Estrategias de manejo y control de Rama Negra en sistemas de producción

Esta maleza se ha convertido en un serio problema para la producción de nuestra zona y gran parte de la región agrícola de nuestro país. Conocerla y actuar en momentos adecuados es la estrategia que se debe tener en cuenta para su control.EEA BarrowFil: Istilart, Carolina Maria. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Barrow; ArgentinaFil: Gigón, Ramón. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Barrow; Argentin

Producción de forraje en pasturas fertilizadas de agropiro alargado

La ganadería es la actividad productiva casi exclusiva en los suelos con problemas de anegamiento y/o salinidad-alcalinidad. Las pasturas adaptadas a estos suelos, con manejos específicos como fertilización, tienen el potencial de incrementar sustancialmente la productividad de esos ambientes marginales para la agriculturaEEA BarrowFil: Duhalde, Jose Maria. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Barrow; ArgentinaFil: Perea, Andrés Ricardo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Barrow; ArgentinaFil: Gigón, Ramón. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Barrow; Argentin

¿Cuánto paga una maleza por ser resistente a un herbicida?

La resistencia a herbicidas suele tener un costo energético para las malezas. Esto se traduce en una menor producción de semillas comparado a las plantas susceptibles. El conocimiento de estos aspectos ecológicos permite diseñar estrategias de manejo donde se favorezcan las plantas susceptibles a expensas de las resistentes.EEA BarrowFil: Yanniccari, Marcos. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Barrow; ArgentinaFil: Gigón, Ramón. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Barrow; ArgentinaFil: Istilart, Carolina Maria. Instituto Nacional de Tecnología Agropecuaria (INTA). Chacra Experimental Integrada Barrow; Argentin

Suppression of Lolium multiflorum Lam. with Vicia villosa Roth combined with residual herbicides

Lolium multiflorum Lam. (annual ryegrass) is a problematic weed species especially in no-tillage systems of the southern region of Buenos Aires province (Argentina). Increasing herbicide resistance cases have exacerbated the problem, requiring alternative control options based on an Integrated Weed Management approach (IWM). Field experiments were conducted in the south area of Buenos Aires province during 2017-2019 in order to evaluate both the suppressive effect of Vicia villosa (hairy vetch) over annual ryegrass when combined with residual herbicides, and the tolerance of the former to such herbicides. Annual ryegrass stand density and biomass at crop termination were reduced from 2 - 98% in response to combined hairy vetch plus herbicide treatments. Among the best chemical options, pyroxasulfone, acetochlor and S-metolachlor should be mentioned, reaching weed biomass control values of 97, 81 and 76%, respectively. Hairy vetch was partially affected by herbicides with a plant stand reduction ≤ 48%. No significant effect on biomass at crop termination was observed, except for diflufenican and trifluralin. The inclusion of hairy vetch as cover crop combined with residual herbicides could be a practical IWM practice for suppression of annual ryegrass populations resistant to ACCase, ALS and EPSPS inhibitors.Lolium multiflorum Lam. (raigrás anual) es una especie de maleza problemática, especialmente en los sistemas de labranza cero en el sur de Buenos Aires (Argentina). El aumento de los casos de resistencia a los herbicidas ha exacerbado el problema, requiriendo opciones de control alternativas basadas en un enfoque de manejo integrado de malezas (MIM). Los experimentos a campo se llevaron a cabo en el área sur de la provincia de Buenos Aires durante 2017-2019 con el fin de evaluar tanto el efecto supresor de Vicia villosa (vicia villosa) sobre raigrás cuando se combinan con herbicidas residuales y la tolerancia de la vicia villosa a tales herbicidas. La densidad de plantas y la biomasa al final del raigrás anual se redujeron del 2 al 98% en respuesta al cultivo de vicia villosa combinado con los tratamientos con herbicidas. Entre las mejores opciones químicas, se debe mencionar a pyroxasulfone, acetochlor y S-metolachlor, alcanzando valores de control de biomasa de raigrás del 97, 81 y 76%, respectivamente. La vicia villosa se vio parcialmente afectada por los herbicidas con una reducción del stand de implantación de ≤ 48%. No se observó ningún efecto significativo sobre la biomasa en el momento de terminación del cultivo, excepto con diflufenican y trifluralina. La inclusión de vicia villosa como cultivo de cobertura combinado con herbicidas residuales podría ser una práctica de MIM para la supresión de poblaciones de raigrás anual resistentes a los inhibidores de ACCase, ALS y EPSPS.EEA Hilario AscasubiFil: Renzi Pugni, Juan Pablo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Hilario Ascasubi; Argentina.Fil: Renzi Pugni, Juan Pablo. Universidad Nacional del Sur. Departamento de Agronomía; ArgentinaFil: Pérez Aagaard, Cristián. Universidad Nacional del Sur. Departamento de Agronomía; ArgentinaFil: Chantre Balacca, Guillermo Ruben. Universidad Nacional del Sur. Departamento de Agronomía; Argentina.Fil: Chantre Balacca, Guillermo Ruben. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiarida; ArgentinaFil: Chantre Balacca, Guillermo Ruben. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiarida; ArgentinaFil: Gigón, Ramón. Asesor privado; ArgentinaFil: Reinoso, Omar Juan. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Hilario Ascasubi; ArgentinaFil: Quintana, Matias. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Hilario Ascasubi; ArgentinaFil: Ducos, I. Criadero El Cencerro (Coronel Suárez); ArgentinaFil: Cantamutto, Miguel Angel. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Hilario Ascasubi; Argentina.Fil: Cantamutto, Miguel Angel. Universidad Nacional del Sur. Departamento de Agronomía; ArgentinaFil: Cantamutto, Miguel Angel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiarida; ArgentinaFil: Cantamutto, Miguel Angel. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiarida; Argentin

