Revista de la Facultad de Ciencias Agrarias
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Impact of paclobutrazol on gibberellin-like substances and soluble carbohydrates in pear trees grown in tropical semiarid
Get PDFGiven that Brazilian pear production is unable to meet the annual demand, to consider the possible expansion to non traditional growing regions, turns interesting. Even though under tropical semi-arid conditions pear trees have vigorous vegetative growth, a negative influence on flower bud differentiation and formation affects fruit yield. Our study aimed to evaluate the inhibition efficiency of paclobutrazol (PBZ) on gibberellin biosynthesis, vegetative growth, and carbohydrate production in two pear-treecultivars (‘Santa Maria’ and ‘Hosui’) grown under semi-arid conditions. To this end, two experiments were conducted, one for each pear-tree cultivar. The experimental designs consisted of randomized blocks, with factorial arrangement (5x2x4), corresponding to PBZ doses (0.0, 0.5, 1.0, 1.5, and 2.0 g per linear meter of plant canopy), PBZ application forms (soil and foliar), and evaluation dates (30, 60, 90, and 120 days after application). Both soil and foliar applications inhibited gibberellin biosynthesis in both cultivars, especially after 120 days of application. PBZ affected leaf total soluble carbohydrates and reduced sprout growth in both cultivars. Although PBZ can be potentially used in pear management, further studies are still required to determine specific management practices in tropical semi-arid zones.
Highlights:
Inhibition of gibberellin biosynthesis is more efficient with soil application of paclobutrazol.
Soil application of paclobutrazol results in greater production of carbohydrates.
There is a difference in sensitivity to the effects of paclobutrazol among pear varieties.
The non-application of paclobutrazol results in late maturation of the branches, compromising floral induction.Given that Brazilian pear production is unable to meet the annual demand, to consider the possible expansion to non traditional growing regions, turns interesting. Even though under tropical semi-arid conditions pear trees have vigorous vegetative growth, a negative influence on flower bud differentiation and formation affects fruit yield. Our study aimed to evaluate the inhibition efficiency of paclobutrazol (PBZ) on gibberellin biosynthesis, vegetative growth, and carbohydrate production in two pear-treecultivars (‘Santa Maria’ and ‘Hosui’) grown under semi-arid conditions. To this end, two experiments were conducted, one for each pear-tree cultivar. The experimental designs consisted of randomized blocks, with factorial arrangement (5x2x4), corresponding to PBZ doses (0.0, 0.5, 1.0, 1.5, and 2.0 g per linear meter of plant canopy), PBZ application forms (soil and foliar), and evaluation dates (30, 60, 90, and 120 days after application). Both soil and foliar applications inhibited gibberellin biosynthesis in both cultivars, especially after 120 days of application. PBZ affected leaf total soluble carbohydrates and reduced sprout growth in both cultivars. Although PBZ can be potentially used in pear management, further studies are still required to determine specific management practices in tropical semi-arid zones.
Highlights:
Inhibition of gibberellin biosynthesis is more efficient with soil application of paclobutrazol.
Soil application of paclobutrazol results in greater production of carbohydrates.
There is a difference in sensitivity to the effects of paclobutrazol among pear varieties.
