Search results for "Weed"

Evolution of common ragweed (Ambrosia artemisiifolia) resistance to herbicides : identification of genetic determinisms and application to molecular …

2022

Common ragweed (Ambrosia artemisiifolia L.), a particularly troublesome and allergenic weed, is mainly controlled in agricultural fields using ALS inhibitor herbicides. Recent cases of herbicide resistance have been reported in France and are jeopardising the efficacy of this mode of action. Both target site resistance (TSR, structural mutation in ALS gene) and non target site resistance (NTSR, regulatory and/or structural mutations in secondary metabolism) are involved. The fundamental aim of this work was to identify the genetic determinisms of resistance to ALS inhibitors that have evolved in common ragweed populations in France. As an applied objective, this work also aimed to prepare t…

Stand-Alone or Combinatorial Effects of Grafting and Microbial and Non-Microbial Derived Compounds on Vigour, Yield and Nutritive and Functional Qual…

2022

The current research investigated the effects of endophytic fungi such as Trichoderma atroviride (Ta) or Ascophyllum nodosum seaweed extract (An) and their combination on growth, yield, nutritive and functional features, and mineral profile of ‘Birgah’ F1 eggplant either ungrafted, self-grafted or grafted onto the Solanum torvum rootstock. Eggplant exposed to An or An+Ta had a significant increase in root collar diameter 50 days after transplanting (RCD50), total yield (TY), marketable yield (MY), ascorbic acid (AA) content, Mg, Cu, and Zn concentration, and a reduction in glycoalkaloids (GLY) compared with the control. Furthermore, grafted plants had a higher TY, MY, number of marketable f…

Invasive vascular plant species of oxbow lakes in south-western Poland

2015

Abstract Natural water reservoirs are very valuable floristic sites in south-western Poland. Among them, the most important for the preservation of biodiversity of flora are oxbow lakes. The long-term process of human pressure on habitats of this type caused disturbances of their biological balance. Changes in the water regime, industrial development and chemisation of agriculture, especially in the period of the last two hundred years, led to systematic disappearances of localities of many plant species connected with rare habitats and also to the appearance of numerous invasive plant species. They are: Azolla filiculoides, Echinocystis lobata, Erechtites hieraciifolia, Impatiens glandulif…

Individuazione del periodo critico per il controllo delle infestanti in cece e favino.

2011

"Try again, fail better" : detecting the intersectionality of white female protagonist in Weeds

2012

Tutkielman tarkoituksena on selvittää kuinka televisiosarja Weedsin naispäähahmon identiteetti rakentuu intersektiävistä subjektipositioista. Subjektipositioilla tarkoitetaan positioita kuten luokka tai sukupuoli, joiden kautta yksilö kohtaa maailman ja joiden kautta hänet määritellään. Tutkimusaineistona on käytetty televisiosarja Weedsin kaikkia kahdeksaa tuotantokautta, jotta identiteetin rakentuminen prosessina voidaan hahmottaa selvemmin. Televisiosarja Weeds (2005- 2012) keskittyy marijuanaa välittävään yksinhuoltajaäitiin ja hänen perheeseensä. Sarja on esimerkillinen tutkimuskohde intersektionaaliselle analyysille sillä se nostaa esille monia yhteiskunnan epäkohtia ja esittää päähen…

Weed detection by aerial imaging: impact of soil, crop and weed spectral mixing

2015

International audience; This study aims to evaluate spectral information potential of images captured with a UAV, for site specific weed management. The image acquisition chain was modeled in order to compute the digital values of image pixels, according to the field conditions and objects lying on the ground surface projected in the pixels. The object spectra are mixed in the same pixel to estimate the impact of the spatial resolution of the image. The classification potential into crop, weed and soil classes was studied usinf simulations based on the present multispectral sensor characteristics and according to different mixing rates.

Biological Flora of the British Isles: Ambrosia artemisiifolia

2015

This account presents information on all aspects of the biology of Ambrosia artemisiifolia L. (Common ragweed) that are relevant to understanding its ecology. The main topics are presented within the standard framework of the Biological Flora of the British Isles: distribution, habitat, communities, responses to biotic factors, responses to environment, structure and physiology, phenology, floral and seed characters, herbivores and disease, and history, conservation, impacts and management. Ambrosia artemisiifolia is a monoecious, wind-pollinated, annual herb native to North America whose height varies from 10 cm to 2.5 m, according to environmental conditions. It has erect, branched stems …

Weeds sampling for map reconstruction: a Markov random field approach

2012

In the past 15 years, there has been a growing interest for the study of the spatial repartition of weeds in crops, mainly because this is a prerequisite to herbicides use reduction. There has been a large variety of statistical methods developped for this problem ([5], [7], [10]). However, one common point of all of these methods is that they are based on in situ collection of data about weeds spatial repartition. A crucial problem is then to choose where, in the eld, data should be collected. Since exhaustive sampling of a eld is too costly, a lot of attention has been paid to the development of spatial sampling methods ([12], [4], [6] [9]). Classical spatial stochastic model of weeds cou…

Does landscape diversity influence species fitness in farmland plants ?

2015

In agriculture, landscape management research has proven extremely valuable for explaining species amount, such as how species capture and utilize changed landscape resources to maintain population size and community diversity. What is surprising is the apparent lack of comparable studies on the effects of landscape properties and management on species fitness. Here, we search for "pathological" situations where landscape effects on farmland plant amount mask significantly different effects on fitness. We examined the case of 83 weed species in 256 fields distributed across the UK national scale. Whether at the local scale of the neighborhood or the larger scale of 2 km, we find landscape e…

Diversité fonctionnelle au sein des communautés de plantes adventices : effet de la rotation et du type de culture

2012

During this internship I investigated the effects of habitats i.e. field margin or the core of the field, and of crop sequences weed taxonomic and functional diversity in arable fields. We selected 75 fields from a database of flora surveys that have been conducted since 2005 in the area of Fénay. In the 75 fieds, the flora was sampled four consecutive years. The indices of Shannon-Weaver, Simpson and Pielou and species richness were selected for taxonomic study, while Rao's quadratic entropy and the community weighted mean (CWM) of the traits in the community were used for the functional study. Four functional traits were selected for the analyses. Our results showed that all studied facto…