Revista de la Facultad de Ciencias Agrarias
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Sequential application of herbicide options for controlling Conyza sumatrensis in soybean pre-sowing
Get PDFThe aim of this study was to evaluate the efficacy of sequentially applied herbicides to control Conyza sumatrensis, one of the most widely distributed weeds worldwide, in soybean pre-sowing burndown. The study was conducted under field conditions in the state of Paraná, Brazil, at 2018-2019 growing season. The experiment consisted of a randomized block design with four replicates, with 12 treatments consisting of different herbicide mixtures applied before sowing. Control of C. sumatrensis, injury to soybean plants, and variables related to agronomic performance were evaluated. The control levels were high for all treatments, except for the one that was free of saflufenacil in either of the two applications. These results highlight the importance of saflufenacil in the control of C. sumatrensis and show promise for the use of saflufenacil/imazethapyr when considering the system and other weeds. All studied treatments were selective to soybean, which showed higher injury values in the presence of diclosulam; however, this did not compromise the agronomic performance of soybean.
Highlights
• Application of systemic herbicides with sequential application of burndown herbicides, is essential for the control of Conyza sumatrensis (>15 cm height).• Saflufenacil, flumioxazin, and imazethapyr stand out in the control of Conyza sumatrensis.• Protox and ALS inhibitors can replace paraquat in sequential application with equal efficacy in the control of Conyza sumatrensis.The aim of this study was to evaluate the efficacy of sequentially applied herbicides to control Conyza sumatrensis, one of the most widely distributed weeds worldwide, in soybean pre-sowing burndown. The study was conducted under field conditions in the state of Paraná, Brazil, at 2018-2019 growing season. The experiment consisted of a randomized block design with four replicates, with 12 treatments consisting of different herbicide mixtures applied before sowing. Control of C. sumatrensis, injury to soybean plants, and variables related to agronomic performance were evaluated. The control levels were high for all treatments, except for the one that was free of saflufenacil in either of the two applications. These results highlight the importance of saflufenacil in the control of C. sumatrensis and show promise for the use of saflufenacil/imazethapyr when considering the system and other weeds. All studied treatments were selective to soybean, which showed higher injury values in the presence of diclosulam; however, this did not compromise the agronomic performance of soybean.
Highlights
• Application of systemic herbicides with sequential application of burndown herbicides, is essential for the control of Conyza sumatrensis (>15 cm height).• Saflufenacil, flumioxazin, and imazethapyr stand out in the control of Conyza sumatrensis.• Protox and ALS inhibitors can replace paraquat in sequential application with equal efficacy in the control of Conyza sumatrensis
Spatial pattern of mottled stripe disease (Herbaspirillum rubrisubalbicans) in sugar cane
Get PDFSugar cane (Saccharum spp. hybrids) is the most important agroindustrial crop of the tropics. Recently, sugar cane plants with chlorotic leaf streaking associated with the bacterium Herbaspirillum rubrisubalbicans have been observed. This disease impacts photosynthetic capacity and yield. Characterizing the spatio-temporal behavior of chlorotic mottling using prediction maps is an important element of integrated disease management. Here, we determine the spatial distribution of mottled stripe disease in sugar cane in southeastern Mexico. To do this, we randomly chose and georeferenced 80 points in commercial plots in 2016 and 2017 to determine the disease incidence. We generated an experimental semivariogram based on a predetermined theoretical model and estimated Kriging. The incidence was 2.93% in 2016 and 5.36% in 2017 in varieties ICP-MEX-92-1420, CP-72-2086, ITV-92-373, MEX-79434 and MEX-69-290. The spatial behavior of the bacteria fit the pentaspherical model in 2016 and the spherical model in 2017. Spatial interpolation was validated by Mean Error (ME), Root Mean Square Error (RMSE) and Mean Standardized Prediction Error (MSPE) values near zero, visualized using the generated map. The results will be used to guide management of mottled stripe disease in sugar cane in the affected area.
Highlights
H. rubrisubalbicans can persist from sugar cane growing season to the next and spread from one plot to another by different mechanisms.
The chlorotic mottling of sugar cane showed an aggregate type spatial behavior at the regional level.
The differences in spatial patterns between seasons show the dispersion potential of the disease in this crop system, as well as a latent infestation in the area.
