Investigación Agraria

Morphologic and physicochemical characterization of the fruits of mandarin 'Okitsu', 'Marisol' and tangor 'Ortanique'

RESUMO O presente trabalho teve por objetivo avaliar a qualidade morfológica, física e química dos frutos das tangerineiras Satsuma 'Okitsu' pertencente ao Grupo das Satsumas (Citrus unshiu Marcovitch), e 'Marisol', pertencente ao Grupo das Clementinas (Citrus clementina Hort. ex Tanaka) e do tangoreiro 'Ortanique' [C. sinensis (L.) Osbeck X C. reticulata Blanco]. O trabalho foi realizado na Coleção de Citros do Polo de Modernização Tecnológica do Médio Alto Uruguai (PMTec) localizado no município de Frederico Westphalen, RS. Foram realizadas análises para avaliação do tamanho, densidade, porcentagem de suco dos frutos, índices de maturação no suco dos frutos (pH, sólidos solúveis totais, acidez total titulável e relação sólidos solúveis totais/acidez total titulável ou ratio), e os teores de ácido ascórbico (Vitamina C). Os dados foram comparados pelo teste de Tukey a p<0,05. O tangor 'Ortanique' apresentou teores de sólidos solúveis totais, acidez total titulável e ratio, significativamente superior às tangerinas. A tangerina 'Marisol' apresentou maior teor de ácido ascórbico. Os resultados mostraram-se promissores, pois, as tangerineiras 'Okitsu', e 'Marisol' e o tangoreiro 'Ortanique', nas safras 2013 e 2014, apresentaram características de sabor dos frutos dentro da faixa de resultados encontrados para outros híbridos e tangerinas produzidas em outras regiões do Brasil. Desta maneira poderão oferecer como alternativas aos citricultores desta região, ampliando ainda mais o período de colheita de tangerinas e híbridos sem sementes.

ABSTRACT This work aimed to evaluate the morphological, physical and chemical quality of fruits of the mandarin Satsuma 'Okitsu', which belongs to the Group of Satsumas (Citrus unshiu Marcovitch), the mandarin 'Marisol', which belongs to the Group of Clementines (Citrus clementina Hort. ex Tanaka) and the tangor 'Ortanique' [C. sinensis (L.) Osbeck x C. reticulata Blanco]. The study was carried out at the Citrus Collection of the Polo of Technological Modernization from the Medio Alto Uruguay, located in Frederico Westphalen, State of Rio Grande do Sul, Southern Brazil. Analyses were performed to assess the size, density, percentage of juice of the fruits, maturation rates in the fruit juice (pH, total soluble solids, titulabre total acidity and relation between total soluble solids/ titulabre total acidity or ratio), and the ascorbic acid content (Vitamin C). Data were compared by Tukey test at p<0.05. The tangor 'Ortanique' showed total soluble solids, titulabre total acidity and ratio significantly higher than the mandarines. The mandarin 'Marisol' showed higher ascorbic acid content. The results were promising, because the mandarin 'Okitsu' and 'Marisol' and the tangor 'Ortanique' yielded in 2013 and 2014 showed that the fruit flavor characteristics were within the range founded to other hybrid and mandarins produced in other regions of Brazil. In this way they will be offered as alternatives to citrus growers in this region, further extending the harvest period of mandarins and seedless hybrids.

Evaluación agronómica de cinco variedades de maní de porte semi erecto en dos localidades del Chaco Central