La evolución del ryegrass resistente a glifosato en la región

El ryegrass resistente a glifosato constituye una de las malezas difíciles en la producción de cereales de invierno. La genética de las plantas resistentes juega un rol crucial en la evolución de la resistencia, por lo tanto su conocimiento conduce al diseño de estrategias de manejo racional.EEA BarrowFil: Yanniccari, Marcos Ezequiel. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Barrow; ArgentinaFil: Istilart, Carolina Maria. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Barrow; ArgentinaFil: Gigón, Ramón. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Barrow; Argentin

Constitutive overexpression of EPSPS by gene duplication is involved in glyphosate resistance in Salsola tragus

Background: Glyphosate-resistant Salsola tragus accessions have been identified in the USA and Argentina; however, the mechanisms of glyphosate resistance have not been elucidated. The goal of this study was to determine the mechanism/s of glyphosate resistance involved in two S. tragus populations (R1 and R2) from Argentina. Results: Both glyphosate-resistant populations had a 6-fold lower sensitivity to glyphosate than the S population (i.e. resistance index). No evidence of differential absorption, translocation or metabolism of glyphosate was found in the R1 and R2 populations compared to a susceptible population (S). No EPSPS mutations were detected, but S. tragus R1 and R2 plants had approximately 14-fold higher EPSPS gene relative copy number compared to the S counterpart. In R1 and R2, EPSPS duplication entailed a greater constitutive EPSPS transcript abundance by about 7-fold and a basal EPSPS activity approximately 3-fold higher than the S population. Conclusion: The current study reports EPSPS gene duplication for the first time as a mechanism of glyphosate resistance in S. tragus populations. The increase of glyphosate dose needed to kill R1 and R2 plants was linked to the EPSPS transcript abundance and level of EPSPS activity. This evidence supports the convergent evolution of the overexpression EPSPS gene in several Chenopodiaceae/Amaranthaceae species adapted to drought environments and the role of gene duplication as an adaptive advantage for plants to withstand stress.EEA BarrowFil: Yanniccari, Marcos Ezequiel. Instituto Nacional de Tecnología Agropecuaria (INTA). Chacra Experimental Integrada Barrow; ArgentinaFil: Yanniccari, Marcos Ezequiel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina.Fil: Yanniccari, Marcos Ezequiel. Universidad Nacional de La Pampa. Facultad de Agronomía; ArgentinaFil: Palma Bautista, Candelario. Universidad de Córdoba. Department of Agroforestry, Plant Biochemistry and Molecular Biology; EspañaFil: Vázquez García, José G. Universidad de Córdoba. Department of Agroforestry, Plant Biochemistry and Molecular Biology; EspañaFil: Gigón, Ramón. Consultor privado en Control de Malezas; ArgentinaFil: Mallory-Smith, Carol Ann. Oregon State University. Department of Crop and Soil Science; Estados UnidosFil: de Prado, Rafael. Universidad de Córdoba. Department of Agroforestry, Plant Biochemistry and Molecular Biology; Españ

A novel EPSPS Pro-106-His mutation confers the first case of glyphosate resistance in Digitaria sanguinalis