The semivariograms and maps show aggregate behavior of this disease, expressed as different spatial patterns given by the spatial dependence among points and the severity of the effects in each plot.Sugar cane (Saccharum spp. hybrids) is the most important agroindustrial crop of the tropics. Recently, sugar cane plants with chlorotic leaf streaking associated with the bacterium Herbaspirillum rubrisubalbicans have been observed. This disease impacts photosynthetic capacity and yield. Characterizing the spatio-temporal behavior of chlorotic mottling using prediction maps is an important element of integrated disease management. Here, we determine the spatial distribution of mottled stripe disease in sugar cane in southeastern Mexico. To do this, we randomly chose and georeferenced 80 points in commercial plots in 2016 and 2017 to determine the disease incidence. We generated an experimental semivariogram based on a predetermined theoretical model and estimated Kriging. The incidence was 2.93% in 2016 and 5.36% in 2017 in varieties ICP-MEX-92-1420, CP-72-2086, ITV-92-373, MEX-79434 and MEX-69-290. The spatial behavior of the bacteria fit the pentaspherical model in 2016 and the spherical model in 2017. Spatial interpolation was validated by Mean Error (ME), Root Mean Square Error (RMSE) and Mean Standardized Prediction Error (MSPE) values near zero, visualized using the generated map. The results will be used to guide management of mottled stripe disease in sugar cane in the affected area.
Highlights
H. rubrisubalbicans can persist from sugar cane growing season to the next and spread from one plot to another by different mechanisms.
The chlorotic mottling of sugar cane showed an aggregate type spatial behavior at the regional level.
The differences in spatial patterns between seasons show the dispersion potential of the disease in this crop system, as well as a latent infestation in the area.
The semivariograms and maps show aggregate behavior of this disease, expressed as different spatial patterns given by the spatial dependence among points and the severity of the effects in each plot
Caracterización genética de germoplasma de maní cultivado (Arachis hypogaea L.) mediante el empleo de marcadores microsatélites
Get PDFCultivated peanut (Arachis hypogaea L.) is a crop species of great economic importance, native to South America. It is divided into two subspecies and six botanical varieties. Genetically is an allotetraploid with two duplicated genomes. For genetic characterization of this specie, microsatellite marker would be the most appropriate. The aim of this study was to characterize the genetic variation among cultivated peanut genetic resources belonging to the Active Peanut Germplasm Bank of the Instituto Nacional de Tecnología Agropecuaria (INTA). Twenty five accessions were genotyped with 23 microsatellite markers, of which 17 were polymorphic. Seventy five polymorphic amplified fragments were observed with an average of 4.41 alleles per locus and a range of 1 to 9 alleles. The polymorphic information content was ranged from 0.15 to 0.58. The value of average genetic diversity was 0.165. Cluster analysis and principal coordinate analysis showed two groups, one for representative accessions of fastigiata subspecie and another of the hypogaea. Analysis of molecular variance results showed variance within and between subspecies.El maní cultivado (Arachis hypogaea L.), es una especie de gran importancia económica, nativo de América del Sur. Se divide en dossubespecies y seis variedades botánicas. Genéticamente es alotetraploide, constituido por dos juegos genómicos duplicados.El empleo de marcadores microsatélites resulta más apropiado para realizar la caracterización genética de esta especie, puesto que permiten detectar un elevado nivel de polimorfismo. El objetivo del presente trabajo fue caracterizar la diversidad genética existente en las entradas de germoplasma de maní cultivado pertenecientes al Banco Activo de Germoplasma de Maní del Instituto Nacional de Tecnología Agropecuaria (INTA). Veinticinco entradas fueron genotipificadas con 23 marcadores microsatélites, de los cuales,17 resultaron polimórficos. Se observaron 75 fragmentos polimórficos amplificados, con un promedio de 4,41 alelos por locus y un rango de 1 a 9 alelos. El contenido de información polimórfica osciló entre 0,15 y 0,58. El valor de la diversidad genética promedio fue de 0,165. Tanto el análisis de conglomerados como el de coordenadas principales evidenciaron dos grupos, uno formado por los materiales representantes de la subespecie fastigiata y otro por los de la subespecie hypogaea. Los resultados del análisis molecular de la varianza mostraron varianza tanto dentro como entre, las subespecies analizadas