RESUMEN El maní es una excelente alternativa agrícola para los pequeños agricultores del Chaco Central, debido a su valor nutritivo y adaptación a climas semiáridos. El trabajo de investigación fue realizado entre enero y junio de 2013 en la Chacra Experimental Isla Poí del Servicio Agropecuario de la Sociedad Cooperativa Chortitzer Ltda., distrito de Loma Plata (22°29'38,7'' Sur y 59°43'53,2'' Oeste), Departamento de Boquerón y en una finca de productor del distrito Teniente Irala Fernández (22°58'20,9'' Sur y 59°31'42,8'' Oeste), Departamento de Presidente Hayes, Paraguay, con el objetivo de evaluar el desempeño agronómico de cinco variedades de maní de porte semi erecto. El diseño experimental fue de bloques completos al azar con arreglo factorial 2 x 5, con cuatro repeticiones. Los factores estuvieron constituidos por las dos localidades (Isla Poí y Teniente Irala Fernández) y las cinco variedades (Pytá, Negrito, Moroti, Rosado y Tatú IAC), considerando las variables rendimiento con cáscara y sin cáscara, porcentaje de cáscara y masa de mil granos. Los datos obtenidos fueron sometidos al análisis de varianza y las medias comparadas por el test de Tukey al 5% de probabilidad de error. No hubo interacción entre los factores para ninguna de las características estudiadas. Se encontró significancia entre localidades para las variables evaluadas, a excepción del porcentaje de cáscara. En Teniente Irala Fernández el rendimiento de granos y la masa de mil granos fue de 25,74% y 31,11%, superior al de Isla Poí. Entre variedades hubo diferencias solo en masa de mil granos, donde Pytá (503,62 g) fue superior a Negrito (423,50 g). El rendimiento de granos estuvo entre 1,39 t ha-1 (Negrito) y 1,79 t ha-1 (Pytá) indicando que el cultivo del maní es una alternativa agronómicamente viable para las condiciones del Chaco Central paraguayo.

ABSTRACT Peanuts are an excellent agricultural alternative for farmers from Chaco Central because of its nutritional value and adaptability to semiarid climates. The research was conducted between January and June 2013, at the Chacra Experimental Isla Poí from the Servicio Agropecuario of the Cooperative Society Chortitzer Ltda., district of Loma Plata (22° 29' 38.7 '' South and 59° 43'53.2'' West), Department of Boquerón and on a farm producer from the district of Teniente Irala Fernández (22° 58' 20,9 '' South and 59° 31' 42,8 '' West), Department of Presidente Hayes, Paraguay, in order to evaluate the agronomic performance of five varieties of semi erect peanut. The experimental design was randomized complete blocks with factorial arrangement 2 x 5, with four replicates. The factors were constituted by the two localities (Isla Poí and Teniente Irala Fernández) and the five varieties (Pytá, Negrito, Moroti, Rosado and Tatú IAC), considering the variables yield with shell and without shell, percentage of shell and mass of thousand grains. The data obtained were subjected to analysis of variance and the means compared by Tukey test at 5% probability of error. There was no interaction between factors for any of the characteristics studied. Significance between locations for the variables evaluated was found, except for the percentage of shell. In Teniente Irala Fernandez grain yield and mass of a thousand grain was 25.74% and 31.11%, higher than in Isla Poí. Among varieties there were differences in the mass of one thousand grains where Pytá (503.62 g) was superior to Negrito (423.50 g). Grain yield ranged from 1.39 t ha-1(Negrito) and 1.79 t ha-1 (Pytá), indicating that the cultivation of peanuts is an agronomical alternative for the conditions of Paraguayan Central Chaco.

Análisis de la variabilidad espacial de la rentabilidad del cultivo de soja en una propiedad del Distrito de Villeta - Departamento Central

