Search results for "botany"
showing 10 items of 4586 documents
Phenological model performance to warmer conditions: application to Pinot noir in Burgundy.
2014
<p style="text-align: justify;"><strong>Aim</strong>: The current work aims to assess the performance of two phenological models - a linear model (<em>Grapevine Flowering</em> <em>Véraison</em> model, <em>GFV</em>) and a curvilinear model (<em>Wang and</em> <em>Engel</em> model, <em>WE</em>) - to warmer temperature conditions for the grapevine variety Pinot noir in Burgundy.</p><p style="text-align: justify;"><strong>Methods and results</strong>: Simulations using historical data from the 1973-2005 period were similar between models and consistent with observations. To mimic pot…
Effect of incorporation of Brassica napus L. residues in soils on mycorrhizal fungus colonisation of roots and phosphorus uptake by maize (Zea mays L…
2007
International audience; Plants in the Brassicaceae family are known to contain thioglucoside compounds that produce isothiocyanates when tissues are disrupted. These chemicals have a negative effect on soil-borne fungal pathogens, and possibly on vesicular-arbuscular mycorrhizal (AM) fungi. We investigated the effect of incorporation of Brassica napus L. residues in a soil on mycorrhizal colonisation of roots, P uptake and growth of following maize (Zea mays L.) crop. A pot experiment was carried out in a glasshouse with pre-inoculation with Glomus intraradices (+I and -I), incorporation of B. napus L. residues (+R and -R) and mineral P fertilization (+P and -P) as studied factors. The soil…
Morphology and yield response to weed pressure by corn hybrids differing in canopy architecture
2001
Abstract Recently, corn ( Zea mays L.) hybrids accumulating more leaf area above the ear, maturing earlier, yielding better in narrower row spacings and tolerating higher population densities than conventional hybrids have been developed. However, no research has been conducted to assess their ability to compete with weeds. The objective of this study was to quantify morphological and grain yield responses of hybrids with differing canopy architectures to the presence and absence of weeds. Field experiments were conducted in 1996, 1997, and 1998 at Ste. Anne de Bellevue, Quebec and in 1996 at Ottawa, Ontario. Three hybrids, leafy reduced-stature (LRS), late maturing big leaf (LMBL), and con…
Dependence of seed nitrogen concentration on plant nitrogen availability during the seed filling in pea
1999
Abstract The final seed nitrogen (N) concentration of the pea ( Pisum sativum L.) varies greatly with environment. These variations seem to be related to N availability in the plant. To understand such an effect, the pattern of seed N concentration during seed filling was analysed at a given node as the ratio of seed N accumulation rate and seed dry matter accumulation rate. Three experiments were conducted in the field and glasshouse. Pea genotypes ‘Solara’, ‘Frisson’ and its non-nodulating mutant ‘P2’ were grown and different treatments were applied to manipulate N availability during seed filling. Treatments included N supply (addition of N fertiliser), depodding (removal of pods) and de…
: J. Sci. Food Agric.
2017
Background: The measurement of carbon isotopic discrimination in grape sugars at harvest (δ13 C) is an integrated assessment of water status during ripening. It is an efficient alternative to assess variability in the field and discriminate between management zones in precision viticulture, but further work is needed to completely understand the signal.; Results: This work, spanning over 3 years, performed in a hillslope toposequence in Burgundy, delineates the relationships between main soil properties (gravel amount, slope, texture) and the grapevine water status assessed by δ13 C. The highest δ13 C, indicating most severe water deficit, was recorded in gravelly soils on steep slopes. The…
Contamination of rapeseed harvest by volunteers of other varieties : a study of intergenotypic competition
2004
Rapeseed volunteers in rapeseed crops can cause contamination in harvest through pollen and seeds. The aim of the study was to predict pollen and seed production by volunteers in winter rapeseed crops according to the genotypes of the crop and the volunteers. Firstly an experimental analysis of intraspecific competition was carried out in 2000 and 2001 on two and six genotypes, respectively. The main competition period begins with vegetation onset and affects pollen and seed production of the volunteers. Relations between density, height, yield and number of flowers were developed based on results from experiments and literature. Knowing the densities and heights of volunteers and crop on t…
Assessing non-chemical weeding strategies through mechanistic modelling of blackgrass (Alopecurus myosuroides Huds.) dynamics
2010
; Because of environmental and health safety issues, it is necessary to develop strategies that do not rely on herbicides to manage weeds. Introducing temporary grassland into annual crop rotations and mechanical weeding are the two main features that are frequently used in integrated and organic cropping systems for this purpose. To evaluate the contribution of these two factors in interaction with other cropping system components and environmental conditions, the present study updated an existing biophysical model (i.e. AlomySys) that quantifies the effects of cropping system on weed dynamics. Based on previous experiments, new sub-models were built to describe the effects on plant survi…
Microalgae community structure analysis based on 18S rDNA amplification from DNA extracted directly from soil as a potential soil bioindicator
2005
International audience; Soil algae are photosynthetically active microorganisms showing changeable community structure, depending on the soil type, the agricultural practices and the application of pesticides. To characterise algal community structure, molecular approaches complementary to classical microbiological approaches based on the isolation and the culture of soil algae are required. Our study describes a polymerase chain reaction (PCR) approach targeting algal 18S rDNA sequences of desoxyribonucleic acid (DNA) samples extracted either from unialgal eukaryotic microalgae culture, complex assemblages of microalgae populations or natural soil communities. Our first results showed that…
The membrane proteome of Medicago truncatula roots displays qualitative and quantitative changes in response to arbuscular mycorrhizal symbiosis
2014
International audience; Arbuscular mycorrhizal (AM) symbiosis that associates roots of most land plants with soil-borne fungi (Glomeromycota), is characterized by reciprocal nutritional benefits. Fungal colonization of plant roots induces massive changes in cortical cells where the fungus differentiates an arbuscule, which drives proliferation of the plasma membrane. Despite the recognized importance of membrane proteins in sustaining AM symbiosis, the root microsomal proteome elicited upon mycorrhiza still remains to be explored. In this study, we first examined the qualitative composition of the root membrane proteome of Medicago truncatula after microsome enrichment and subsequent in dep…
Effect of growing area on tocopherols, carotenoids and fatty acid composition ofPistacia lentiscusedible oil
2014
International audience; In this investigation, we aim to study, for the first time, the effect of the growing area on tocopherols, carotenoids and fatty acid content of Pistacia lentiscus fixed oil. Fruits were harvested from eight different sites located in the north and the centre of Tunisia. Tocopherols, carotenoids and fatty acid content of the fixed oils were determined. The highest carotenoid content was exhibited by Feija oil (10.57 mg/kg of oil). Oueslatia and Tabarka oils displayed the highest alpha-tocopherol content (96.79 and 92.79 mg/kg of oil, respectively). Three major fatty acids were determined: oleic, palmitic and linoleic acids. Oleic acid was the main fatty acid presenti…