Evaluación del proceso de compostaje de dos mezclas de residuos avícolas
Get PDFChicken production wastes, principally poultry manure (layers) and litter (from chickens for fattening), may impact negatively on the environment, contributing to soil, water and air pollution. Aerobic stabilization through composting is an alternative to reduce contamination. This study aims to evaluate the composting process in two mixtures with different percentages of poultry manure of laying chickens and broiler poultry litter. Two mixtures were composted containing 81% and 70% of poultry wastes for 16 weeks. The analytical parameters were: temperature (T°), pH, electrical conductivity (EC), humidity (H), cationic exchange capacity (CEC), total organic carbon (TOC), amonium (NH4+), nitrate (NO3- ), total nitrogen (TN), soluble carbon soluble (SC) were determined in each treatment. The final compost A and B characteristics were 7,1 - 6,8, CE 3,3 - 2,9 (mS.cm-1), COT 14,8 - 17,9%, NT 0.97 - 0.88%, NH4+ 501 - 144,9 mg kg-1, NO3 - 552,3 -543,0 mg kg-1 respectively. The composting process may be a tool to stabilize poultry wastes, minimizing its environmental damage.Los residuos del sector avícola, principalmente guano (aves ponedoras) y cama de parrilleros (aves de engorde), pueden generar un impacto negativo en el ambiente contribuyendo a la contaminación de suelo, agua y aire. La estabilización aeróbica a través del compostaje es una alternativa de tratamiento para reducir la contaminación. El objetivo de este trabajo fue evaluar el proceso de compostaje en dos mezclas con diferentes porcentajes de residuos avícolas (guano de aves ponedoras y cama de pollos parrilleros). Se compostaron dos mezclas que contenían 81% y 70% de residuos avícolas durante 16 semanas. Las variables analizadas fueron: temperatura (T°), pH, conductividad eléctrica (CE), humedad (H), capacidad de intercambio catiónico (CIC), carbono orgánico total (COT), amonio (NH4+), nitrato (NO3 - ), nitrógeno total (NT ) y carbono soluble (CS). Las características finales de los compost A y B fueron: pH 7,1 - 6,8, CE 3,3 - 2,9 (mS. cm- 1), COT 14,8 - 17,9 %, NT 0,97 - 0,88 %, NH4 + 501 - 144,9 mg kg-1, NO3-552,3 - 543,0 mg kg-1 respectivamente. El proceso de compostaje podría ser una herramienta para estabilizar los residuos avícolas minimizando su impacto en el ambiente
Morfología y anatomía floral de Schinopsis balansae (Anacardiaceae)
Get PDFA morphological and anatomical analysis of Schinopsis balansae Engl. was performed, using optical and scanning electron microscopy. The main objective was to obtain data from the flowers of this species, usually described as polygamous-dioecious. The results shows that the flowers described as functionally perfect are structurally pistillate; although have five staminoids, they are smaller and lack sporogenous tissue. In the staminate flowers, the structure described as vestigial pistil is the excrescence of the apex of the receptacle, covered by nectariferous tissue. Thus, it is right to describe S. balansae as dioecious species. The study of the vascularization of male flowers shows that the reduction process is complete, since not even the vascular traces for the pistil persists. The gynoecium of pistillate flowers is pseudomonomerous with one functional carpel, one ovule and one dorsal style and stigmata, and two vestigial carpels, represented only by individual lateral style/stigma. Both types of flowers present an intrastaminal nectary disc, with nectarostomatas for nectar release. The analysis of the anatomic structure of S. balansae provides data that are consistent with those found in other studied genus of Anacardioideae group in the Anacardiaceae family.Se realizó el análisis morfo-anatómico de Schinopsis balansae Engl. con microscopía óptica y electrónica de barrido a fin de obtener datos de las flores de esta especie, definida como polígamo-dioica. Los resultados muestran que las flores estructuralmente perfectas son funcionalmente pistiladas, si bien presentan cinco estaminodios, los mismos carecen de tejido esporógeno; mientras que en las flores estaminadas la estructura denominada pistilo vestigial no es más que la excrecencia del ápice del receptáculo, cubierta por tejido nectarífero. De este modo, lo correcto es describir S. balansae como especie dioica. El estudio de la vascularización de las flores estaminadas muestra que el proceso de reducción es completo, ya que ni siquiera persisten los haces vasculares del pistilo. El gineceo de las flores pistiladas es pseudomonómero, con un carpelo funcional, un estilo/estigma dorsal y un óvulo; además posee dos carpelos vestigiales representados por sendos estilo/estigma laterales. Ambos tipos de flores presentan un disco nectarífero intraestaminal, con nectarostomatas para la salida del néctar. El análisis de la estructura anatómica de S. balansae brinda datos que concuerdan con los encontrados en otros géneros estudiados de la subfamila Anacardioideae de la familia Anacardiaceae