RESUMEN El objetivo de la investigación fue crear un mapa de la variabilidad espacial de la rentabilidad de la soja, a través de datos de productividad del cultivo, a fin de analizar la viabilidad económica del mismo. El trabajo se realizó durante la zafra 2014/2015, en la agro-ganadera Querencia (Villeta-Central). La variedad de soja utilizada fue Syn 1161RR. La implantación del cultivo fue en una superficie de 21,03 ha, en un sistema de siembra directa, donde la fertilización, control de malezas, enfermedades y plagas fueron realizadas de acuerdo con las recomendaciones y necesidades del cultivo. Para la obtención de la rentabilidad, primeramente, fue determinada la productividad del cultivo a través de un muestreo en malla, de modo a proporcionar el mayor número de puntos posibles para la caracterización del área. La localización y distribución geográfica de los puntos de muestreo se efectuó con un receptor GPS-Trimble. Se realizó un análisis exploratorio y análisis geoestadístico de los datos, a fin de la determinación de la dependencia espacial y generación de los mapas. La creación de un mapa de lucratividad, a partir de datos de la productividad, se mostró adecuada, permitiendo observar la variabilidad espacial del lucro, cuando comparado con el promedio del área, lo que permitió contar con una información precisa de la viabilidad económica del cultivo bajo esas condiciones. La productividad promedio fue de 3.753,33 kg ha-1, superior a la media nacional, donde el 71,95% del área presentó un rendimiento de 2.403,11 a 4.267,17 kg ha-1, con una rentabilidad de 409,93 a 969,15 US$ ha-1.

ABSTRACT The aim of the research was to create a map of the spatial variability of the yield of soybean, through crop productivity data, in order to assess the economic viability of the crop. The work was conducted during the 2014/2015 harvest on the farm Querencia (Villeta-Central). The soybean variety used was Syn 1161RR. The implementation of the crop was in an area of 21.03 ha, in a system of direct seeding, where fertilization, weed control, pests and diseases were carried out in accordance with the recommendations and requirements of the crop. To obtain the yield, productivity was determined first, through mesh sampling, to provide the greatest possible number of points for the characterization of the area. The location and geographical distribution of the sampling points were performed with a Trimble GPS-receiver. An exploratory analysis and geostatistical analysis of the data were carried out in order to determine the spatial dependence and generation of maps. The elaboration of a profitability map, from productivity data, was adequate, allowing observing the spatial variability of profit, when compared to the average for the area, which allowed obtaining precise information of the economic viability of cultivation under these conditions. The average productivity was 3.753.33 kg ha-1, higher than the national average, where 71.95% of the area presented a yield of 2.403.11 to 4267.17 kg ha-1, with a profit of 409.93 to 969.15 US$ ha-1.

Influence of doses and of two sources of potassium in the maize root system and in the electrical conductivity in the soil

RESUMO Atualmente vários programas de fertilização recomendam aplicação de altas doses de potássio, com cloreto de potássio (KCl) como principal fonte, apresentando alto poder salino, existindo alternativas de adubação potássica que podem apresentar menor efeito no solo. O presente trabalho teve como objetivo avaliar o efeito de diferentes doses de KCl e K-UP(r) no sistema radicular do milho e na condutividade elétrica no solo. O experimento foi conduzido em ambiente protegido no município de Minga Guazú, Departamento de Alto Paraná, Paraguai, no período de janeiro de 2016. Foi utilizado o delineamento fatorial inteiramente casualizado, envolvendo duas fontes de K, quatro doses, uma localização do fertilizante em relação às sementes e quatro repetições. As doses consistiram em equivalentes a 0, 50, 100 e 150 kg ha-1 de K2O, posicionadas lateralmente a 0,03 m da linha de semeadura. O solo foi acondicionado em caixas plásticas com 0,40 m de comprimento x 0,20 m de largura x 0,13 m de altura, e procedeu-se a semeadura do milho e adição do KCl e K-UP(r). A umidade do solo mantida em 80% do teor de água na capacidade de campo desde a semeadura até germinação. Em cada tratamento foi avaliado a massa seca de raízes e condutividade elétrica do solo. Os resultados mostram que indiferente das fontes de K utilizada estas causam aumento na condutividade elétrica do solo. O K-UP(r) obteve os menores valores de condutividade elétrica e com o aumento da dose não ocorreu maior decréscimo na massa seca da raiz diferente do observado em relação ao KCl.

