Dispersal and Frequency of Glyphosate-Resistant and Glyphosate-Tolerant Weeds in Soybean-producing Edaphoclimatic Microregions in Brazil

AbstractGlyphosate-resistant (GR) and glyphosate-tolerant weeds cause considerable yield losses and represent a growing threat to soybean production systems. Despite the relevance of this topic, few studies have evaluated the dispersal of these species in Brazil. The objective of this study was to evaluate the dispersal and frequency of known GR and glyphosate-tolerant weeds in soybean-producing microregions. A total of 2,481 interviews were conducted in different regions of Brazil. The interviews were stratified among 20 edaphoclimatic microregions (ECRs) to cover all of the country’s soybean-producing regions. A minimum number of interviews was estimated to generate a margin of error of ≤10% within the ECRs and ≤5% in the country. The values of the farmers’ responses were extrapolated to the total soybean production area of each ECR and the country as a whole, and the absolute values of each response were normalized as percentage values. The dispersal and management data demonstrate a loss of efficiency of glyphosate-resistance technology. Species that are naturally tolerant to glyphosate such as goosegrass, Commelina spp., and Ipomoea spp. had a greater presence in the ECRs, as did the resistant biotypes, particularly Conyza spp. and sourgrass, due to the large area cultivated with GR soybean, where glyphosate has been used with high frequency.

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Occurrence and importance of plant-parasitic nematodes in organic farming in Germany

Nematology ◽

10.1163/156854107782331261 ◽

2007 ◽

Vol 9 (6) ◽

pp. 869-879 ◽

Cited By ~ 16

Author(s):

Andrea Frankenberg ◽

Andreas Paffrath ◽

Johannes Hallmann ◽

Harald Schmidt

Keyword(s):

Organic Farming ◽

High Frequency ◽

Production Systems ◽

Parasitic Nematodes ◽

Yield Losses ◽

Plant Parasitic Nematodes ◽

Severe Damage ◽

Production Factors ◽

Main Emphasis ◽

Plant Parasitic

AbstractIn an attempt to evaluate the occurrence and economic importance of plant-parasitic nematodes in organic farming in Germany, a survey was conducted with the main emphasis on vegetable and cereal production systems. For vegetables, the survey included quantification and identification of plant-parasitic nematodes in soil samples and a questionnaire for growers querying production factors and damage levels. For cereals, the survey focused on quantification and identification of plant-parasitic nematodes in soil and plant samples. Overall, Pratylenchus and Tylenchorhynchus were the most prominent nematode genera under both production systems with an incidence of over 90% of the samples. Meloidogyne was detected in 51% of the samples in both systems. Other nematode genera showed differences between the two production systems. In production systems with a high frequency of vegetables, Paratylenchus was detected in 56% of the samples and Heterodera in 15%, whereas in rotations with a high cropping frequency of cereals, incidences of plant-parasitic nematodes were 56% for Heterodera, 47% for Trichodorus and 45% for Paratylenchus. Yield losses could exceed 50% on carrots, onions and cereals and were most pronounced on sandy soils. In many cases, nematode problems started 5 to 10 years after conversion to organic farming. The survey indicated that plant-parasitic nematodes are widely spread in organic farming in Germany and can cause severe damage which may result in complete loss of the crop.

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Modeling the relationship between estimated fungicide use and disease-associated yield losses of soybean in the United States II: Seed-applied fungicides vs seedling diseases

PLoS ONE ◽

10.1371/journal.pone.0244424 ◽

2020 ◽

Vol 15 (12) ◽

pp. e0244424

Author(s):

Ananda Y. Bandara ◽

Dilooshi K. Weerasooriya ◽

Shawn P. Conley ◽

Tom W. Allen ◽

Paul D. Esker

Keyword(s):