The non-application of paclobutrazol results in late maturation of the branches, compromising floral induction
Cultivo en maceta de Iris xiphium L. (Iris de Holanda) con diferentes concentraciones de humus de lombriz y sus lixiviados
Get PDFSe evaluaron tres variedades de Iris xiphium L. cultivadas en maceta en cuatro proporciones de humus de lombriz y se aplicaron los lixiviados diluidos como bioabono foliar. El experimento se realizó en un diseño completamente al azar con arreglo trifactorial y se midieron ocho variables: longitud de tallo (LT), longitud de botón (LB), longitud de flor (LF), diámetro de botón (DB), diámetro de flor (DF), biomasa (B), área foliar (AF) y días de cosecha (DDC). Los resultados indicaron que la variedad Telstar resultó ser la más precoz. El mejor tratamiento en dicha variedad para las variables LT, LB, B, DF y DDC correspondió a la proporción 30/70 (% lombrihumus / % suelo) y la dilución 1:10 de lixiviado; el segundo mejor tratamiento fue en la variedad Discovery en la proporción 40/60 (%lombrihumus / %suelo) y dilución 1:10 de lixiviado para las variables LT, AF y B. El presente trabajo aporta nueva información en cuanto al uso de sustratos y abono foliar orgánicos para el manejo sustentable, con bajo impacto ambiental, en cultivos florícolas.Se evaluaron tres variedades de Iris xiphium L. cultivadas en maceta en cuatro proporciones de humus de lombriz y se aplicaron los lixiviados diluidos como bioabono foliar. El experimento se realizó en un diseño completamente al azar con arreglo trifactorial y se midieron ocho variables: longitud de tallo (LT), longitud de botón (LB), longitud de flor (LF), diámetro de botón (DB), diámetro de flor (DF), biomasa (B), área foliar (AF) y días de cosecha (DDC). Los resultados indicaron que la variedad Telstar resultó ser la más precoz. El mejor tratamiento en dicha variedad para las variables LT, LB, B, DF y DDC correspondió a la proporción 30/70 (% lombrihumus / % suelo) y la dilución 1:10 de lixiviado; el segundo mejor tratamiento fue en la variedad Discovery en la proporción 40/60 (%lombrihumus / %suelo) y dilución 1:10 de lixiviado para las variables LT, AF y B. El presente trabajo aporta nueva información en cuanto al uso de sustratos y abono foliar orgánicos para el manejo sustentable, con bajo impacto ambiental, en cultivos florícolas
Extracto de semillas de vid (Vitis vinifera L.) con actividad antioxidante: concentración, deshidratación y comparación con antioxidantes de uso comercial
Get PDFLos objetivos de este trabajo fueron: 1) Evaluar un proceso de concentración y deshidratación de un extracto polifenólico de semillas de vid (Vitis vinifera L.). El proceso debía conservar el poder reductor del extracto. 2) Valorar la eficiencia del antioxidante obtenido por comparación con antioxidantes de uso habitual en un producto vegetal susceptible de ser oxidado, tal como el jugo de manzanas. El extracto de semillas de vid fue concentrado a 60°C en un concentrador rotativo al vacío de laboratorio. La concentración de los compuestos fenólicos fue determinada por el método de Folin-Ciocalteu modificado. La actividad antioxidante se determinó midiendo el poder reductor, por el método de Oyaizu. La oxidación del jugo de manzanas se determinó por el método de Özoglu. El extracto concentrado obtenido fue deshidratado por dos métodos: liofilización y secado en lecho de espuma. A igual concentración fenólica, el extracto concentrado mostró mayor capacidad antioxidante que el extracto simple. El extracto secado en lecho de espuma conservó la misma capacidad antioxidante que el extracto concentrado. El extracto liofilizado experimentó una pérdida significativa de la actividad antioxidante. El extracto concentrado de semillas de vid inhibió la oxidación del jugo de manzanas en un 31,51%, el ácido ascórbico en un 2,60% y el dióxido de azufre en un 97,40%.Los objetivos de este trabajo fueron: 1) Evaluar un proceso de concentración y deshidratación de un extracto polifenólico de semillas de vid (Vitis vinifera L.). El proceso debía conservar el poder reductor del extracto. 2) Valorar la eficiencia del antioxidante obtenido por comparación con antioxidantes de uso habitual en un producto vegetal susceptible de ser oxidado, tal como el jugo de manzanas. El extracto de semillas de vid fue concentrado a 60°C en un concentrador rotativo al vacío de laboratorio. La concentración de los compuestos fenólicos fue determinada por el método de Folin-Ciocalteu modificado. La actividad antioxidante se determinó midiendo el poder reductor, por el método de Oyaizu. La oxidación del jugo de manzanas se determinó por el método de Özoglu. El extracto concentrado obtenido fue deshidratado por dos métodos: liofilización y secado en lecho de espuma. A igual concentración fenólica, el extracto concentrado mostró mayor capacidad antioxidante que el extracto simple. El extracto secado en lecho de espuma conservó la misma capacidad antioxidante que el extracto concentrado. El extracto liofilizado experimentó una pérdida significativa de la actividad antioxidante. El extracto concentrado de semillas de vid inhibió la oxidación del jugo de manzanas en un 31,51%, el ácido ascórbico en un 2,60% y el dióxido de azufre en un 97,40%