ABSTRACT Currently various fertilization programs recommends the application of high doses of potassium, with potassium chloride (KCl) as the main source, presenting a high salt power, existing potassium fertilization alternatives that may have less effect on the soil. This study aimed to evaluate the effect of different doses of KCl and K-UP(r) in the maize root system and in the electrical conductivity in the soil. The experiment was conducted in a protected environment in Minga Guazú, Department of Alto Paraná, Paraguay, in January, 2016. The experimental design was completely randomized factorial, involving two sources of K, four doses, one fertilizer location regarding seeds, and four replications. The doses consisted of equivalent of 0, 50, 100 and 150 kg ha-1 K2O, laterally positioned at 0,03 m from the planting line. The soil was packed in plastic boxes with dimensions of 40 cm length x 20 cm width x 13 cm of height, and then the sowing of maize and the addition of KCl and K-UP(r) was made. Soil moisture was maintained in 80% of the water content at field capacity from seeding to germination. In each treatment dry mass of roots and soil electrical conductivity was evaluated. The results show that regardless of the sources of K used, these cause an increase in the electrical conductivity of the soil. The K-UP(r) obtained the lowest values of electrical conductivity and with the increase of the dose did not occurred a greater decrease in the dry mass of the root different from that observed in relation to KCl.

Desempeño productivo, calidad de la canal y de la carne de corderos enteros y castrados alimentados en sistema de creep-feeding

RESUMEN El presente estudio fue realizado con el objetivo de determinar el desempeño productivo, calidad de la canal y de la carne de corderos enteros y castrados alimentados en un sistema de Creep-Feeding. El trabajo experimental constó de tres partes, la fase de evaluación del desempeño productivo se realizó en la cabaña Don Vicente ubicada en el distrito de Valenzuela, Departamento de Cordillera, la evaluación del rendimiento de la canal se efectuó en un frigorífico comercial ubicado en la ciudad de Luque, Departamento Central y la valoración de la calidad de carne se desarrolló en el laboratorio de carne del Departamento de Producción Animal, Facultad de Ciencias Agrarias, Universidad Nacional de Asunción. El trabajo de campo comenzó el 26 de setiembre del 2013 y finalizó el 13 enero del 2014. Han sido objeto de estudio 40 corderos machos cruce Dorper × Santa Inés con 15 ± 3 días de edad y pesos de 11,288 ± 1,33 kg. El diseño experimental fue completamente al azar y tuvo dos tratamientos y 20 repeticiones, cada unidad experimental constituyó un cordero. Los tratamientos fueron T1: Corderos Enteros y T2: Corderos Castrados, lo corderos fueron sometidos a una suplementación al pie de la madre (Creep-Feeding). Las variables evaluadas fueron, desempeño productivo medidos al inicio y luego cada 15 días constituyéndose siete periodos para determinar Ganancia Diaria de Peso (GDP), y Ganancia Total de Peso (GTP); al finalizar el estudio de comportamiento productivo los corderos fueron faenados y se evaluó el rendimiento de la canal caliente, merma de la res fría, marmoreo del musculo Longissimus dorsi, espesor de grasa dorsal, perdidas por cocción y terneza. Los datos fueron analizados mediante comparación de medias pruebas t de Student, adoptándose un nivel de error de 5%. También fue utilizado un análisis de regresión para determinar la tendencia del crecimiento de los animales. No se observaron diferencias estadísticas significativas para GDP, GTP, rendimiento de la canal, pérdida por cocción y fuerza de corte, entre animales enteros y castrados, no obstante en el espesor de grasa dorsal se presentó diferencia estadística a favor del tratamiento de corderos castrados.

