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1.
In the present article, we investigated the epidermal and anatomical features of 10 wild Brassica juncea populations with different susceptibilities to glyphosate in detail. The characteristics of the leaf surface and anatomy could affect the efficacy of glyphosate uptake in weeds through the influence of its adherence and penetration. Our results showed that herbicide-resistant wild populations generally had greater leaf thickness, adaxial cutin thickness, and trichome density in the upper epidermis, but lower spongy tissue thickness and vascular bundle numbers, as compared with the susceptible populations, suggesting that differences in morphological traits among populations might contribute to their variable response to glyphosate. The possible morphological involvement in the differential susceptibility of wild B. juncea populations to glyphosate also was discussed. 相似文献
2.
Givens WA Shaw DR Newman ME Weller SC Young BG Wilson RG Owen MD Jordan DL 《Pest management science》2011,67(7):758-770
BACKGROUND: A survey was conducted with nearly 1200 growers in US states (Illinois, Indiana, Iowa, Mississippi, Nebraska and North Carolina) in 2005 with the objective in part of determining the awareness of the potential for development of glyphosate resistance, the experience with glyphosate‐resistant (GR) weeds and the sources of information that growers had utilized for information on glyphosate resistance. Growers were asked a series of questions to determine the level of glyphosate resistance awareness and to list the sources of information used to learn about glyphosate resistance issues. RESULTS: The majority of the growers (88%) were aware of a weed's potential to evolve resistance to herbicide, while 44% were aware of state‐specific documented cases of GR weeds, and 15% reported having had personal experience with GR weeds. Among sources of information concerning glyphosate resistance issues, farm publications, dealers/retailers and university/extension were the most frequent responses (41, 17 and 14% respectively). Based on a 1‐10 effectiveness scale, growers ranked tillage the least effective practice (5.5) and using the correct label rates of herbicides at the proper timing for the size and type of weeds present the most effective practice (8.6) with respect to how effectively the practices mitigated the evolution of GR weeds. CONCLUSION: Results from this survey can be used by researchers, extension specialists and crop advisors further to bridge the information gap between growers and themselves and better to disseminate information concerning glyphosate resistance and glyphosate resistance management practices through more targeted information and information delivery methods. Copyright © 2011 Society of Chemical Industry 相似文献
3.
目前,抗草甘膦杂草问题日趋严重。通过检索国内外抗草甘膦杂草的检测方法,总结出常用检测方法和其他检测方法,进行了简单概述,为抗草甘膦杂草检测体系的发展提供依据。 相似文献
4.
Studies were undertaken to determine Alternaria spp. associated with leaf spot symptoms on canola (Brassica napus) in two cropping seasons (2015, 2016) across southern Australia. Major allergen Alt a1 and plasma membrane ATPase genes were used to identify Alternaria spp. In 2015, 112 isolates of seven Alternaria spp. were obtained, with A. metachromatica predominating. In 2016, 251 isolates of 12 Alternaria spp. were obtained, with A. infectoria predominating. Alternaria spp. isolates were morphologically and phylogenetically identified and studies to determine their pathogenicity on both B. napus (cv. Thunder TT) and B. juncea (cv. Dune) confirmed 10 species (A. alternata, A. arborescens, A. brassicae, A. ethzedia, A. hordeicola, A. infectoria, A. japonica, A. malvae, A. metachromatica and A. tenuissima) as pathogenic on both Brassica species. Alternaria ethzedia, A. hordeicola and A. malvae were recorded for the first time in Australia on any host and the record of A. arborescens was the first for New South Wales (NSW) and South Australia (SA). Other first records included A. infectoria on B. napus in NSW; A. japonica on B. napus in NSW and Western Australia (WA); A. metachromatica on any host in NSW, Victoria (VIC), WA and SA; and A. tenuissima on B. napus in NSW, SA and WA. It is evident that alternaria leaf spot on canola across southern Australia is not solely caused by A. brassicae, but that a range of other Alternaria spp. are also involved to varying degrees, depending upon the year and the geographic locality. 相似文献
5.