Pre-germination treatments on Ochetophila trinervis, a native Andean tree with potential use for restoration
Get PDFIn a climate change scenario, global forest loss had a direct impact on the hydrological cycle, making the protection of soil and water resources a central issue. In the Central Andes of western Argentina, information on Chacay (Ochetophila trinervis) mountain forests is scarce. This tree thrives along river and stream banks, fixes atmospheric nitrogen, and grows in impoverished soils. The seeds of O. trinervis are characterized by physical or physiological dormancy, and germination requires technique application. The main goal was to evaluate the effect of mechanical and chemical scarification, cold stratification, and hot water immersion on the final germination percentage, germination speed index, and the mean germination time of O. trinervis seeds. Our results show that mechanical and chemical scarification are the treatments that best inhibit seed dormancy in this species. Mechanical scarification with sandpaper is the treatment that offers a balance between effective results and an easy-to-apply technique. Sulfuric acid (SA) treatment is also efficient in breaking dormancy, but we recommend applying it under extreme careful laboratory conditions.
Highlitghs:
Our findings support the hypothesis that the seeds of O. trinervis show physical dormancy because either mechanical (M) or chemical scarification (SA) techniques achieved the highest germination values.
Our results indicate that mechanical scarification (M) might be a practical option for O. trinervis seedling germination in the Central Andes of Western Argentina.
Sulfuric acid (SA) treatment is also efficient in breaking dormancy, but we recommend applying it under extreme careful laboratory conditions.In a climate change scenario, global forest loss had a direct impact on the hydrological cycle, making the protection of soil and water resources a central issue. In the Central Andes of western Argentina, information on Chacay (Ochetophila trinervis) mountain forests is scarce. This tree thrives along river and stream banks, fixes atmospheric nitrogen, and grows in impoverished soils. The seeds of O. trinervis are characterized by physical or physiological dormancy, and germination requires technique application. The main goal was to evaluate the effect of mechanical and chemical scarification, cold stratification, and hot water immersion on the final germination percentage, germination speed index, and the mean germination time of O. trinervis seeds. Our results show that mechanical and chemical scarification are the treatments that best inhibit seed dormancy in this species. Mechanical scarification with sandpaper is the treatment that offers a balance between effective results and an easy-to-apply technique. Sulfuric acid (SA) treatment is also efficient in breaking dormancy, but we recommend applying it under extreme careful laboratory conditions.
Highlitghs:
Our findings support the hypothesis that the seeds of O. trinervis show physical dormancy because either mechanical (M) or chemical scarification (SA) techniques achieved the highest germination values.
Our results indicate that mechanical scarification (M) might be a practical option for O. trinervis seedling germination in the Central Andes of Western Argentina.
Sulfuric acid (SA) treatment is also efficient in breaking dormancy, but we recommend applying it under extreme careful laboratory conditions
Nutraceutical effects of organic Selenium and vitamin E supplementation on performance, antioxidant protection and egg quality of Japanese quails (Coturnix japonica)
Get PDFThis study evaluated the nutraceutical effects of organic Selenium and vitamin E supplementation on performance, egg quality and antioxidant protection of Japanese quails. Forty-two posture cages with six birds each were randomly set in seven treatments. Each treatment consisted of the addition of 200 IU of vitamin E/kg of feed and increasing levels of organic Selenium. Significant differences were found in α-Tocopherol deposition, enzymatic activity of glutathione peroxidase (GSH-Px) and oxidative bioindicator malondialdehyde (MDA) in egg yolk with vitamin E supplementation. We concluded that supplementing 200mg of vitamin E and 0.30 ppm organic Selenium did not affect bird performance, but improved egg quality and shelf life.
Highlights:
This study evaluated the nutraceutical effects of organic selenium and vitamin E supplementation on egg quality of Japanese quails.
Forty-two posture cages with six birds each were randomly set in seven treatments. Each treatment consisted of the addition of 200 IU of vitamin E/kg of feed and increasing levels of organic selenium.
