共查询到20条相似文献，搜索用时 15 毫秒
1.
Which future for weed science? 总被引：2，自引：0，他引：2
Weed science is a discipline dealing with a serious biotic threat capable of causing heavy economic, environmental or aesthetic losses to society. In the past, we have been successful in providing efficient, relatively cheap and safe technologies to manage this threat in a variety of situations. We have been able to provide practical advice and options for the end-users based on a broad scientific knowledge. In order to continue this success, we need to anticipate the future and change faster than the world around us. Numerous opportunities are open to us. Weed science should enter the global climate change arena, getting involved in both mitigation (improving the carbon efficiency of agriculture and forestry) and adaptation (developing effective practices for the new crops, new production systems and the new weeds). We should find adequate answers to the new demands originating from the enlargement of farms and fields, the increased concern about the conservation of biodiversity and the growing consumer demands on food safety. We should look for new clients in non-agricultural sectors, offering them our proved expertise and know-how. We should try to exploit the new opportunities arising as a result of cross-fertilisation of weed science with other disciplines. At the same time, we need to be aware of some threats: the dominance of short-term commercial and political objectives in setting research agendas, the reduced R&D resources invested in the agrochemical industry in the development of new herbicides and the increasing 'publish or perish' pressure in the public research sector. 相似文献
2.
Murray B Isman 《Pest management science》2015,71(12):1587-1590
Botanical insecticides continue to be a subject of keen interest among the international research community, reflected in the steady growth in scientific publications devoted to the subject. Until very recently though, the translation of that theory to practice, i.e. the commercialisation and adoption of new botanical insecticides in the marketplace, has seriously lagged behind. Strict regulatory regimes, long the bane of small pesticide producers, are beginning to relax some of the data requirements for ‘low‐risk’ pesticide products, facilitating movement of more botanicals into the commercial arena. In this paper I discuss some of the jurisdictions where botanicals are increasingly finding favour, some of the newer botanical insecticides in the plant and animal health arsenal and some of the specific sectors where botanicals are most likely to compete effectively with other types of insecticidal product. © 2015 Society of Chemical Industry 相似文献
3.
4.
Colin M Tice 《Pest management science》2001,57(1):3-16
Large numbers of compounds are now available through combinatorial chemistry and from compound vendors to screen for lead‐level agrochemical activity. The likelihood that compounds with whole‐organism activity will be discovered can be increased if compounds with physicochemical parameters consistent with transport to the target site are selected for screening. Certain ranges of simple parameters (molecular mass, log P, hydrogen‐bond donors and acceptors, rotatable bonds) have been correlated with oral bioavailability of drugs. The distribution of these parameters for commercial insecticides and post‐emergence herbicides was examined and ranges consistent with whole‐organism activity are proposed for the two classes of agrochemical. The most significant difference identified between drugs and these two classes of agrochemicals was the lower numbers of hydrogen‐bond donors allowed in the latter cases. The frequency with which certain functional groups occur in drugs and agrochemicals was also compared. © 2001 Society of Chemical Industry 相似文献
5.
David B. Collinge Ole Søgaard Lund Hans Thordal-Christensen 《European journal of plant pathology / European Foundation for Plant Pathology》2008,121(3):217-231
Insect and herbicide-resistant plants are the most widely grown transgenics in agricultural production. No strategy using genetically engineered plants for disease resistance has had a comparable impact. Why is this? What are the prospects for introducing transgenic disease resistant plants to agriculture? We review the biological background for strategies used to make disease resistant GM crops, illustrate examples of these different strategies and discuss future prospects. 相似文献
6.
Strigolactones are a class of natural and synthetic compounds that in the past decade have been exciting the scientific community not only for their intriguing biological properties but also for their potential applications in agriculture. These applications range from their use as hormones to modify and/or manage plant architecture, to their use as stimulants to induce seed germination of parasitic weeds and thus control their infestation by a reduced seed bank, to their use as ‘biostimulants’ of plant root colonisation by arbuscular mycorrhizal fungi, improving plant nutritional capabilities, to other still unknown effects on microbial soil communities. More recently, these compounds have also been attracting the interest of agrochemical companies. In spite of their biological attractiveness, practical applications are still greatly hampered by the low product yields obtainable by plant root exudates, by the costs of their synthesis, by the lack of knowledge of their off‐target effects and by the not yet specified or properly identified legislation that could regulate the use of these compounds, depending on the agricultural purposes. The aim of this article is to discuss, in the light of current knowledge, the different scenarios that might play out in the near future with regard to the practical application of strigolactones. © 2016 Society of Chemical Industry 相似文献
7.
8.
9.