Análisis de los factores explicativos de la rentabilidad de las empresas vinícolas de Castilla-La Mancha
Get PDFThe wine sector in recent decades is experiencing a vertiginous process of changes and new dynamics that are affecting the performance and strategies of firms in the sector: growing internationalization, the fall in the domestic markets of traditional producing countries, the entrance of exogenous capital, etc. The expertise that a given organization demonstrates to adapt to the new situation will be reflected in profitability, the basic indicator for judging efficiency in business management. Starting from a representative sample of firms from Castilla-La Mancha, the greatest wineproducing region in the world, this paper poses a new econometric model consisting of the performance variables defined by the principal component technique. It is inferred from the results that business profitability comes from three variables. First is company structure with greater profitability for capitalist firms than for cooperatives. Second is size where performance is better the larger the size, taking advantage of scale economies. Third is financial structure with greater cost-effectiveness when the firm's make- up prioritizes its own resources and liquidity. On the contrary, the lack of permanent financing to address fixed assets and a trade dynamic orientated toward the sale of low-priced bulk wine significantly reduce profitability ratios.El sector del vino experimenta, en las últimas décadas, un vertiginoso proceso de cambio y nuevas dinámicas, que están afectando el desempeño y estrategias de las empresas del sector: internacionalización creciente, caída de los mercados internos de los países tradicionalmente productores, entrada de capital exógeno, etc. La pericia que muestre la organización para adecuarse a la nueva situación se reflejará en la rentabilidad, indicador básico para juzgar la eficiencia en la gestión empresarial. En este estudio, a partir de una muestra representativa de empresas de Castilla-La Mancha, región española con la mayor dimensión vinícola mundial, se ha planteado un modelo econométrico novedoso integrado por variables de desempeño, definidas con la técnica de componentes principales. De los resultados obtenidos se infiere que la rentabilidad de las empresas proviene de: a) su estructura societaria (mayor si son empresas capitalistas que sociedades cooperativas), b) de su tamaño (mejor desempeño a mayor tamaño, aprovechando economías de escala), y c) estructura financiera (mayor rentabilidad si en la composición de la misma priman los recursos propios y liquidez). Por el contrario, la falta de financiación permanente para hacer frente al activo fijo y una dinámica comercial más orientada hacia las ventas de vino a granel a bajo precio, reducen significativamente los ratios de rentabilidad
Fijación biológica de nitrógeno por cuatro fabáceas en suelos ácidos de Tabasco, México
Get PDFBiological nitrogen fixation is a process that occurs in nature and is the cheapest source of N for humid tropical acid soils. The aim of this study was to quantify the amount of N fixed by species of fabaceae through 15N isotopic techniques, in a savanna soil in Mexico. The treatments were established under a design of a randomized complete block, with four replicates. The variables evaluated were: fresh biomass (FB), dry matter (DM), nodule number (NN), nodule dry mass (NDM), total nitrogen (tN) and biologically fixed nitrogen (fN). Our results show that Mucuna deerengiana L. had higher production of FB and DM (17.50 and 5.47 Mg ha-1), NDM (58.79 mg plant-1) and higher content of tN and fN (526.94 and 522.11 kg ha-1) respectively, compared with Cajanus cajan L., Phaseolus lunatus L. and Sesbania emerus L., species that showed low values in these variables. We conclude that Mucuna deerengiana L. tolerates unfavorable factors prevailing in acid soils and therefore has efficiency greater than 500 kg ha-1 fN; we consider it appropriate to increase the level of nitrogen in savanna soils, without applying chemical fertilizers.La fijación biológica de nitrógeno (FBN) es un proceso que ocurre en la naturaleza y representa la fuente de N más barata para los suelos ácidos del trópico húmedo. El objetivo de este trabajo fue cuantificar la cantidad de N fijado por cuatro especies de fabáceas a través de técnicas isotópicas con 15N, en un suelo de sabana