Supplementing 200mg of vitamin E and 0.30 ppm organic selenium did not affect bird performance, but improved egg quality and shelf life.This study evaluated the nutraceutical effects of organic Selenium and vitamin E supplementation on performance, egg quality and antioxidant protection of Japanese quails. Forty-two posture cages with six birds each were randomly set in seven treatments. Each treatment consisted of the addition of 200 IU of vitamin E/kg of feed and increasing levels of organic Selenium. Significant differences were found in α-Tocopherol deposition, enzymatic activity of glutathione peroxidase (GSH-Px) and oxidative bioindicator malondialdehyde (MDA) in egg yolk with vitamin E supplementation. We concluded that supplementing 200mg of vitamin E and 0.30 ppm organic Selenium did not affect bird performance, but improved egg quality and shelf life.
Highlights:
This study evaluated the nutraceutical effects of organic selenium and vitamin E supplementation on egg quality of Japanese quails.
Forty-two posture cages with six birds each were randomly set in seven treatments. Each treatment consisted of the addition of 200 IU of vitamin E/kg of feed and increasing levels of organic selenium.
Supplementing 200mg of vitamin E and 0.30 ppm organic selenium did not affect bird performance, but improved egg quality and shelf life
Humatos de vermicompost como mitigador de la salinidad en albahaca (Ocimum basilicum L.)
Get PDFBioestimulants of the growth are substances that act as activators of the physiology, absorption of nutrients and to mitigate the stress of salinity. The objective was to evaluate humates of vermicompost as attenuating of the salinity in the emergence and growth of basil (Ocimum basilicum L.). The experimental design was completely randomized with factorial arrangement whose factors were basil varieties (Napoletano and Sweet Genovese), concentrations of NaCl (0.50 and 100 mM) and humates of vermicompost (0 and 1/60 v/v) with six replications. Variance analysis and independent comparisons of means (p ≤ 0.05) were done. The experiment was carried out in 2013 in La Paz, Mexico. The percentage and emergency rate, radicle length, seedling height, fresh and dry biomass of radicle and aerial part were measured. Significant differences were found for all variables (p ≤ 0.05), showing differential response among varieties for emergence rate, emergence percentage and morphometric variables, highlighting the variety Napoletano with biostimulant application as treatment with better results. The humates stimulated all variables under saline conditions, allowing that the tolerant variety improves its emergence and growth and the sensitive variety increases its tolerance to the saline stress.Los bioestimulantes del crecimiento son sustancias que actúan como activadores fisiológicos, absorción de nutrientes y mitigan el estrés salino. El objetivo fue evaluar humatos de vermicompost como atenuantes del efecto de la salinidad en la emergencia y crecimiento de albahaca (Ocimum basilicum L.). El diseño experimental fue completamente al azar con arreglo factorial, cuyos factores fueron variedades de albahaca (Napoletano y Sweet Genovese), concentraciones de NaCl (0, 50 y 100 mM) y humatos de vermicompost (0 y 1/60 v/v) con seis repeticiones. Se realizaron análisis de varianza y comparaciones independientes de medias (p ≤ 0,05). El experimento se realizó en 2013 en La Paz, México. Se midió el porcentaje y tasa de emergencia, longitud de radícula, altura de plántula, biomasa fresca y seca de radícula y de parte aérea. Se encontraron diferencias significativas para todas las variables (p ≤ 0 ,05), mostrando respuesta diferencial entre variedades para tasa, porcentaje de emergencia y variables morfométricas, destacando la variedad Napoletano con aplicación del bioestimulante como el tratamiento con mejores resultados. El uso de humatos estimuló todas las variables en condiciones de salinidad, permitiendo que la variedad tolerante mejore su emergencia y crecimiento y la variedad sensible incremente su tolerancia al estrés salino
Variaciones numéricas de Diaphorina citri Kuwayama (Sternorrhyncha: Psyllidae) y del Ectoparasitoide Tamarixia radiata (Waterston) (Hymenoptera: Eulophidae) en una plantación de naranjos de Entre Ríos, Argentina
