Search results for "leaf"

Hyperspectral response of agronomic variables to background optical variability: Results of a numerical experiment

2022

Understanding how biophysical and biochemical variables contribute to the spectral characteristics of vegetation canopies is critical for their monitoring. Quantifying these contributions, however, remains difficult due to extraneous factors such as the spectral variability of canopy background materials, including soil/crop-residue moisture, soil-type, and non-photosynthetic vegetation (NPV). This study focused on exploring the spectral response of two important agronomic variables (1) leaf chlorophyll content (Cab ) and (2) leaf area index (LAI) under various canopy backgrounds through a global sensitivity analysis of wheat-like canopy spectra simulated using the physically-based PROSAIL …

Effect of single-species and mixed-species leaf leachate on bacterial communities in biofilms

2009

Dissolved organic matter in the form of leaf leachate represents an important carbon and energy source in many lotic ecosystems. In this study, we investigated utilization of mono-specific and mixed-species leaf leachate and impacts on biofilm bacterial community structure. Ceramic tiles were incubated in a Northeast Ohio stream to allow for biofilm development and then exposed in the laboratory to glucose or leachate from: sugar maple (Acer saccharum), pin oak (Quercus palustris), maple oak, American beech (Fagus grandifolia), witch hazel (Hamamelis virginiana), or beech witch hazel. Bacterial responses to these amendments were compared to un-amended controls based on fluorescent in situ h…

Effect of Nitrogen Fertilization on the Quality of Swiss Chard at Harvest and during Storage as Minimally Processed Produce

2014

The effects of different levels of nitrogen fertilization (0-50-100-150-200 kg ha-1), minimal processing and cold storage (14 days at 4°C) on yield and quality of fresh-cut Swiss Chard (Beta vulgaris L. var. cicla L.) were evaluated. Increasing the level of nitrogen fertilization over 100 kg N ha-1, plants had a higher fresh weight, reduced their dry matter content and resulted taller and leafier. Total and marketable yield increased linearly as increasing nitrogen level. Both nitrate and ascorbic acid content at harvest increased as increasing nitrogen supply. Nitrogen fertilization negatively affected the yield of minimal processing. No effect on appearance and quality loss during cold st…

Global Scale IB AMSR2 Vegetation Optical Depth at X-Band

2021

Vegetation Optical Depth (VOD) plays an increasingly important role in studying global carbon, water and energy transformation [1], [2]. This study explores the performance of the X-MEB (X-band microwave emission of the biosphere) model at global scale. Similar to the L-MEB model, the X-MEB model, built by INRAE (Institut national de recherche pour l'agriculture, l'alimentation et l'environnement) Bordeaux, aims to retrieve VOD (referred to as IB X-VOD) at X-band. To avoid the ill-posed problem caused by retrieving two parameters of interest (soil moisture (SM) and VOD) from mono-angular and dual-polarized observations (AMSR2), which are strongly correlated, we used the ERA5 SM product as a…

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…

Role of Languages in Consumers' Food Description: Contrasting Malagasy and French Descriptors of M oringa oleifera Leaf Powder

2015

Vegetation growth parameters and leaf temperature: Experimental results from a six plots green roofs' system

2016

Abstract The paper provides a contribution for populating database of three physical parameters needed to model energy performance of buildings with green roofs: “coverage ratio” ( σ f ), leaf area index (LAI) and leaf temperature ( T f ). On purpose, six plant species were investigated experimentally: Phyla nordiflora, Aptenia lancifolia , Mesembryanthenum barbatus , Gazania nivea, Gazania uniflora , and Sedum . Proper ranges of the cited parameters have been found for each species. The here indicated ranges of σ f values refer to different growth levels of the species in the same lapse of time, that is four months. Single measured LAI values are also reported for the same plants. As for t…

Prospero hierae (Hyacinthaceae), a New Species from Marettimo Island (Sicily)

2009

A new species, Prospero hierae C. Brullo, S. Brullo, Giusso, Pavone & Salmeri (Hyacinthaceae), from Island of Marettimo (Egadi Archipelago, Sicily) is described and illustrated. Its chromosome number (2n = 14), leaf anatomy and ecology are examined. This small species with glaucous, adaxially flat leaves is closely related with the taxa belonging to the Prospero autumnale group and, in particular, it shows more affinities with P. corsicum, P. pulchellum and P. minimum.

EcFLO, a FLORICAULA-like gene from Eschscholzia californica is expressed during organogenesis at the vegetative shoot apex.

2003

FLORICAULA/ LEAFY-like genes were initially characterized as flower meristem identity genes. In a range of angiosperms, expression occurs also in vegetative shoot apices and developing leaves, and in some species with dissected leaves expression is perpetuated during organogenesis at the leaf marginal blastozone. The evolution of these expression patterns and associated functions is not well understood. We have isolated and characterized a FLORICAULA-like gene from California Poppy, Eschscholzia californica Cham. (Papaveraceae), a species belonging to the basal eudicot clade Ranunculales. EcFLO encodes a putative 416-amino-acid protein with highest similarity to homologous genes from Trocho…

Two new natural begomovirus recombinants associated with the tomato yellow leaf curl disease co-exist with parental viruses in tomato epidemics in It…

2009

Two tomato geminivirus species co-exist in protected crops in Sicily, Tomato yellow leaf curl Sardinia virus (TYLCSV, found in 1989) and Tomato yellow leaf curl virus (TYLCV, found in 2002), and mixed infections have been detected. In a field survey conducted in 2004, the viral intergenic region (IR) was amplified from infected plants, and molecules apparently hybrid between the two species were found, but only in plants where one or both parental species were also present. Two of these hybrids, named 2/2 and 2/5, were isolated and infectious clones were obtained. They were both readily whitefly-transmitted to tomato plants; clone 2/5 produced symptoms typical of TYLCSV and TYLCV, while clo…