United States ◽

Production Systems ◽

Regional Scale ◽

The United States ◽

Annual Data ◽

Yield Losses ◽

Soybean Production ◽

The Relationship ◽

The U.S ◽

Seedling Diseases

Use of seed-applied fungicides has become commonplace in the United States soybean production systems. Although fungicides have the potential to protect seed/seedlings from critical early stage diseases such as damping-off and root/stem rots, results from previous studies are not consistent in terms of seed-applied fungicide’s ability to mitigate yield losses. In the current study, the relationship between estimated soybean production losses due to seedling diseases and estimated seed-applied fungicide use was investigated using annual data from 28 soybean growing states in the U.S. over the period of 2006 to 2014. National, regional (northern and southern U.S.), state, and temporal scale trends were explored using mixed effects version of the regression analysis. Mixed modeling allowed computing generalized R2 values for conditional (R2GLMM(c); contains fixed and random effects) and marginal (R2GLMM(m); contains only fixed effects) models. Similar analyses were conducted to investigate how soybean production was related to fungicide use. National and regional scale modeling revealed that R2GLMM(c) values were significantly larger compared to R2GLMM(m) values, meaning fungicide use had limited utility in explaining the national/regional scale variation of yield loss and production. The state scale analysis revealed the usefulness of seed-applied fungicides to mitigate seedling diseases-associated soybean yield losses in Illinois, Indiana, North Carolina, and Ohio. Further, fungicide use positively influenced the soybean production and yield in Illinois and South Dakota. Taken together, use of seed-applied fungicide did not appear to be beneficial to many of the states. Our findings corroborate the observations made by a number of scientists through field scale seed-applied fungicide trials across the U.S and reiterate the importance of need base-use of seed-applied fungicides rather than being a routine practice in soybean production systems.

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Sorption of pesticides used in banana production on soils of Ecuador

Soil Research ◽

10.1071/sr02015 ◽

2002 ◽

Vol 40 (7) ◽

pp. 1085 ◽

Cited By ~ 15

Author(s):

Tanya Cáceres ◽

Guang-Guo Ying ◽

Rai Kookana

Keyword(s):

River Basin ◽

Ecosystem Health ◽

Production Systems ◽

Parent Compound ◽

Mean Value ◽

Organic Carbon Content ◽

Banana Production ◽

Kd Values ◽

Production Area ◽

Impact Of Pesticides

There is concern about the migration and adverse impact of pesticides used in banana production systems in Ecuador on aquaculture and ecosystem health. Therefore, we studied the sorption of chlorothalonil, fenamiphos, and its 2 metabolites (fenamiphos sulfone and fenamiphos sulfoxide), by batch method on 6 surface soils from the Guayas River Basin (1–3�S, 79–81�W), a major banana production area of Ecuador. The sorption of chlorothalonil on the 6 soils was high and varied considerably as shown by the Kd values ranging from 68.50 to 152.60 L/kg. The sorption coefficients normalised with the organic carbon content of soil (Koc) for chlorothalonil ranged from 2330 to 7336 kg/L, with a mean value of 4012 kg/L. These Koc values are higher than those previously reported in the literature. The sorption of fenamiphos and its metabolites to the 6 soils varied among soils in a similar pattern. The Kd values ranged from 5.66 to 14.31�L/kg for fenamiphos, from 2.81 to 8.79 L/kg for fenamiphos sulfone, and from 0.77 to 4.00 L/kg for fenamiphos sulfoxide, respectively. In all of the soils the sorption coefficients of both metabolites of fenamiphos were lower than that for the parent compound. The Koc values ranged from 220 to 515 kg/L (mean value 371 kg/L) for fenamiphos, from 29 to 141 kg/L (mean value of 76 kg/L) for fenamiphos sulfoxide, and from 79 to 334 kg/L (mean value of 191 kg/L) for fenamiphos sulfone. Chlorothalonil had much stronger sorption than fenamiphos and its metabolites on the Ecuadorian soil. Due to lower sorption and therefore greater mobility and longer persistence of the fenamiphos metabolites, these compounds need adequate consideration during residue monitoring and assessment of potential off-site impacts on ecosystem health and aquaculture in the Guayas River Basin.

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Flood Risk and Adaptation Strategies for Soybean Production Systems on the Flood-Prone Pampas under Climate Change

Agronomy ◽

10.3390/agronomy11061187 ◽

2021 ◽

Vol 11 (6) ◽

pp. 1187

Author(s):

Wouter Julius Smolenaars ◽

Spyridon Paparrizos ◽

Saskia Werners ◽

Fulco Ludwig

Keyword(s):