The biology of late blight of potato and tomato, caused by Phytophthora infestans, changed when sexual reproduction by the pathogen became possible in many parts of the world, including Europe. In northern Europe, especially Scandinavia, there is increasing evidence that the pathogen is reproducing sexually on a regular basis, although in other regions further south or to the west it appears to reproduce primarily in a clonal manner. The presence of both mating types, the production of viable oospores, and observations of fields with soilborne sources of inoculum are consistent with sexual reproduction. Studies with different marker systems have revealed a population structure without any dominating clonal lineages in Scandinavia, and that is most easily explained by sexual reproduction. Phytophthora infestans recovered from the soil can also be linked to parental genotypes using likelihood‐based methods when codominant markers are used. A synthesis of all the available data points to a second centre of sexual reproduction in northern Europe. 相似文献
10.
Modelling weed seedling emergence pattern appears to be a promising approach in the development of effective weed management programmes based on the selection of optimal timing of control operations. Thermal and hydrothermal time models propose that seed germination rates are proportional to the amount by which temperature and water potential exceed threshold values for these environmental factors. Hence, base temperature for seed germination is a fundamental biological parameter for the prediction of weed emergence. A series of laboratory experiments were conducted to estimate base temperature in three weed species belonging to the Asteraceae family, predominant in conservation tillage fields in north‐eastern Italy. The traditional method based on germination assays at constant temperatures was compared with a method based on assays at alternating temperatures. The latter might represent an alternative to the former for those species which do not germinate or only poorly under constant temperatures. Base temperature was estimated by regressing the reciprocal of the median germination time on temperature comparing two functions, a broken‐stick and an exponential‐type model. Both models showed good fit to all data in the whole temperature range and in almost all cases provided similar estimates of base temperature. The main result is that, for the weed species examined in this study, the use of alternating temperatures for base temperature estimation appears to be possible. However, further research is required to test if the use of germination assays performed at alternating temperatures can be a suitable method to estimate base temperature of species that have too low germination at constant temperatures. 相似文献
11.
Robotic weeding's false dawn? Ten requirements for fully autonomous mechanical weed management 
下载免费PDF全文
下载免费PDF全文 C N Merfield 《Weed Research》2016,56(5):340-344
While machines called weeding robots are now commercially available and many more designs are being actively researched, I contend that current machines are not truly robotic weeders, rather they are essentially self‐guiding vehicles carrying weeding tools. I consider true robotic weeders to be a far more difficult objective. While advances in robotics have been outstanding, the weeding component often appears to be an afterthought. I contend that the weeding is as complex as the robotics. A genuine weeding robot should be able to: (i) monitor the crop, weeds, weather and soil, (ii) decide when the crop should be weeded, (iii) choose the optimal weeder, (iv) take the weeder to the field, (v) adjust the weeder for optimal performance, (vi) continuously monitor the entire weeder for blockages and mechanical breakages and fix them in the field, (vii) continuously monitor and adjust the weeder's performance, (viii) return the weeder to the farmyard and (ix) clean, maintain and store the weeder, that is replace all human intervention. This ten‐point list both defines and is a guide to what is required for completely autonomous robotic weeding. Currently, this list is far beyond current technology and it may be decades before it is realisable. The aim of this study therefore was not to disparage the achievements of agricultural roboticists, rather it is to highlight the complexity and demands of mechanical weeding and therefore describe what is really required to create a true robotic weeder. I therefore hope it will guide and expedite research and lead to more rapid success for robotic weeding. 相似文献
12.
As highly adaptable plants, weeds have evolved numerous mechanisms to evade control in agroecosystems. For example, reliance on herbicides has resulted in widespread evolution of resistance in many species. Minimising weed adaptation is a major driver for integrated weed management strategies. Crop mimicry is a notable example of weed adaptation, where weed species evolve to avoid control by mimicking aspects of the crop phenotype. Visual selection by hand weeding has been documented to select for crop mimics that are difficult to distinguish from the crop at the vegetative stage. With recent advancements in weed recognition technologies, image-based weed recognition for in-crop, site-specific weed control is on the cusp of becoming widely adopted. Whilst the control methods used in site-specific weed control will be varied (e.g., spot spraying or lasers), they will share weed recognition technology. Visual selection via image-based deep learning represents a selection pressure for weeds that can evade detection by mimicking crops. This mimicry may reduce weed recognition accuracy and thus weed control efficacy over time and result in difficult to manage mimetic weed phenotypes. Therefore, it is timely to explore the potential for selection of crop mimics by image-based weed recognition algorithms. 相似文献
13.
14.