BACKGROUND: Digitaria sanguinalis has been identified as a species at high risk of evolving herbicide resistance, but thus far, there are no records of resistance to glyphosate. This species is one of the most common weeds of summer crops in extensive cropping areas in Argentina. This weed shows an extended period of seedling emergence with several overlapping cohorts during spring and summer, and it is commonly controlled with glyphosate. However, a D. sanguinalis population was implicated as a putative glyphosate-resistant biotype based on poor control at recommended glyphosate doses. RESULTS: The field-collected D. sanguinalis population (Dgs R) from the Rolling Pampas has evolved glyphosate resistance. Differences in plant survival and shikimate levels after field recommended and higher glyphosate doses were evident between Dgs R and the known susceptible (Dgs S) population, and the resistance index was 5.1. No evidence of differential glyphosate absorption, translocation, metabolism, or basal EPSPS activity was found between Dgs S and Dgs R populations; however, a novel EPSPS Pro-106-His point substitution is likely the primary glyphosate resistance endowing mechanism. EPSPS in vitro enzymatic activity demonstrated that an 80-fold higher concentration of glyphosate is required in Dgs R to achieve similar EPSPS activity inhibition as in the Dgs S population. CONCLUSION: This study reports the first global case of glyphosate resistance in D. sanguinalis. This yet novel transversion at the second position of the EPSPS 106 codon demonstrates the intensity of glyphosate pressure in selecting unexpected glyphosate resistance alleles if they retain EPSPS functionality.EEA BarrowFil: Yanniccari, Marcos Ezequiel. Instituto Nacional de Tecnología Agropecuaria (INTA). Chacra Experimental Integrada Barrow; ArgentinaFil: Yanniccari, Marcos Ezequiel. Consejo Nacional de Investigaciones Científicas y Técnicas. Laboratorio de Biotecnología y Genética Vegetal; Argentina.Fil: Yanniccari, Marcos Ezequiel. Universidad Nacional de La Pampa. Facultad de Agronomía; ArgentinaFil: Vázquez García, José G. Universidad de Córdoba. Department of Agroforestry, Plant Biochemistry and Molecular Biology; EspañaFil: Gigón, Ramón. Consultor privado en Control de Malezas; ArgentinaFil: Palma Bautista, Candelario. Universidad de Córdoba. Department of Agroforestry, Plant Biochemistry and Molecular Biology; EspañaFil: Vila Aiub, Martin Miguel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; Argentina.Fil: Vila Aiub, Martin Miguel. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; Argentina.Fil: de Prado, Rafael. Universidad de Córdoba. Department of Agroforestry, Plant Biochemistry and Molecular Biology; Españ

Changes in Weed Communities of Spring Wheat Crops of Buenos Aires Province of Argentina

During 2004 to 2008, weed surveys were conducted in 373 wheat fields of two different cropped areas (southwest [SW] and southeast [SE]) of the southern region of Buenos Aires Province of Argentina where different weed communities were expected because of changes in cropping practices over time, including tillage, crop sequence, fertilizers, and herbicides applied. Weed communities differed between regions, with greater numbers of native species for the SW. Weed community diversity was also greater for the SW region, probably due to the more diverse land use that resulted in greater landscape heterogeneity. Rush skeletonweed, sand rocket, yellow starthistle and turnipseed occurred at higher constancy (proportion of fields in which a given species is present) in the SW region, whereas common chickweed, false bishop's weed, corn speedwell, and common lambsquarters were present more frequently in the SE region. Compared with the 1982 survey, constancy of weeds increased, but those species with high constancy in 1982 were also with high constancy in the recent surveys. Diversity (species richness) was greater in conventional than in a no-tillage system. The constancy of Italian ryegrass, sand rocket, and yellow starthistle was lower under no-till than conventional tillage. Surveys allow identification of changes in weed community related to different agricultural systems. Rotation of crops and livestock avoid the homogenization of the environment at the landscape level. Management strategies will be necessary to prevent the increase of weeds populations' size, preserving plant diversity and the properties of the agroecosystem.EEA BordenaveFil: Scursoni, Julio Alejandro. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Producción Vegetal; ArgentinaFil: Gigón, Ramón. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bordenave; ArgentinaFil: Martin, Andrés Nelson. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Producción Vegetal; Argentina.Fil: Vigna, Mario Raúl. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bordenave; ArgentinaFil: Leguizamon, Eduardo Sixto. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias. Cátedra de Malezas; ArgentinaFil: Istilart, Carolina Maria. Instituto Nacional de Tecnología Agropecuaria (INTA). Chacra Experimental Integrada Barrow; ArgentinaFil: López, Ricardo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bordenave; Argentin

