Historia y perspectivas del mejoramiento genético del maíz forrajero en la Argentina / History and prospects of fodder corn breeding in Argentina

RESUMEN El maíz se utiliza masivamente para producir alimentos para el hombre y los animales domésticos con granos de varias entidades taxonómicas o razas. Para los rumiantes domésticos también se utiliza la planta entera como forraje. En Argentina se utiliza el grano forrajero y el silaje de planta entera para el ganado vacuno de carne y leche. El objetivo de este trabajo fue desarrollar la historia y las perspectivas del maíz para grano y ensilaje, centrados en la selección y el mejoramiento genético. El maíz forrajero en sus dos variantes (grano forrajero y planta entera como silaje) tuvo distinta importancia a través del tiempo. Remarcamos la importancia del mejoramiento genético específico del maíz para silaje de planta entera para alcanzar un potencial de rendimiento y valor nutritivo superior a la de los híbridos graníferos. Se analizaron las cuatro estructuras genéticas poblacionales utilizadas en el tiempo como cultivares, que determinaron la evolución del proceso tecnológico de selección y mejoramiento genético. Con las investigaciones efectuadas, las empresas semilleras incorporaron nuestros protocolos a sus programas de desarrollo y de mejoramiento genético. La contribución de la selección y del mejoramiento genético en Argentina fue efectiva para transformar la planta de maíz en alimento para rumiantes y esto se incrementará con la obtención de híbridos específicos para silaje.

ABSTRACT Corn is used to massively produce food for humans and domestic animals with grains of various taxonomic entities or races. For domestic ruminants, the whole plant is also used as forage. In Argentina, both corn grain and whole-plant silage are used for beef and dairy cattle production. This paper aimed to develop the history and perspectives of corn grown for grain and silage, focusing on plant breeding. The importance of corn fodder in its two variants (grain and whole-plant silage) has varied over time. We emphasize herein the importance of the specific genetic breeding of corn used for whole-plant silage to achieve higher yield potential and nutritional value than grain hybrids. The four population genetic structures used over time as cultivars, which determined the evolution of the technological process of selection and breeding, were analyzed. Based on the research carried out, seed companies have incorporated our protocols into their development and breeding programs. The contribution of selection and breeding in Argentina was effective in transforming the corn plant into ruminant feed, and this will increase with the development of specific silage hybrids.

Effect of Snehadahana in the Management of Kadara - A Case Report

Kadara is a Kshudra Roga, first mentioned by Acharya Sushruta. It is a condition which causes extreme pain and discomfort to the affected person. Kadara may be correlated to Corn based on the causative factors, site of the swelling, clinical and other features. The incidence of corn in India is more than 10 million cases per year. The treatment modalities available at present in the modern science are the usage of corn caps, salicylic acid paints, cryotherapy and surgical excision. All theses modalities are associated with a high rate of recurrence. Snehadahana is mentioned as the line of management in Kadara after Utkarthana by all the Acharyas. Acharya Bhoja specifically mentions Tila Thaila as the Sneha dravya to be used for Agnikarma. In the present study, a 53 year old female patient, who visited the OPD of Sri Jayendra Saraswathi Ayurveda College and Hospital with a case of Kadara, was selected for Snehadahana. Chedana was done prior to Snehadahana. The procedure was carried out as 4 sittings, once a week, for a period of 4 weeks. Two follow ups were done at an interval of 14 days, after the fourth sitting of Snehadahana. There was complete healing of the wound and no recurrence seen until the follow up period.

Immobilization of Lactobacillus bulgaricus with gellan gum and its application in continuous fermentation of D-lactic acid from corn straw / 生物工程学报

