Search results for "DEFICIT IRRIGATION"
showing 10 items of 40 documents
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…
Responses of apple to partial root-zone drying. A review.
2013
Partial root-zone drying (PRD) is a relatively recent strategy aiming at substantial reduction of irrigation volume. It consists of the alternate irrigation of one portion of the root-zone with volumes reduced to about 40-50% of conventional water. PRD is based on the ability of roots in drying soil to produce hormonal signals, like abscissic acid (ABA), responsible for partial stomatal closure. In turn, partial stomatal closure would improve water use efficiency and increase fruit yield per unit of irrigation water. This technique has been tested on a number of fruit crops, including apple. In addition to climatic conditions, which mainly affect atmospheric water demand, soil properties an…
Agro-hydrological models and field measurements to assess the water status of a citrus orchard irrigated with micro-sprinkler and subsurface drip sys…
2021
Compared to the micro-sprinkler irrigation, traditionally used in citrus orchards, subsurface drip systems (SDS) allow increasing the water use efficiency (WUE); when coupled with water-saving strategies, like regulated deficit irrigation (RDI), further increase of WUE are possible. Combining measurements of soil water content (SWC) and weather data with measurements of midday stem water potential (MSWP) makes it possible to identify irrigation scheduling parameters for the RDI. However, measurements of MSWP are destructive and time-consuming, and also require skilled operators. For all these reasons, the use of the agro-hydrological models, such as the FAO-56 model, can be considered a sur…
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…
Implementing a cyber-physical system to monitor soil water status and environmental variables for irrigation scheduling
2018
The most advanced research on irrigation at farm scale, following the paradigm “more crop per drop”, has been aimed at the definition of strategies of precision irrigation, in order to optimize crop water productivity and to maximize the economic benefits without affecting environmental quality.Water saving management strategies, such as regulated deficit irrigation (RDI), can be effectively applied if supported by the real time control of soil/plant water status allowing the identification of appropriate irrigation scheduling parameters (irrigation timing and doses). This challenge can be achieved by integrating sensing technologies, internet of things and cloud computing supported with co…
Identifying the threshold of soil water content for the precise irrigation scheduling of a Citrus orchard under subsurface drip irrigation
2019
Proper irrigation scheduling requires the knowledge of the soil-plant-atmosphere system, including the relationships existing between its various components. During the last decade, the monitoring of soil water content (SWC) has been considered a standard way to determine when crops need to be irrigated. However, under drip irrigation systems in which laterals are laid on the soil surface or buried at a certain depth, the gradients of soil water content are rather high and therefore the threshold of SWC below which crop water stress occurs should account for the position of the sensors; the threshold, in fact, depends on the specific crop system, as well as on the relative position of the m…
Deficit irrigation does not affect alternate bearing of ‘Valencia’ orange trees
2018
This study evaluated the effect of long-term partial rootzone drying and continuous deficit irrigation on the degree of alternate bearing of adult ‘Valencia’ orange trees grown in northern Sicily. Three irrigation strategies were imposed in summer from 2007 to 2011: irrigation with volumes corresponding to 100% of crop evapotranspiration applied to entire rootzone (CI), partial rootzone drying (PRD) with 50% of CI water applied to one alternated side of the rootzone, and continuous deficit irrigation (CDI) with 50% of CI water applied to both sides of the rootzone. The experiment was conducted on 48 adult orange trees arranged according to a randomized block design. Weather and soil paramet…
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…
The effect of different vigour olive clones on growth, dry matter partitioning and gas exchange under water deficit
2012
Abstract In the last decade, high-density olive planting systems have been developed to facilitate less costly mechanical harvesting and pruning by using straddle harvesters. High-density orchards allow faster production since the first crop of fruit starts a few years after planting. In high-density orchards the control of tree size is essential. It is possible to control the vigour and size of the tree by selecting suitable cultivars, by choosing rootstocks capable of controlling scion vigour and, finally, by applying deficit irrigation to reduce plant vegetative growth. Knowledge of tree water requirements is needed for precise irrigation scheduling. In this study, the dwarfing capacity …
Detección de estrés hídrico en olivar mediante datos hiperespectrales y térmicos del sensor AHS
2005
En: XI Congreso Nacional de Teledetección, Teledetección, Avances en la Observación de la Tierra, M. Arbelo, A. González, J.C. Pérez (Eds.), pág.: 53-56, Tenerife, 21-23/9/2005.