en México. Los tratamientos se establecieron bajo un diseño de bloques completos al azar, con cuatro repeticiones. Las variables evaluadas fueron; biomasa fresca (BF), materia seca (MS), número de nódulos (NN), masa seca de nódulos (MSN), Nitrógeno total (Nt) y Nitrógeno fijado biológicamente (Nf). Los resultados muestran que Mucuna deerengiana L. presentó mayor producción de BF y MS (17,50 y 5,47 Mg ha-1) así como MSN (58,79 mg planta-1) y también mayor contenido de Nt y Nf (526,94 y 522,11 kg ha-1) respectivamente, en comparación con Cajanus cajan L., Phaseolus lunatus L. y Sesbania emerus L., especies que mostraron valores bajos en dichas variables. Se concluye que Mucuna deerengiana L. tolera bien los factores desfavorables que predominan en los suelos ácidos y por ello expresa una eficiencia superior a 500 kg ha-1 de Nf; se considera adecuada para aumentar el nivel de nitrógeno en los suelos de sabana sin aplicar fertilizantes químicos
Convergencia cultural en el consumo mundial de vino
Get PDFThis paper addresses the dynamics of world wine consumption over the past 50 years in 26 countries, verifying whether or not there is a macro-tendency towards a common consumption style, despite differences in taxation, economic policies and distribution systems among countries. From an empirical point of view, the σ and β convergence hypotheses were formally tested. Model results confirm the existence of both types of convergences. Per capita consumption of wine first experienced a reduction in differences between countries and then converged toward a central value. "Traditional" countries, with historically high levels of consumption, showed a decrease in wine consumption, while emerging countries with historically lower consumption levels showed an increase. These findings not only provide further support to the theory of international convergence of wine consumption on a volume basis, as already observed by other researchers in the European market, but they also offer support for the theory in major world markets. Furthermore, convergence appears to be happening not only at a quantitative level but at qualitative level as well, and this phenomenon may very well reflect the changing tastes of worldwide consumers towards a generalized structure of wine consumption.Este paper compara las dinámicas del consumo internacional de vino de los últimos 50 años en 26 países, con el objetivo de averiguar si existe una tendencia global hacia un estilo de consumo común, al margen de las diferencias impositivas y arancelarias, políticas económicas y sistemas de distribución de cada país. Los resultados del modelo confirman las hipótesis de convergencia de tipo σ y de tipo β: se observa una disminución en la diferencia d-el consumo per capita de vino entre países y posteriormente un aumento hacia un valor central, en términos de litros. Los países "tradicionales", con niveles de consumo históricamente altos, han experimentado una disminución del mismo, mientras que países emergentes con menor tradición de consumo de vinos han registrado un crecimiento. Estos resultados no solo apoyan la teoría del consumo internacional del vino desde un punto de vista cuantitativo, ya verificada en mercados europeos, sino que extiende su alcance hacia otros mercados. Se observa también una convergencia cualitativa, fenómeno que podría reflejar un cambio mundial en los gustos de los consumidores hacia un modelo con tendencias a la uniformidad
Influence of genotype-environment interaction on soybean (Glycine max L.) genetic divergence under semiarid conditions
Get PDFThe objective of the present work was to evaluate the influence of the genotype–environment interaction on genetically divergent soybean grown under semiarid conditions. Four experiments were carried out in randomized blocks with four replicates to evaluate twenty-one soybean genotypes. The following descriptors were used to quantify divergence: plant height, dry matter, oil content, number of pods per plant, number of grains per pod, the weight of 100 seeds, yield, days for flowering, and days for maturation. The unweighted pair group method with arithmetic mean was used to group the genotypes from the Mahalanobis distance matrix estimated using the genotypic means estimated by the REML/BLUP method. The grouping of genotypes depended mainly on the effects of the interaction between genotypes and years. The joint analysis, without the effect of the interaction, allowed us to obtain two groups of genotypes. The most recommended crosses were those of the lines BRS Tracajá, BRS Pérola, BRS Carnaúba, M 8644 IPRO, BRS 8590, and BMX OPUS IPRO with the genotype BRS Sambaíba, especially the one between BMX OPUS IPRO and BRS Sambaíba.