Get PDFDiaphorina citri is a vector of the bacterium that produces the HLB disease in citrus, one of the most destructive. In commercial plantations of sweet orange in Entre Ríos analyzed spatialtemporal abundance of D. citri adults and the ectoparasitoid Tamarixia radiata. Fortnightly and in three successive years we collected adults with 10 yellow sticky traps, and data were related to the mean shooting percentage from another plantation. The number of D. citri/trap/ fortnight was analyzed by Kruskal-Wallis and the Mantel test and the aggregation response of T. radiata by correlation. Both populations exhibited greater abundance in the first year: frequent abamectine applications in the second and third years produced a marked abundance reduction. Spatially, D. citri dissimilarity between trees was not associated with their distance, but correlation between the number of D. citri/ trap was significant. Chronologically D. citri exhibited four peaks of abundance associated with winter, spring and summer flush. The greater T. radiata abundance occurred in those trees with greater D. citri abundance, and both species were spatially correlated. The anti clock-wise spiraling in D. citri - T. radiata diagram in single trees suggests a host- parasitoid interaction, structured as local populations.Diaphorina citri es vector de la bacteria que produce la enfermedad HLB en cítricos, una de las más destructivas. En lotes comerciales de naranja dulce en Entre Ríos se analizó la abundancia espacio-temporal de adultos de D. citri y del ectoparasitoide Tamarixia radiata. Quincenalmente y durante tres años se colectaron adultos en 10 trampas cromotrópicas y los datos obtenidos fueron relacionados con el porcentaje medio de brotación de otra plantación. El número de D. citri/trampa/quincena se analizó mediante Kruskal-wallis y prueba de Mantel y la respuesta de agregación de T. radiata mediante correlación. Ambas poblaciones exhibieron la mayor abundancia el primer año: las frecuentes aplicaciones de abamectina en el segundo y tercero provocaron una marcada reducción. Espacialmente, la diferencia numérica de D. citri entre árboles no estuvo asociada a su cercanía pero la correlación entre ellos fue significativa. Temporalmente se evidenciaron cuatro picos de abundancia: tres asociados a brotación (invernal, primaveral y estival), y un cuarto no asociado a brotación. La mayor abundancia de T. radiata ocurrió en los árboles con mayor abundancia de D. citri y hubo una significativa correlación espacial entre ambas especies. El enrollamiento anti-horario del gráfico entre D. citri - T. radiata en árboles individuales sugiere una interacción huésped- parasitoide, estructurada como poblaciones locales
Metallic elements in foliar material and fruits of three tree species as bioindicators
Get PDFThis study aimed to determine the presence of metal elements in fruits and leaves of three tree species as bioindicators in San Luis Potosi, Mexico. Ninety fruit and 90 leaf samples (30 per tree species) were collected at five sites (agricultural, suburban, commercial and services, urban, and mining), using the site and the presence of P. laevigata, S. molle, and A. farnesiana as references. Total concentrations of 13 metal elements were determined using an inductively coupled plasma mass spectrometer (ICP-MS). The species were significantly affected by Co, As, and Pb (ANOVA, p≤0.05). Considering the land use and the species, the contents determined in the leaves and fruits of the three species had sufficient and phytotoxic contents of Al, Cd, Co, Ni, Mn, Ti, and Cr, and excessive ranges with the possible phytotoxic effect of As, Cu, Pb, Zn, V, and Fe. The A. farnesiana had the highest concentrations of 12 heavy metals analyzed (HM). The variation in total metal concentrations between leaves and fruits ranged from 84.70 to 99.06%, with V, As, and Cr being prominent. The functionality of these tree species as phytoremediators and bioindicators is reviewed to evaluate environmental impacts on land use.
Highlights
Tree species represent a potential bioindicator for studying environmental pollutants due to their ability to accumulate heavy metals.
The variation in total metal concentrations between leaves and fruits ranged from 84.70 to 99.06%
The contents determined in the leaves and fruits of the three species trees had sufficient and phytotoxic HM contents.