ABSTRACT The present study was carried out to determine the productive performance, quality of the carcass and the meat of entire and castrated lambs fed on a Creep-Feeding system. The experimental work consisted of three parts: the productive performance evaluation phase was carried out on the farm Don Vicente located in the district of Valenzuela, Department of Cordillera, the evaluation of the carcass yield was carried out in a commercial refrigerator located in Luque, Central Department; and the evaluation of meat quality was developed in the meat laboratory of the Department of Animal Production, Faculty of Agrarian Sciences - National University of Asunción.Fieldwork began on September 26, 2013 and ended on January 13, 2014. Forty male Dorper × Santa Ines lambs have been studied, with 15 ± 3 days of age and weights of 11,288 ± 1,33 kg. The experimental design was completely random and had two treatments and 20 repetitions; each lamb was considered an experimental unit. The treatments were T1: Entire Lambs and T2: Castrated Lambs. The lambs were supplemented at the foot of the mother (Creep-Feeding). The evaluated variables were, productive performance measured at the beginning and then every 15 days constituting seven periods to determine Average Daily Gain (ADW) and Total Weight Gain (TWG); at the end of the study of productive behavior, the lambs were slaughtered and the hot carcass yield, cold shedding, marbling of the Longissimus dorsi muscle, dorsal fat thickness, cooking losses and tenderness were evaluated. The data were analyzed by comparison of means by Student's t-tests, adopting an error level of 5%. A regression analysis was also used to determine the growth trend of the animals. No statistically significant difference was observed for ADW, TWG, carcass yield, cooking loss and shear strength, between entire and castrated animals, although in the dorsal fat thickness there was a significant difference in favor of castrated lambs.

Height and productivity of Urochloa brizantha in different seasons and cutoff frequencies

RESUMO A produção de carne bovina depende basicamente da produção de pastagens, assim, o objetivo dessa pesquisa foi avaliar a altura do dossel e as produções de matéria seca de lâminas foliares e colmo do capim Urochloa brizantha cv. Piatã em função das frequências de cortes, estações do ano com e sem irrigação. O delineamento foi inteiramente casualizado em esquema fatorial 4x2x3, sendo quatro idades de corte (21, 28, 35 e 42 dias entre cortes), irrigado e não irrigado, e três estações do ano (outono, inverno e primavera) com seis repetições por tratamento (canteiros experimentais). Os parâmetros avaliados foram: altura de dossel e as produções de massa seca total de lâminas foliares e colmo. Os resultados indicaram que na primavera, as maiores alturas do dossel foram registradas em pastos cortados aos 28 dias com 39,6 cm de altura. As produções de massa seca de lâminas foliares foram maiores no intervalo de corte de 42dias, sendo as maiores produções durante o Outono com 1,364 kg ha-1 com irrigação. A primavera foi à estação que apresentou as melhores produções de massa seca de colmos com 0,141 kg ha-1 de MS aos 42 dias sem irrigação. A irrigação aumenta a altura do dossel durante o inverno. Estas informações podem ser recomendadas na alimentação de animais ruminantes.

ABSTRACT The beef production depends basically on the production of pastures, thus the main goal of this research was to evaluate the dossal height and dry matter production of leaf blades and grass stalk Urochloa brizantha cv. Piatana depending on cutoff frequency, seasons and irrigation. The experimental design used was completely randomized in factorial scheme (4x2x3) with four cutoff frequencies (21, 28, 35 and 42 days between cuts) irrigated and non-irrigated, and three seasons (fall, winter and spring) with six repetitions per treatment (experimental plots). The parameters evaluated were: dossal height and total dry mass production of leaf blades and stem. The results showed: in spring season, the highest of the dossal were observed in pastures cut to 28 days with 39.6 cm. The dry mass production of leaf blades was higher at 42 days cutting, with the largest production (1.364 kg ha-1) in autumn with irrigation. In spring season without irrigation was the best dry matter production of stalks with 0.141 kg ha-1 at 42 days. The dossal height increases with irrigation in winter. This information may be recommended in the feeding of ruminant animals.