Highlights
The grouping of genotypes is dependent on the evaluation conditions, mainly due to the effects of the genotype x years interaction.
The use of estimates of the free genotypic means of the interaction obtained in the joint analysis may be a more adequate alternative to define the heterotic groups and, consequently, the crossings to be performed.
The joint analysis, without the presence of the interaction effect, allows obtaining two groups of genotypes.The objective of the present work was to evaluate the influence of the genotype–environment interaction on genetically divergent soybean grown under semiarid conditions. Four experiments were carried out in randomized blocks with four replicates to evaluate twenty-one soybean genotypes. The following descriptors were used to quantify divergence: plant height, dry matter, oil content, number of pods per plant, number of grains per pod, the weight of 100 seeds, yield, days for flowering, and days for maturation. The unweighted pair group method with arithmetic mean was used to group the genotypes from the Mahalanobis distance matrix estimated using the genotypic means estimated by the REML/BLUP method. The grouping of genotypes depended mainly on the effects of the interaction between genotypes and years. The joint analysis, without the effect of the interaction, allowed us to obtain two groups of genotypes. The most recommended crosses were those of the lines BRS Tracajá, BRS Pérola, BRS Carnaúba, M 8644 IPRO, BRS 8590, and BMX OPUS IPRO with the genotype BRS Sambaíba, especially the one between BMX OPUS IPRO and BRS Sambaíba.
Highlights
The grouping of genotypes is dependent on the evaluation conditions, mainly due to the effects of the genotype x years interaction.
The use of estimates of the free genotypic means of the interaction obtained in the joint analysis may be a more adequate alternative to define the heterotic groups and, consequently, the crossings to be performed.
The joint analysis, without the presence of the interaction effect, allows obtaining two groups of genotypes
Valoración económica de los efectos de la presión antrópica sobre el piedemonte mendocino. Una aplicación de los experimentos de elección discreta
Get PDFIn general, the socioeconomic analysis of natural systems does not enter into the realms of natural science. This paper, however, estimates the human-welfare effects of possible anthropogenic-pressures on the Mendocinian piedmont by a lower provision of environmental services. The discrete choice experiment is applied to elicit the trade-offs in perceived values for three environmental services generated in the basins west of Gran Mendoza (alluvional risk, plant cover, and recreation) and for the costs of programmes designed to mitigate the intensity of such effects. Increased alluvional risk is the anthropogenic-pressure effect on the Mendocinian piedmont that most concerns the population, followed by a decrease of plant cover and recreation. An increase of 1% in alluvional risk is estimated to cost each person, on average, 24.13 pesos (2013 value) yearly in lost welfare, a figure equivalent in social welfare to a decrease of 6% in plant cover. These trade-off values may help policy makers, land managers, and ecologists to consider social preferences in the design of their programmes and activities.En general, el análisis socioeconómico de los sistemas naturales no se contempla en los dominios de la ciencia natural. En este trabajo, sin embargo, se estima el cambio en el bienestar social por los efectos de la presión antrópica sobre el piedemonte mendocino vía la menor provisión de servicios ambientales. Para ello, se utiliza el método de los experimentos de elección discreta para inferir el valor social de tres servicios ambientales generados en las cuencas ubicadas al oeste del Gran Mendoza (riesgo aluvional, cobertura vegetal y recreación) y los costos de programas diseñados para mitigar la intensidad de dichos efectos. Un incremento del riesgo aluvional es el efecto de origen antrópico sobre el piedemonte mendocino que más preocupa a la población, seguido de una disminución de la cobertura vegetal y de la recreación. Se estimó que un incremento del riesgo aluvional en 1% equivale en pérdida de bienestar individual a un gasto, en promedio, de 24,13 pesos, en moneda de 2013, al año, cifra que es equivalente en términos de bienestar a una disminución de 6% de cobertura vegetal. Esta información puede ayudar a los hacedores de políticas, gestores de territorio y ecologistas a tener en cuenta las preferencias sociales en el diseño de sus programas y actividades