Search results for "Germination"
showing 10 items of 251 documents
Studi preliminari sulla propagazione gamica e vegetativa di Hypericum perforatum in ambiente mediterraneo
2014
La conoscenza dei fattori che influenzano la propagazione di una specie rappresenta un passo cruciale nella messa a punto di strategie per la sua moltiplicazione di massa e introduzione in coltura, sia in campo che in ambiente controllato. Sono stati approfonditi alcuni aspetti della propagazione gamica di Hypericum perforatum (di cui è nota la bassa germinabilità del seme), verificando in particolare gli effetti di variabili diverse (soddisfacimento delle esigenze in freddo, temperatura, substrato, presenza di PGPR, batteri promotori della crescita). Sono stati inoltre approfonditi gli studi sulle potenzialità di moltiplicazione vegetativa della specie, da proporre come possibile alternati…
Assessment of antifungal activity of extracts from nettle (Urtica dioica L.) against Alternaria solani = Ocena aktywności przeciwgrzybowej ekstraktów…
2015
(Urtica dioica L.) w stężeniach 2,5, 5,0, 10,0, 20,0, 40,0% wobec fitopatogennego szczepu Alternaria solani. Aktywność przeciwgrzybową ekstraktów z pokrzywy określono w oparciu o indeks tempa wzrostu grzybni oraz indeks kiełkowania zarodników. W badaniach określono również wpływ metod sterylizacji testowanych wyciągów na ich aktywność. Na podstawie uzyskanych wyników wykazano, iż ekstrakty sterylizowane parą wodną pod ciśnieniem nie wykazują aktywności przeciwgrzybowej. W przypadku ekstraktu z korzenia, który charakteryzował się większą aktywnością inhibicyjną, uzyskano zaledwie 7% redukcję tempa wzrostu grzybni. Natomiast ekstrakt z korzenia poddany sterylizacji przez sączenie ograniczał o…
Standardisation of methods for assessing mould germination: a workshop report.
2006
International audience; The first workshop on predictive mycology was held in Marseille, France, 2–4 February 2005 under the auspices of the French Microbiological Society. The purpose of the workshop was to list the different techniques and definitions used by scientists for assessing mould germination and to evaluate the influence of the different techniques on the experimental results. Recommendations were made when a large consensus was obtained. In order to facilitate the study of germination, alternative methods to microscopic examination were examined.
The role of light in the emergence of weeds: using Camelina microcarpa as an example
2015
When modelling the emergence of weeds, two main factors are considered that condition this process: temperature and soil moisture. Optimum temperature is necessary for metabolic processes that generate energy for growth, while turgor pressure is necessary for root and shoot elongation which eventually leads to seedling emergence from the soil. Most emergence models do not usually consider light as a residual factor, but it could have an important role as it can alter directly or indirectly the dormancy and germination of seeds. In this paper, inclusion of light as an additional factor to photoperiod and radiation in emergence models is explored and compared with the classical hydrothermal t…
Modélisation des effets des systèmes de culture sur la levée des adventices à partir de relations fonctionnelles utilisant les traits des espèces
2008
The aim of the Ph. D. Was to adapt the monospecific model ALOMYSYS to a multi-specific flora, in order to predict the effects of cropping systems on the timing and quantities of emerging weed seedlings. Determining the parameters for each additional species is unfeasible. A second objective was thus to estimate the parameters from easily measurable species traits. After having performed a large literature analysis, 18 weeds were studied for the processes involved into the seedbank dynamics and emergence. The seed mortality in the soil could not be related with species traits and can be parameterised with literature data. A generic and simplified formalism represens the seasonal variations o…
Adventices : effets directs et indirects du réchauffement
2021
Contexte - Les conditions météorologiques extrêmes (gels, précipitations extrêmes, sécheresses automnale ou printanière) ont tendance à se multiplier, perturbant les pratiques agricoles,entraînant des pertes de rendement ou l’abandon de la culture. Les effets de la hausse des températures ou de l’allongement de l’ensoleillement sont plus marqués sur les dates de récoltepar exemple.Mais peut-on prévoir l’impact de ces changements climatiques sur les espèces adventices ?¾ effets diReCts - Les interactions entre caractéristiques climatiques, pratiques culturales et traits biologiques dechaque espèce rendent les prévisions difficiles. La hausse des températures peut avoir des effets directs sur…
Germination Pattern of Chamaerops humilis Seed after Short-Time Storage
2015
Dwarf fan palm (Chamaerops humilis) plays an important ecological role in the thermo Mediterranean vegetation stage, both in woodlands, xerophitic shrub communities and degraded ecosystems. Dwarf fan palm is typically propagated from seeds. Whereas other palm species show reduced germination after few months of seed storage, no information is available on the effects of storage time on seed germinability . We examined the germination pattern of dwarf palm seeds aged after a storage of four, six or eight months in comparison to fresh seed (control). A covariance analysis was performed to test the effect of time within seed-storage treatment. The germination patterns were significantly fitted…
Anàlisi de les estratègies germinatives d’espècies halòfiles
2018
En ambients halòfils de clima mediterrani com els localitzats en el litoral sud alacantí, l’ecofisiologia de la germinació és afectada essencialment pel dèficit hídric estacional, les elevades temperatures i les propietats del sòl. En aquest marc d’irregularitat ambiental, s’establí la resposta de germinació integrada en el cicle vital de l’espècie herbàcia halòfita Mesembryanthemum nodiflorum L. per tal d’avançar en el coneixement del funcionament d’aquests ambients salins i així poder abordar futurs programes de conservació vegetal en praderies salines. El protocol de germinació òptim de l’espècie d’estudi s’aconsegueix a un rang tèrmic de 25/10ºC i un fotoperíode de 12/12 h llum/obscurit…
Agricultural potential of anaerobically digested industrial orange waste with and without aerobic posttreatment
2012
The potential of anaerobically digested orange waste with (AAD) and without (AD) aerobic post-treatment for use in agriculture was evaluated through chemical analyses, short-term phytotoxicity and long-term plant assays. Chemical analyses showed that AD contained ammonia and organic acids, and aerobic post-treatment did not significantly remove these phytotoxins. The N:P2O5:K2O ratio in AD was 1:0.26:0.96 and aerobic post-treatment did not change the composition in AAD except for K2O (1:0.26:1.24). Heavy metal contents in AD and AAD were more or less the same and were below the upper limit recommended for non-sewage sludge application on agricultural soils. Short-term phytotoxicity tests sh…
Ginger and Turmeric Essential Oils for Weed Control and Food Crop Protection
2019
Ginger and turmeric are two food ingredients that are in high demand due to their flavor and positive effects on health. The biological properties of these spices are closely related to the aromatic compounds they contain. The chemical compositions of their essential oils and their in vitro phytotoxic activity against weeds (Portulaca oleracea, Lolium multiflorum, Echinochloa crus-galli, Cortaderia selloana, and Nicotiana glauca) and food crops (tomato, cucumber, and rice) were studied. Forty-one compounds, accounting for a relative peak area of 87.7% and 94.6% of turmeric and ginger essential oils, respectively, were identified by Gas Chromatography&ndash