Search results for "use efficiency"
showing 10 items of 54 documents
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
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…
S-34 and N-15 labelling to model S and N flux in plants and determine the different components of N and S use efficiency
2013
International audience; In order to highlight our understanding on ecosystems functioning and resource sharing/competition, either in artificial environment or agrosystems, according to changes in the climatic conditions, it is necessary to measure accurately element fluxes within plants. Stable isotopes allow tracking safely and accurately on a short time frame the behavior of elements in plants. After a short review devoted to isotopic studies of elemental flux within plants, we explain how a direct multiple labelling study might be conducted in a plant, so as to measure over short time nitrogen and sulfur acquisition, and assimilates arising from a labelled source.
Effect of Mycorrhizal Inoculation on Melon Plants under Deficit Irrigation Regimes
2023
The shortage of good quantity and quality of water for irrigated agriculture is a major problem in arid and semiarid regions. To deal with this problem, deficit irrigation (DI) or arbuscular mycorrhizal fungi (AMF) inoculation have been proposed and adopted for many crops as a tool to save water, or to improve crop tolerance to drought stress. An experiment was conducted for two consecutive years to evaluate the effect of mycorrhizal inoculation on the physiological, morphological, yield, and quality characteristics of melon plants grown under deficit irrigation. Melon crop (Cucumis melo L. cv. Helios) was grown under field conditions adopting a split-plot design with four replications, whe…
Cover crop management and water conservation in vineyard and olive orchards
2021
Abstract Sustainability in orchard crops is an important goal for farmers, decision-makers and consumers. The United Nations Sustainable Development Goals emphasize the importance of the soils in the Earth System to achieve sustainability and accomplish the Land Degradation Neutrality Challenge. Within the world agriculture land, olive and vineyards are within the eldest crops in the world, and they are also the ones with the highest degree of soil degradation. Cover crops (CC) are widely accepted as sustainable crop management that reduces soil and water losses, restores organic matter, increases biodiversity and fertility in degraded agriculture soils. The agriculture land must shift into…
Using HYDRUS-2D model to assess the optimal drip lateral depth for eggplant crop in a sandy loam soil of central Tunisia
2016
The main objective of the work is to assess the optimal drip lateral depth for Eggplant crop (Solanum melongena L.) irrigated with a drip system in a sandy loam soil by means of field measurements and simulation models. Initially, the performance of Hydrus-2D was assessed based on the comparison between simulated soil water contents (SWC) and the corresponding measured in two plots, in which laterals with co-extruded emitters were laid on the soil surface (drip irrigation, DI-0) and at 20 cm depth (subsurface drip irrigation, SDI-20), respectively. In order to identify the optimal position of the lateral, the results of different scenarios, obtained by changing the installation depth of the…
Ecklonia maxima-derivate seaweed extract supply as mitigation strategy to alleviate drought stress in chicory plants
2023
Extreme climatic conditions have a severe repercussion on agriculture and on food availability. Ecological means to overcome drought are important to improve agroecosystems sustainability and resilience. The use of an Ecklonia maxima-derivate seaweed extract (SwE) as a tool to mitigate drought constrain in chicory plants grown in greenhouse was evaluated. Plants were cultivated in plastic pots filled with peat and subjected to drought stress by retaining moisture range at 90–100% of water holding capacity (WHC) [well-watered (WW)], 60–70% WHC [moderate drought stress (MDS)] or 30–40% WHC [severe drought stress (SDS)]. Drought stress decreased plant growth traits and yield. However, in plant…
Sexes in gynodioeciousGeranium sylvaticumdo not differ in their isotopic signature or photosynthetic capacity
2017
• In gynodioecious plants, females are expected to produce more or better seeds than hermaphrodites in order to be maintained within the same population. Even though rarely measured, higher seed production can be achieved through differences in physiology. • In this work, we measured sexual dimorphism in several physiological traits in the gynodioecious plant Geranium sylvaticum. Photosynthetic rate, stomatal conductivity, transpiration rate, water use efficiency and isotopic signatures were measured in plants growing in two habitats differing in light availability. • Females have been reported to produce more seeds than hermaphrodites. However, we did not observe any significant difference…
Diurnal and Seasonal Solar Induced Chlorophyll Fluorescence and Photosynthesis in a Boreal Scots Pine Canopy
2019
Solar induced chlorophyll fluorescence has been shown to be increasingly an useful proxy for the estimation of gross primary productivity (GPP), at a range of spatial scales. Here, we explore the seasonality in a continuous time series of canopy solar induced fluorescence (hereafter SiF) and its relation to canopy gross primary production (GPP), canopy light use efficiency (LUE), and direct estimates of leaf level photochemical efficiency in an evergreen canopy. SiF was calculated using infilling in two bands from the incoming and reflected radiance using a pair of Ocean Optics USB2000+ spectrometers operated in a dual field of view mode, sampling at a 30 min time step using custom written …
Determination of Evapotranspiration and Annual Biomass Productivity of a Cactus Pear [Opuntia ficus-indica L. (Mill.)] Orchard in a Semiarid Environm…
2013
A micrometeorological approach based on the surface energy balance was adopted to estimate evapotranspiration fluxes and crop coefficient data from an irrigated cactus pear [Opuntia ficus-indica L. (Mill.)] orchard under Mediterranean climatic conditions. Highfrequency temperature readings were taken above the canopy top to get sensible heat flux values (HSR) using the surface renewal technique. These values were compared against eddy covariance sensible heat fluxes (HEC) for calibration. Latent heat flux (or evapotranspiration, ET) was obtained by solving the daily energy balance equation. Measurements of soil hydraulic components were integrated with the analysis of the surface energy flu…