Shaw DR Owen MD Dixon PM Weller SC Young BG Wilson RG Jordan DL 《Pest management science》2011,67(7):741-746
Glyphosate-resistant (GR) crop technology has dramatically impacted agriculture. The adoption of GR systems in canola, maize, cotton, soybean and sugar beets has been widespread in the United States. However, weed scientists are concerned that growers' current herbicide programs and weed management tactics will affect their sustainability and effectiveness. Without proper management, the potential for weed populations to express a high degree of resistance to glyphosate will adversely impact the utility of glyphosate. In 2005, weed scientists from six universities initiated a long-term research study to assess the sustainability of GR technology. This paper introduces five other articles in this series. Over 150 fields of at least 10 ha were selected to participate in a long-term field-scale study, and each field was split in half. On one-half the grower continued using the current weed management program; on the other half the grower used academic-recommended herbicide resistance best management practices. Field data were collected in 2006-2008 to determine the impact of the two weed management programs on weed populations, diversity, seedbank, crop yields and economic returns. This long-term study will provide invaluable data for determining the sustainability and profitability of diversified weed management programs designed to lower the risk of evolving weed resistance to glyphosate. 相似文献
6.
Alan M Dewar 《Pest management science》2009,65(10):1047-1058
Maize growing in the EU27 increased to over 13 million ha in 2007, most of which (>80%) was grown in just eight countries (France, Romania, Germany, Hungary, Italy, Poland, Spain and Bulgaria). The number of herbicides used to control the wide spectrum of weeds occurring in all these countries is likely to decline in the future as each current active ingredient is reassessed for toxicological and environmental safety under Directive 91/414/EEC. Glyphosate has already been approved under this directive. Glyphosate, applied alone or in combination with currently available residual herbicides to genetically modified varieties tolerant to glyphosate, can provide a viable, flexible and profitable alternative to conventional weed control programmes. Glyphosate usage with glyphosate‐tolerant varieties also provides an environmentally sustainable weed control option as long as sufficient diversity of weed management options (crop rotation, chemical diversity, multiple cultural and mechanical practices, buffer strips) is maintained within the farm management system. Appropriate product stewardship measures will be required to maximise the long‐term overall benefits of the glyphosate‐based system. Specifically, care will need to be taken to manage potential weed shifts to more difficult‐to‐control species and to reduce the risk of selection for glyphosate‐resistant weeds. Copyright © 2009 Society of Chemical Industry 相似文献
7.
Hugh J Beckie 《Pest management science》2011,67(9):1037-1048
This review focuses on proactive and reactive management of glyphosate‐resistant (GR) weeds. Glyphosate resistance in weeds has evolved under recurrent glyphosate usage, with little or no diversity in weed management practices. The main herbicide strategy for proactively or reactively managing GR weeds is to supplement glyphosate with herbicides of alternative modes of action and with soil‐residual activity. These herbicides can be applied in sequences or mixtures. Proactive or reactive GR weed management can be aided by crop cultivars with alternative single or stacked herbicide‐resistance traits, which will become increasingly available to growers in the future. Many growers with GR weeds continue to use glyphosate because of its economical broad‐spectrum weed control. Government farm policies, pesticide regulatory policies and industry actions should encourage growers to adopt a more proactive approach to GR weed management by providing the best information and training on management practices, information on the benefits of proactive management and voluntary incentives, as appropriate. Results from recent surveys in the United States indicate that such a change in grower attitudes may be occurring because of enhanced awareness of the benefits of proactive management and the relative cost of the reactive management of GR weeds. Copyright © 2011 Society of Chemical Industry 相似文献
8.
Masoud Asadi-Sabzi Eshagh Keshtkar Ali Mokhtassi-Bidgoli Stephen R. Moss 《Weed Research》2020,60(3):204-211
One side effect of human activity and global climatic change is more airborne dust. This not only has undesirable effects on human health and the environment, but may also adversely affect many agricultural processes, including herbicide efficacy. This is particularly relevant in parts of the world where dust storms are common and limited rainfall means dust persists on plants for protracted periods. Accordingly, a series of greenhouse dose–response pot experiments was carried out to quantify the effect of a dust concentration of 1,500 µg/m3 on the performance of paraquat, glyphosate, sulfosulfuron and 2,4-D+MCPA. Dust-treated and untreated seedlings of Hordeum spontaneum and Sinapis arvensis were sprayed with sulfosulfuron and 2,4-D+MCPA, respectively, while paraquat and glyphosate were applied to both weed species. The efficacy of glyphosate and paraquat decreased significantly in the presence of dust on both species. Similar results were observed for 2,4-D+MCPA on S. arvensis. In contrast, the efficacy of sulfosulfuron on H. spontaneum was not affected by dust. In the presence of dust, the doses of glyphosate, paraquat and 2,4-D+MCPA required for a 90% effect were enhanced by a factor of 1.9 to 2.6. The negative impact on glyphosate efficacy was more pronounced in S. arvensis than H. spontaneum, while it was similar for paraquat. Future studies should consider the amount, duration and composition of dust as well as its impact on other weeds and herbicides. Potential approaches to overcome the detrimental influence of dust on the performance of herbicides were also suggested for future studies. 相似文献
9.