Pike SM Heinz R Walk T Jones C Kraus GA Gassmann W Novacky AJ Niblack TL 《Phytopathology》2002,92(5):456-463
ABSTRACT This study explored the possibilities that changes in the egg shell/lipid layer electrical potential or pH communicate external hatching conditions to the Heterodera glycines second-stage juvenile (J2) within the mature egg and that electrophysiology could measure effects of chemicals on emergence. Potentials were measured following application of the emergence inducers (ZnSO(4) and ZnCl(2)), ions that do not affect emergence, or synthetic emergence inhibitors. Results were compared with pH measurements and emergence bioassays. Healthy appearing eggs had negative resting potentials. Application of ZnSO(4) caused a smooth depolarization. However, eggs containing J2 and immature eggs depolarized to a similar degree when ZnSO(4) was added. In addition, ZnSO(4), synthetic emergence inhibitors, and CaCl(2) caused similar depolarization, and some depolarization was measured in dye-permeable eggs and empty shells. Results suggest that change in cation surface charge contributed to depolarization and that Cl penetrated the egg shell/lipid layer without causing potential changes. In bioassays, zinc consistently stimulated emergence to a greater degree than H(2)O, other cations, or buffers, and counteracted emergence inhibitors. Zinc-caused emergence stimulation was independent of pH. In summary, it is concluded that depolarization and pH are not emergence signals and electrophysiology is unlikely to measure effectiveness of emergence stimulators or inhibitors. 相似文献
15.
16.
The current global area equipped for irrigation provides 30–40% of the world's gross food output. Water used for plant irrigation may harbour plant pathogens and foster their spread. This represents a serious risk for crop health, with heavy socio‐economic consequences. More specifically to plant pathogenic bacteria (PPB), a range of species have been reported from irrigation systems and their potential role in epidemic development has long been recognized. However, only a few studies have been performed to date on the ecology of PPB in the context of water habitats. Consequently, current knowledge of the biology, ecology and epidemiology of PPB in irrigation water is poor. In light of this, an attempt is made to describe the most relevant information concerning the role of open irrigation systems in the survival and dissemination of PPB throughout the range of cultivations and the possible consequences for crop health. The information described in this paper will help to improve understanding on the overlooked role of irrigation water as a reservoir of PPB. 相似文献
17.
18.
Shall we share? A repository for Open Research Data in agriculture and environmental sciences 下载免费PDF全文
下载免费PDF全文 Many initiatives actively encourage investigators to make their research data available, but the process of sharing data is perceived by most researchers more as a burden than as a chance to increase the visibility of their results and improve the value of their research. One of the main barriers to open research data (ORD) is the need for interoperable data e‐infrastructures that allow researchers to manage a whole scientific information life cycle and a variety of stakeholders from different sectors to retrieve and exploit these data. In the pilot project presented in this study an open access and open source repository was developed to store, preserve and make accessible heterogeneous agricultural ORD collected over decades of scientific research about plant‐microbe interactions, with a particular focus on plant virus disease symptoms. Additionally, a step‐by‐step installation guide to set up a repository and simple operating procedures for data stewardship were provided. 相似文献
19.
20.
What are the best predictors for invasive potential of weeds? Transferability evaluations of model predictions based on diverse environmental data sets for Flaveria bidentis 下载免费PDF全文
下载免费PDF全文 Ecological niche models are widely used in the study of weed invasions, yet best approaches for selecting ecologically relevant environmental predictors for weeds remain unresolved. Here, we evaluate niche model transferability based on diverse environmental data sets for an invasive herb, Flaveria bidentis. This species is native to South America, but has established populations in China that pose a threat to agriculture and animal husbandry. Relevant environmental data sets were selected via five statistical approaches: permutation importance (PI) and jackknife test (JK) in Maxent, variable importance identified by boosting regression trees (BRT), ecological niche factor analysis (ENFA) and a newly released algorithm based on a fluctuation index (FI). Climate spaces occupied by native South American and introduced Chinese populations were compared based on these environmental data sets. Native niche model predictions in China were compared across environmental data sets and model settings (i.e. default versus fine‐tuned Maxent settings). Results suggest that native and introduced populations occupy two distinct climate spaces, but that this divergence likely results from background effects. Niche models based on fine‐tuned Maxent settings generally showed better discrimination ability than those based on default settings. The best model discrimination in China was attained in the FI model using fine‐tuned settings, followed by the BRT model on default settings. The best models suggest that highly suitable areas at risk of invasion in China are to the west and north‐east of present distributional areas. Results presented here provide predictions for F. bidentis in particular, but also shed light on procedures for selecting ecologically relevant predictors for invasive species distributional predictions more generally. 相似文献