The tree species have phytoremediators capacity to evaluate environmental impacts and environmental contamination of land use.This study aimed to determine the presence of metal elements in fruits and leaves of three tree species as bioindicators in San Luis Potosi, Mexico. Ninety fruit and 90 leaf samples (30 per tree species) were collected at five sites (agricultural, suburban, commercial and services, urban, and mining), using the site and the presence of P. laevigata, S. molle, and A. farnesiana as references. Total concentrations of 13 metal elements were determined using an inductively coupled plasma mass spectrometer (ICP-MS). The species were significantly affected by Co, As, and Pb (ANOVA, p≤0.05). Considering the land use and the species, the contents determined in the leaves and fruits of the three species had sufficient and phytotoxic contents of Al, Cd, Co, Ni, Mn, Ti, and Cr, and excessive ranges with the possible phytotoxic effect of As, Cu, Pb, Zn, V, and Fe. The A. farnesiana had the highest concentrations of 12 heavy metals analyzed (HM). The variation in total metal concentrations between leaves and fruits ranged from 84.70 to 99.06%, with V, As, and Cr being prominent. The functionality of these tree species as phytoremediators and bioindicators is reviewed to evaluate environmental impacts on land use.
Highlights
Tree species represent a potential bioindicator for studying environmental pollutants due to their ability to accumulate heavy metals.
The variation in total metal concentrations between leaves and fruits ranged from 84.70 to 99.06%
The contents determined in the leaves and fruits of the three species trees had sufficient and phytotoxic HM contents.
The tree species have phytoremediators capacity to evaluate environmental impacts and environmental contamination of land use
Efecto de cadáveres de Galleria mellonella infectados con Heterorhabditis bacteriophora y Steinernema rarum, sus macerados y juveniles infectantes muertos en la supresión de Meloidogyne javanica
Get PDFNematodes of the Meloidogyne genus affect to most of crops of an economic importance in Argentina. Researches related to new control strategies are needed to reduce the damage produced by these organisms. The objective of this work was to compare the effects of Galleria mellonella cadavers infected with the Argentine isolates Heterorhabditis bacteriophora Rama Caída and Steinernema rarum NOE, cadaver macerates and dead infective juveniles (IJs) on M. javanica suppression. Experiments were performed using 24-well plates and pepper plants grown in a growth chamber. The entomopathogenic nematodes-infected G. mellonella cadavers, their cadaver macerates and dead IJs were effective in suppressing M. javanica second-stage juveniles under laboratory conditions. The use of H. bacteriophora-infected cadavers caused a significant decrease in the number of galls and egg masses on pepper plants parasitized by M. javanica, in a growth-chamber.Nematodos del género Meloidogyne afectan a la mayoría de los cultivos de importancia económica en Argentina. Investigaciones relacionadas con nuevas estrategias de control son necesarias para reducir el daño ocasionado por estos organismos. El objetivo de este trabajo fue comparar el efecto de cadáveres de Galleria mellonella infectados con los aislados argentinos Heterorhabditis bacteriophora Rama Caída y Steinernema rarum NOE, sus macerados y juveniles infectantes (JIs) muertos en la supresión de M. javanica. Las experiencias fueron conducidas utilizando placas de cultivo de 24 pozos y plantas de pimiento que crecieron en cámara de crecimiento. Los cadáveres infectados, sus macerados y JIs muertos fueron efectivos en suprimir juveniles de segundo estadio de M. javanica en las experiencias de laboratorio. En cámara de crecimiento, el uso de cadáveres infectados con H. bacteriophora causó reducción en el número de agallas y masas de huevos en plantas de pimiento parasitadas por M. javanica
Primer registro del daño de Leucothrips piercei (Morgan) (Thysanoptera: Thripidae) en cultivos de pimiento (Capsicum annuum L.) (Solanaceae) en la Argentina
Get PDFLeucothrips piercei (Morgan) is newly recorded from Argentina and Capsicum annuum L. is registered as a new host plant. The diagnostic characters are described and the characteristics of the damage to the leaves of pepper are provided.Se cita por primera vez para la Argentina la presencia de Leucothrips piercei (Morgan) y se registra a Capsicum annuum L. como una nueva planta huésped. Se describen los caracteres diagnósticos y se detallan las características del daño ocasionado a las hojas de pimiento