The inheritance of partial resistance to race 2 of Albugo candida was studied in a canola-quality line of Brassica juncea . This partially resistant line was crossed with the susceptible B. juncea cultivar Commercial Brown. F1 , F1 (reciprocal), F2 , BC and doubled haploid generations from the cross were inoculated with a zoospore suspension of race 2 to study segregation of partial resistance. The partially resistant phenotype appeared to be controlled by a single dominant gene that has variable expression. This partial resistance can have implications in breeding for disease resistance against white rust, as adult plants did not develop hypertrophic growth or stagheads under greenhouse and field conditions. 相似文献
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Valentina Dwi Suci Handayani Yuki Tanno Masayuki Yamashita Hiroyuki Tobina Minoru Ichihara Yoshiki Ishida Hitoshi Sawada 《Weed Biology and Management》2017,17(2):84-90
Recently, glyphosate‐resistant Italian ryegrass (Lolium multiflorum Lam.) was found on rice paddy levees in a western region of Shizuoka Prefecture, Japan. Naturalized populations of Italian ryegrass are frequently infected with fungal Epichloë endophytes. Endophytes often confer benefits to their host grasses. This study investigated the influence of five weed management treatments on glyphosate resistance and endophyte infection in Italian ryegrass that was growing on paddy levees where glyphosate‐resistant individuals were dominant. The weed management treatments were: (i) mowing once before the grass flowered; (ii) mowing once during flowering; (iii) mowing twice during flowering; (iv) glyphosate application before flowering; and (v) no treatment. The seeds were collected from the treatment plots in 2013 and 2014. The seeds were examined for endophyte infection and the seedlings that had been grown from the seeds were tested for the frequency of glyphosate resistance. The seedlings that had been derived from the glyphosate treatment showed higher frequencies of glyphosate resistance than those seedlings that had been derived from all the other treatments. Endophytes were found in all populations of the seeds from the paddy levees, with higher infection rates in the seeds that had been derived from the glyphosate treatment and the twice‐mowed treatment. There was a significant relationship between the endophyte infection frequency in the seeds and glyphosate resistance in the seedlings that had been grown from the same populations. The results indicate that where glyphosate herbicides are frequently used, selection for glyphosate‐resistant Italian ryegrass occurs, and along with this, the frequency of endophyte infection also increases. 相似文献
12.
Vila-Aiub MM Balbi MC Distéfano AJ Fernández L Hopp E Yu Q Powles SB 《Pest management science》2012,68(3):430-436
BACKGROUND: In a large cropping area of northern Argentina, Sorghum halepense (Johnsongrass) has evolved towards glyphosate resistance. This study aimed to determine the molecular and biochemical basis conferring glyphosate resistance in this species. Experiments were conducted to assess target EPSPS gene sequences and 14C‐glyphosate leaf absorption and translocation to meristematic tissues. RESULTS: Individuals of all resistant (R) accessions exhibited significantly less glyphosate translocation to root (11% versus 29%) and stem (9% versus 26%) meristems when compared with susceptible (S) plants. A notably higher proportion of the applied glyphosate remained in the treated leaves of R plants (63%) than in the treated leaves of S plants (27%). In addition, individuals of S. halepense accession R2 consistently showed lower glyphosate absorption rates in both adaxial (10–20%) and abaxial (20–25%) leaf surfaces compared with S plants. No glyphosate resistance endowing mutations in the EPSPS gene at Pro‐101–106 residues were found in any of the evaluated R accessions. CONCLUSION: The results of the present investigation indicate that reduced glyphosate translocation to meristems is the primary mechanism endowing glyphosate resistance in S. halepense from cropping fields in Argentina. To a lesser extent, reduced glyphosate leaf uptake has also been shown to be involved in glyphosate‐resistant S. halepense . Copyright © 2011 Society of Chemical Industry 相似文献
13.
