saline and deficit irrigation on water use efficiency and on potato crop response, based on observations of soil and plant water status, were investigated. Experiments were carried out in Central Tunisia, by monitoring potato crop growth during two seasons in four distinct treatments (T1&ndash
Verifica dell’applicabilità del metodo irriguo sub-superficiale su colture agrumicole e ottimizzazione dell’uso della risorsa idrica
2020
Gli impianti di subirrigazione (SDI), in relazione alla posizione interrata dei gocciolatori permettono la riduzione dei consumi irrigui, garantendo la possibilità di utilizzo di risorse altrimenti non utilizzabili. Tuttavia, i costi di investimento iniziali risultano maggiori di quelli relativi ai tradizionali impianti di microirrigazione e pertanto, diventano economicamente vantaggiosi, se l'efficienza del sistema viene garantita per periodi di almeno 15-20 anni. La SDI, inoltre, permette di ottenere valori elevati di efficienza d’uso dell’acqua, spesso superiori al 90%, se associata ad un monitoraggio continuo dello stato idrico del suolo e della pianta e ad una corretta stima delle esig…
Water status modelling : impact of local rainfall variability in Burgundy (France)
2016
6 pages; International audience; Water status is a key factor in vine development and berry ripening. Water status is strongly affected byenvironmental parameters such as soil and climate. Whereas at local scale the soil variability is frequentlyaccounted for, little scientific reports are available concerning the impact of local rainfall variability ongrapevine water status. In order to accurately register the space and time variations of rainfall at local scale, adense rain-gauges network has been installed in Burgundy. It is composed of 45 rain-gauges over a 28 km² area.Rainfall data collected by each rain-gauge in 2014 and 2015 was used as input variables in the grapevine waterbalance m…