Climate Change ◽

Flood Risk ◽

Risk Perceptions ◽

Production Systems ◽

Adaptation Strategies ◽

Flood Events ◽

Climate Data ◽

Soybean Production ◽

Drying Trend ◽

Sowing Season

In recent decades, multiple flood events have had a devastating impact on soybean production in Argentina. Recent advances suggest that the frequency and intensity of destructive flood events on the Argentinian Pampas will increase under pressure from climate change. This paper provides bottom-up insight into the flood risk for soybean production systems under climate change and the suitability of adaptation strategies in two of the most flood-prone areas of the Pampas region. The flood risk perceptions of soybean producers were explored through interviews, translated into climatic indicators and then studied using a multi-model climate data analysis. Soybean producers perceived the present flood risk for rural accessibility to be of the highest concern, especially during the harvest and sowing seasons when heavy machinery needs to reach soybean lots. An analysis of climatic change projections found a rising trend in annual and harvest precipitation and a slight drying trend during the sowing season. This indicates that the flood risk for harvest accessibility may increase under climate change. Several adaptation strategies were identified that can systemically address flood risks, but these require collaborative action and cannot be undertaken by individual producers. The results suggest that if cooperative adaptation efforts are not made in the short term, the continued increase in flood risk may force soybean producers in the case study locations to shift away from soybean towards more robust land uses.

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Soil Bacterial Community Diversity and Composition as Affected by Tillage Intensity Treatments in Corn-Soybean Production Systems

Microbiology Research ◽

10.3390/microbiolres12010012 ◽

2021 ◽

Vol 12 (1) ◽

pp. 157-172

Author(s):

Shankar G. Shanmugam ◽

Normie W. Buehring ◽

Jon D. Prevost ◽

William L. Kingery

Keyword(s):

Microbial Community ◽

Bacterial Community ◽

Community Composition ◽

Production System ◽

Soil Microbial Community ◽

Production Systems ◽

Bacterial Community Composition ◽

Soybean Production ◽

Soil Microbial ◽

Soil Bacterial

Our understanding on the effects of tillage intensity on the soil microbial community structure and composition in crop production systems are limited. This study evaluated the soil microbial community composition and diversity under different tillage management systems in an effort to identify management practices that effectively support sustainable agriculture. We report results from a three-year study to determine the effects on changes in soil microbial diversity and composition from four tillage intensity treatments and two residue management treatments in a corn-soybean production system using Illumina high-throughput sequencing of 16S rRNA genes. Soil samples were collected from tillage treatments at locations in the Southern Coastal Plain (Verona, Mississippi, USA) and Southern Mississippi River Alluvium (Stoneville, Mississippi, USA) for soil analysis and bacterial community characterization. Our results indicated that different tillage intensity treatments differentially changed the relative abundances of bacterial phyla. The Mantel test of correlations indicated that differences among bacterial community composition were significantly influenced by tillage regime (rM = 0.39, p ≤ 0.0001). Simpson’s reciprocal diversity index indicated greater bacterial diversity with reduction in tillage intensity for each year and study location. For both study sites, differences in tillage intensity had significant influence on the abundance of Proteobacteria. The shift in the soil bacterial community composition under different tillage systems was strongly correlated to changes in labile carbon pool in the system and how it affected the microbial metabolism. This study indicates that soil management through tillage intensity regime had a profound influence on diversity and composition of soil bacterial communities in a corn-soybean production system.

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A Survey of Glyphosate-Resistant Waterhemp (Amaranthus rudis) in Missouri Soybean Fields and Prediction of Glyphosate Resistance in Future Waterhemp Populations Based on In-Field Observations and Management Practices

Weed Technology ◽

10.1614/wt-d-13-00042.1 ◽

2013 ◽

Vol 27 (4) ◽

pp. 656-663 ◽

Cited By ~ 9

Author(s):

Kristin K. Rosenbaum ◽

Kevin W. Bradley

Keyword(s):

Crop Production ◽

Management Practices ◽

Production Systems ◽

Glyphosate Resistance ◽

Continuous Cropping ◽

Field Observations ◽

Weed Species ◽

Herbicide Treatment ◽

Amaranthus Rudis

A survey of soybean fields containing waterhemp infestations was conducted just prior to harvest in 2008 and 2009 to determine the frequency and distribution of glyphosate-resistant waterhemp in Missouri, and to determine if there are any in-field parameters that may serve as indicators of glyphosate resistance in this species in future crop production systems. Glyphosate resistance was confirmed in 99 out of 144, or 69%, of the total waterhemp populations sampled, which occurred in 41 counties of Missouri. Populations of glyphosate-resistant waterhemp were more likely to occur in fields with no other weed species present at the end of the season, continuous cropping of soybean, exclusive use of glyphosate for several consecutive seasons, and waterhemp plants showing obvious signs of surviving herbicide treatment compared to fields characterized with glyphosate-susceptible waterhemp. Therefore, it is suggested that these four site parameters, and certain combinations of these parameters, serve as predictors of glyphosate resistance in future waterhemp populations.