Parietaria debilis is a dominant annual weed in many non‐tillage fallow and undisturbed areas in Argentina. Herbicides control P. debilis inconsistently. A study on the growth of P. debilis, in a fallow in a soyabean–maize rotation including glyphosate‐resistant cultivars and in an undisturbed area without crops or weed control, was conducted in the central soyabean area of Argentina. The biomass dynamics of all species in the community, as well as biomass, density and growth traits of P. debilis were assessed. Biomass of several species including P. debilis and total biomass were greater in undisturbed than in fallow plots in both years of the study. Diversity was greater in undisturbed plots in 2000, but no differences in diversity were observed in 2001. In both treatments, P. debilis emergence began in March and finished in October and density increased from March to May. High mortality occurred in June and July, particularly in undisturbed plots. In the fallow plots, no other tall weed species were present and light interception was higher in spring when fruit production was at its peak. Conversely, in the undisturbed plots, P. debilis was substantially taller and had greater leaf area due to lower light interception by the high canopy of the rest of the community. In fallow, P. debilis is favoured by single applications of glyphosate, because the herbicide eliminates competitors. Control, if applied, should be directed to both fallow and undisturbed environments, as the weed produces considerable numbers of seeds and can invade extensively managed areas. 相似文献
14.
甲磺隆和草甘膦对空心莲子草乙酰乳酸合酶活性和莽草酸含量的影响 总被引：8，自引：0，他引：8
为研究甲磺隆和草甘膦对空心莲子草的作用机理,探索其最佳的使用技术,采用有效成分为30 g/hm2和60 g/hm2 的甲磺隆处理空心莲子草,能明显抑制其茎和根乙酰乳酸合酶的比活性;有效成分为1537.5g/ hm2和3075g/ hm2 的草甘膦处理则能明显抑制空心莲子草莽草酸含量的积累;施用甲磺隆和草甘膦对空心莲子草生长的抑制作用随药剂浓度的提高而增大.二次施用草甘膦(间隔30天)的结果表明,低剂量处理对抑制空心莲子草根组织莽草酸含量的积累更明显. 相似文献
15.
Valentina Atanackovic Alejandro Juárez‐Escario Jordi Recasens Joel Torra 《Weed Biology and Management》2015,15(3):122-131
The presence of herbicide‐resistant Lolium rigidum in Mediterranean (Spanish) citrus orchards was reported in 2005 and it poses a serious threat to crop management. The main objective of this research was to investigate which components could be responsible for the persistence of annual ryegrass populations in Mediterranean mandarin and orange orchards. This is the first study regarding L. rigidum populations in Mediterranean citrus orchards. Surveys were conducted in 55 commercial citrus orchards in eastern Spain in 2013 by interviewing technicians who were working in cooperatives about crop management. The level of infestation by L. rigidum and the presence of harvester ants (Messor barbarus) then were estimated in the same orchards. The variables were subjected to a two‐dimensional analysis and both univariate and multivariate logistic regression models were fitted for each of the three L. rigidum density levels that had been established. The multivariate models showed the significant factors that were associated with various L. rigidum densities: (i) at a low density, the herbicides that were applied, the number of applications in 2013 and the type of irrigation (flood or drip); (ii) at a medium density, the presence of harvester ants; and (iii) at a high density, the herbicides that were applied in 2013. The results indicated that drip irrigation and one application of glyphosate mixed with other herbicides (or herbicides other than glyphosate) were associated with a lower L. rigidum density. The alternative management options that are presented here should help farmers to reduce weed problems in Mediterranean citrus orchards. Future research is required to better understand the presence of herbicide‐resistant populations, as well as the possible beneficial presence of granivorous ant species. 相似文献
16.
Concerns have been raised about the possibility of sexual transfer of herbicide resistance genes from transgenic crops towards weedy relatives. The average rate of spontaneous hybridization between Hirschfeldia incana (L.) Lagrèze-Fossat and oilseed rape ( Brassica napus L.) was 0.6 hybrids per plant over 3 years of field experiments using herbicide-resistant oilseed rape as a pollen donor. Self-incompatibility was shown to be the mating system of most individuals within a population of H. incana , although some plants had some ability to self-fertilize, which could mitigate gene flow. Back-crossing interspecific hybrids to H. incana over five generations showed that introgression was not successful in our experiment. 相似文献
17.