Characterization of the Maximum Density of the soil, Region Paraná Midwest

RESUMO A susceptibilidade do solo à compactação, avaliada pelo ensaio Proctor, é uma medida que vem sendo estudada nos sistemas agrícolas de produção visando um estudo mais detalhado sobre o grau de compactação que é possível obter em um determinado solo. O presente trabalho teve objetivo comparar diferentes locais, (Guarapuava, Pinhão e Candói) em diferentes profundidades (0-10; 10-20 e 20-40 cm para Guarapuava, 0-10; 10-25 e 25-40 cm para Pinhão e 0-15; 15-25 e 25-40 cm para Candói) quanto à densidade máxima destes solos. As amostras foram submetidas ao ensaio Proctor normal, determinando-se a densidade máxima e a umidade crítica para compactação. O acúmulo de matéria orgânica na camada superficial dos solos proporcionou uma redução da densidade máxima e aumentou a umidade crítica para compactação do solo, aumentando a compactação conforme há um aumento na profundidade.

ABSTRACT The susceptibility of soil to compaction, evaluate by the Proctor test, is a measure that has been studied in agricultural production systems, aiming at a more detailed study of the degree of compression that can be achieved in a given soil. This study was aimed to compare different locations, (Guarapuava, Pinhão and Candói) at different depths (0-10, 10-20 and 20-40 cm for Guarapuava, 0-10, 10-25 and 25-40 cm for Pinhao and 0-15, 15-25 and 25-40 cm for Candói) as the maximum density of these soils. The samples were subjected to the normal Proctor test, determining the maximum density and the critical moisture for compaction. The accumulation of organic matter in the surface layer of soil provided a reduction of the maximum density and increased the critical moisture to soil compaction, increasing compression as there is an increase in depth.

Diferencia en la reacción a Pyricularia oryzae de materiales de trigo en los estadios vegetativo y reproductivo

RESUMEN La Piricularia o brusone causada por Magnaporthe oryzae B. C. Couch and L. M. Kohn (sin. Pyricularia oryzae), es actualmente considerada una de las más importantes enfermedades del trigo en Sudamérica, considerando las pocas fuentes de resistencia reportadas en el mundo, el objetivo del trabajo fue relacionar la resistencia a Pyricularia oryzae en hojas con la resistencia en espigas, en base a la inoculación de 61 materiales de trigo, pertenecientes al Programa Nacional de Trigo, del Instituto Paraguayo de Tecnología Agraria. Estos fueron seleccionados en base a su amplia variabilidad genética de progenitores para resistencia al patógeno. Las inoculaciones se realizaron en invernadero, cuando las plantas presentaban cuatro hojas para el estadio vegetativo y en espigazon para el estadío reproductivo, utilizando una suspensión de 2 105 conidios/mL de un aislado del hongo seleccionado por su alta virulencia en ensayos previos. De los 61 materiales evaluados, solo cuatro presentaron resistencia tanto en hoja como en espiga, y tres fueron resistentes a nivel foliar y moderadamente resistentes en espigas, demostrando la estrechez en la base de germoplasma resistente para las infecciones de brusone en las espigas. En base al bajo número de líneas consideradas resistentes a Pyricularia en este estudio, se enfatiza la necesidad de ampliar la resistencia genética en el germoplasma de trigo de manera urgente.

ABSTRACT The wheat blast caused by Magnaporthe oryzae B. C. Couch and L. M. Kohn (sin. Pyricularia oryzae), is currently considered one of the most important wheat disease in South America, considering the few sources of resistance reported in the world, the aim of this study was to relate Pyricularia oryzae resistance in leaves with the resistance in spikes, inoculating 61 wheat materials belonging to the National Wheat Program of the Instituto Paraguayo de Tecnología Agraria. These were selected based on their wide genetic variability. Inoculations were in greenhouse when the plants presented four leaves for the vegetative stage and in espogazon for the reproductive stage, using a suspension of 2.105 conidia/ ml from an isolate of fungus selected for its high virulence in previous trials. Of the 61 materials evaluated only four were resistant in leaf and in spikes, and three were resistant in leaf and moderately resistant in spikes, demonstrating the narrowness in the base of resistant germplasm for wheat blast infections in the spikes Based on the low number of lines considered resistant to Pyricularia in this study, the need to increase genetic resistance in wheat germplasm is urgently emphasized.