Impact of Imazamox and Imazapyr Carryover on Wheat, Barley, and Oat

Imazapyr and imazamox are frequently applied postemergence to control grass and broadleaf weeds in imidazolinone-resistant sunflower in Argentina. Herbicide carryover to rotational crops represents a disadvantage of these herbicides, particularly in regions with low rainfall during the months prior to rotational crop sowing. Between 2009 and 2012, field and greenhouse studies were conducted on four important sunflower-cropped areas of Argentina. The objective was to quantify the effects of imazapyr alone and imazamox plus imazapyr applied in sunflower crops on the subsequent establishment, growth, and yield of barley, oat, and wheat. In all field experiments, imazapyr alone and imazamox plus imazapyr were applied at recommended rates (80 gha–1 and 66 plus 30 gha–1, respectively), and also, in some experiments, at double the recommended rates. Soil bioassays were also conducted in the greenhouse to study the effect of these herbicides on barley, oat, and wheat seedlings. The mixture of imazamox plus imazapyr was safer for rotational crops than imazapyr applied alone, because of the reduced rate of imazapyr in the mixture treatments. Barley was more sensitive to imidazolinones, particularly imazapyr, than the other winter cereals. Imazapyr at double rate (160 gha–1) reduced barley yield by 45% when seeds were sown 165 d after herbicide application and with 240 mm rainfall after herbicide application.EEA AnguilEEA BordenaveEEA BarrowEEA Hilario AscasubiFil: Scursoni, Julio Alejandro. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Producción Vegetal; ArgentinaFil: Montoya, Jorgelina Ceferina. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Anguil; ArgentinaFil: Vigna, Mario Raúl. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bordenave; ArgentinaFil: Gigón, Ramón. Instituto Nacional de Tecnología Agropecuaria (INTA). Chacra Experimental Integrada Barrow; ArgentinaFil: Istilart, Carolina Maria. Instituto Nacional de Tecnología Agropecuaria (INTA). Chacra Experimental Integrada Barrow; ArgentinaFil: Renzi Pugni, Juan Pablo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Hilario Ascasubi; Argentina.Fil: López, Ricardo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bordenave; ArgentinaFil: Porfiri, Carolina. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Anguil; Argentin

Modeling Avena fatua seedling emergence dynamics: an artificial neural network approach

Avena fatua is an invasive weed of the semiarid region of Argentina. Seedling emergence patterns are very irregular along the season showing a great year-to-year variability mainly due to a highly unpredictable precipitation regime. Non-linear regression techniques are usually unable to accurately predict field emergence under such environmental conditions. Artificial Neural Networks (ANNs) are known for their capacity to describe highly non-linear relationships among variables thus showing a high potential applicability in ecological systems. The objectives of the present work were to develop different ANN models for A. fatua seedling emergence prediction and to compare their predictive capability against non-linear regression techniques. Classical hydrothermal-time indices were used as input variable for the development of univariate models, while thermal-time and hydro-time were used as independent input variables for developing bivariate models. The accumulated proportion of seedling emergence was the output variable in all cases. A total of 528 input/output data pairs corresponding to 11 years of data collection were used in this study. Obtained results indicate a higher accuracy and generalization performance of the optimal ANN model in comparison to non-linear regression approaches. It is also demonstrated that the use of thermal-time and hydro-time as independent explanatory variables in ANN models yields better prediction than using combined hydrothermal-time indices in classical NLR models. The best obtained ANN model outperformed in 43.3% the best NLR model in terms of RMSE of the test set. Moreover, the best obtained ANN predicted accumulated emergence within the first 50% of total emergence 48.3% better in average than the best developed NLR model. These outcomes suggest the potential applicability of the proposed modeling approach in weed management decision support systems design.EEA BordenaveFil: Chantre Balacca, Guillermo Ruben. Universidad Nacional del Sur. Departamento de Agronomía; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiárida; ArgentinaFil: Blanco, Anibal Manuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; ArgentinaFil: Lodovichi, Mariela Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiárida; Argentina. Universidad Nacional del Sur. Departamento de Agronomía; ArgentinaFil: Bandoni, Jose Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; ArgentinaFil: Sabbatini, Mario Ricardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiárida; Argentina. Universidad Nacional del Sur. Departamento de Agronomía; ArgentinaFil: López, Ricardo Luis. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bordenave; ArgentinaFil: Vigna, Mario Raúl. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bordenave; ArgentinaFil: Gigón, Ramón. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bordenave; Argentin