Weirich JW Shaw DR Coble KH Owen MD Dixon PM Weller SC Young BG Wilson RG Jordan DL 《Pest management science》2011,67(7):785-789
BACKGROUND: The introduction of glyphosate‐resistant (GR) crops in the late 1990s made weed control in maize, cotton and soybean simple. With the rapid adoption of GR crops, many growers began to rely solely on glyphosate for weed control. This eventually led to the evolution of GR weeds. Growers are often reluctant to adopt a weed resistance best management practice (BMP) because of the added cost of additional herbicides to weed control programs which would reduce short‐term revenue. This study was designed to evaluate when a grower that is risk neutral (profit maximizing) or risk averse should adopt a weed resistance BMP. RESULTS: Whether a grower is risk neutral or risk averse, the optimal decision would be to adopt a weed resistance BMP when the expected loss in revenue is greater than 30% and the probability of resistance evolution is 0.1 or greater. However, if the probability of developing resistance increases to 0.3, then the best decision would be to adopt a weed resistance BMP when the expected loss is 10% or greater. CONCLUSION: Given the scenarios analyzed, risk‐neutral or risk‐averse growers should implement a weed resistance BMP with confidence that they have made the right decision economically and avoided the risk of lost revenue from resistance. If the grower wants to continue to see the same level of return, adoption of BMP is required. Copyright © 2011 Society of Chemical Industry 相似文献
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Components of disease reaction, including incubation period, pustule types, inoculum production and disease index (DI); and contents of protein, phenols, soluble sugars and reducing and non-reducing sugars were investigated in cotyledonary and true leaves of six genotypes of Brassica juncea : Varuna, Kranti, EC-399296, EC-399299, EC-399313 and EC-399301, inoculated with Albugo candida . Cotyledonary leaves were examined 14 days after inoculation (d.a.i.), whereas true leaves were scored 14 and 21 d.a.i. Disease indices were assessed on a 0% (resistant) to 100% (susceptible) scale. DIs at the cotyledonary leaf stage in the above six genotypes were 67, 65, 32, 31, 31 and 38%, respectively, whereas at the true-leaf stage they were 21, 28, 12, 17, 9 and 4%, respectively at 14 d.a.i., and 35, 45, 17, 19, 20 and 6%, respectively at 21 d.a.i. Protein contents were highest in the genotypes with the highest DIs, such as Varuna at the cotyledonary leaf stage and Kranti at the true-leaf stage, and lowest in the genotypes with the lowest DIs, such as EC-399299 at the cotyledonary stage and EC-399301 at the true-leaf stage. Total phenols, total sugars, reducing sugars and non-reducing sugars were generally negatively correlated with DI, but were not always consistent, particularly when differences in DI were small. The results indicated that factors conditioning the response of host genotypes to A. candida may differ or operate in different ways at different growth stages. 相似文献
20.
Weirich JW Shaw DR Owen MD Dixon PM Weller SC Young BG Wilson RG Jordan DL 《Pest management science》2011,67(7):781-784
BACKGROUND: Glyphosate‐resistant (GR) crops have changed the way growers manage weeds and implement control strategies. Since the introduction of GR crops, growers in many instances have relied on glyphosate almost exclusively to control a broad spectrum of weeds. This overreliance on glyphosate has resulted in the evolution of glyphosate resistance in some weed species. Growers and scientists are concerned about the sustainability of GR crops and glyphosate. When a grower is making decisions about weed control strategies, economic costs and benefits of the program are primary criteria for selection and implementation. Studies across six states were initiated in 2006 to compare the economics of using a weed resistance best management practice (BMP) system with a grower's standard production system. RESULTS: Resistance BMP systems recommended by university scientists were more costly but provided similar yields and economic returns. Rotation of GR crops resulted in a higher net return (maize and soybean) compared with continuous GR crop (cotton or soybean) or rotating a GR crop with a non‐GR crop (maize). CONCLUSION: Growers can implement weed resistance BMP systems with the confidence that their net returns will be equivalent in the short run, and, in the long term, resistance BMP systems will prevent or delay the evolution of GR weeds in their fields, resulting in substantial savings. Copyright © 2011 Society of Chemical Industry 相似文献