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Plant breeding in the semiarid region of Brazil: examples of success

Cropp Breeding and Applied Biotechnology ◽

10.1590/s1984-70332012000500007 ◽

2012 ◽

Vol 12 (spe) ◽

pp. 57-66 ◽

Cited By ~ 1

Author(s):

Manoel Abílio de Queiroz ◽

Levi de Moura Barros ◽

Luiz Paulo de Carvalho ◽

Jonas de Araújo Candeia ◽

Edinardo Ferraz

Keyword(s):

Cotton Fiber ◽

Production Systems ◽

Rio Grande ◽

Semiarid Region ◽

Breeding Programs ◽

Caatinga Biome ◽

Colored Cotton ◽

Nut Production ◽

Production Area ◽

Naturally Colored Cotton

The Northeastern region of Brazil comprises the Caatinga biome (900,000 km²) part of which is a semiarid region with rainfed and irrigated production systems. Among the successful breeding programs are cashew and cotton. The first led to a substantial increase in nut production in Ceará, Rio Grande do Norte and Piauí and the second bred a naturally colored cotton fiber, now processed in small clothing industries in Paraiba, exporting to 11 countries. In the lower-middle São Francisco valley, the previously grown onion was replaced by improved varieties, on 90% of the production area, and by industrial tomato, introduced by research in 1972, which came to be used on more than 80% of the area at the time. The participation of the private sector and continuity of breeding programs were crucial for the success. More examples of success are expected with the establishment of postgraduate courses in Agricultural Sciences in the Semiarid region.

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High Frequency of OXA-253-Producing Acinetobacter baumannii in Different Hospitals in Recife, Brazil

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.01309-16 ◽

2016 ◽

Vol 61 (1) ◽

Cited By ~ 3

Author(s):

Felipe Lira de Sá Cavalcanti ◽

Carina Lucena Mendes-Marques ◽

Crhisllane Rafaele dos Santos Vasconcelos ◽

Túlio de Lima Campos ◽

Antonio Mauro Rezende ◽

...

Keyword(s):

Acinetobacter Baumannii ◽

High Frequency ◽

Resistance Determinant ◽

Large Area ◽

Content Type ◽

Successful Transmission ◽

Genetic Environment ◽

Reported Data ◽

Sequence Types

ABSTRACT Here, we report the isolation of 31 Acinetobacter baumannii strains producing OXA-253 in a single large Brazilian city. These strains belonged to five different sequence types (STs), including 4 STs not previously associated with bla OXA-253. In all strains, the bla OXA-253 gene was located in a plasmid within a genetic environment similar to what was found previously in Brazil and Italy. The reported data emphasize the successful transmission of the bla OXA-253 gene through a large area and the tendency for this resistance determinant to remain in the A. baumannii population.

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Self-consistent electrodynamics of large-area high-frequency capacitive plasma discharge

Journal of Applied Physics ◽

10.1063/1.3489950 ◽

2010 ◽

Vol 108 (7) ◽

pp. 073301 ◽

Cited By ~ 33

Author(s):

Zhigang Chen ◽

Shahid Rauf ◽

Ken Collins

Keyword(s):

High Frequency ◽

Plasma Discharge ◽

Large Area ◽

Self Consistent

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Astrometry With Schmidt Telescopes

International Astronomical Union Colloquium ◽

10.1017/s025292110010661x ◽

1984 ◽

Vol 78 ◽

pp. 217-224

Author(s):

C A Murray

Keyword(s):

Reference Frame ◽

Proper Motions ◽

Large Area ◽

Full Field ◽

Potential Value ◽

Focal Surface ◽

Single Plate ◽

Trigonometric Parallaxes ◽

The Absolute

Photographic astrometry, including work with Schmidt telescopes, can be divided into two main fields, (i) the measurement of positions of objects relative to a reference frame of stars with known celestial coordinates, and (ii) the measurement of relative proper motions and trigonometric parallaxes from a series of plates taken on the same field. The former demands a knowledge of the absolute transformation between angles on the sky and measurements on a plate, whereas in the latter we are only interested in differential transformations from plate to plate. The potential value of Schmidt telescopes for both these fields of astrometry lies in the large area of sky and range of magnitude which can be imaged on a single plate. The former advantage is however, to some extent offset by the curvature of the focal surface which means that, in order to utilize the full field the plates must be constrained to the form of the focal surface during exposure.

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