Biorefinery of chemicals from straw is an effective approach to alleviate the environmental pollution caused by straw burning. In this paper, we prepared gellan gum immobilized Lactobacillus bulgaricus T15 gel beads (LA-GAGR-T15 gel beads), characterized their properties, and established a continuous cell recycle fermentation process for D-lactate (D-LA) production using the LA-GAGR-T15 gel beads. The fracture stress of LA-GAGR-T15 gel beads was (91.68±0.11) kPa, which was 125.12% higher than that of the calcium alginate immobilized T15 gel beads (calcium alginate-T15 gel beads). This indicated that the strength of LA-GAGR-T15 gel beads was stronger, and the strain was less likely to leak out. The average D-LA production was (72.90±2.79) g/L after fermentation for ten recycles (720 h) using LA-GAGR-T15 gel beads as the starting strain and glucose as the substrate, which was 33.85% higher than that of calcium alginate-T15 gel beads and 37.70% higher than that of free T15. Subsequently, glucose was replaced by enzymatically hydrolyzed corn straw and fermented for ten recycles (240 h) using LA-GAGR-T15 gel beads. The yield of D-LA reached (1.74±0.79) g/(L·h), which was much higher than that of using free bacteria. The wear rate of gel beads was less than 5% after ten recycles, which indicated that LA-GAGR is a good carrier for cell immobilization and can be widely used in industrial fermentation. This study provides basic data for the industrial production of D-LA using cell-recycled fermentation, and provides a new way for the biorefinery of D-LA from corn straw.

New bicompartmental model: an application for the production of gases using the in vitro technique / Novo modelo bicompartimental: uma aplicação para a produção de gases pela técnica in vitro

The purpose of this study was to propose a bicompartmental nonlinear model and to identify the best-performing model between the proposed model and the bicompartmental logistic (BL) mode regarding the quality of fit to the curve of cumulative gas production (CGP) using corn silage, sunflower, and their mixtures. Gas production was measured 2, 3, 4, 6, 8, 9, 10, 12, 15, 19, 24, 30, 36, 48, 72, and 96 h after beginning the in vitro fermentation process. The generated data were used to generate the parameters of each model tested using the stats package of the R computational tool version 4.0.4. The mathematical models were subjected to the following selection criteria: the adjusted coefficient of determination (Raj.), residual mean square (RMS), mean absolute deviation (MAD), and Akaike information criterion (AIC). It was demonstrated that the proposed model had better performance with a high Raj., and lower values of RMS, AIC, and MAD than the bicompartmental logistic model for the prediction of the parameters of cumulative gas production (CGP), per to present a superior fit in the set of criteria according to the methodology and conditions in which the present study was developed.(AU)

No presente trabalho, com silagem de milho, girassol e suas misturas, objetivou-se propor um modelo não linear bicompartimental e identificar entre o modelo proposto e Logístico Bicompartimental (LB), aquele que apresenta maior qualidade de ajuste à curva de cinética de produção cumulativa de gases (PCG). A leitura da produção de gás foi realizada nos tempos 2, 3, 4, 6, 8, 9, 10, 12, 15, 19, 24, 30, 36, 48, 72 e 96 horas, após o início do processo de fermentação in vitro. Os dados gerados foram utilizados para geração dos parâmetros de cada modelo testado com auxílio do pacote stats da ferramenta computacional R versão 4.0.4. Os modelos matemáticos foram submetidos aos seguintes critérios de seleção o coeficiente de determinação ajustado (Raj.), quadrado médio do resíduo (QMR), desvio médio absoluto (DMA) e o critério de informação de Akaike (AIC). Foi demonstrado que o modelo proposto teve melhor desempenho com altos Raj., e menores valores de QMR, AIC e DMA, por apresentar um ajustamento superior no conjunto dos critérios em comparação com o modelo logístico bicompartimental para a predição dos parâmetros de produção cumulativa de gases (PCG) de acordo com a metodologia e condições em que foi desenvolvido o presente estudo.(AU)

Determination of bongkrekic acid in corn flour by direct extraction ultra-high performance liquid chromatography tandem mass spectrometry / 公共卫生与预防医学

Objective To establish a direct extraction ultra-high performance liquid chromatography tandem mass spectrometry method for the determination of bongkrekic acid in corn flour. Methods Bongkrekic acid was directly extracted with 80% methanol from corn flour samples, and the supernatant after vortex and centrifugation was determined after passing through membrane filtration. At the same time, the corn flour samples were extracted by solid phase extraction. The determination results of the two methods were compared. Results The linearity of standard series was good within the range of2-20 μg/L, and the linearity coefficient was＞0.999. The determination result of the positive sample by direct extraction method was 193.40 mg/kg (n=6). Adding the standard to the blank sample at the levels of 2, 6, and 10 μg/L, the calculated recovery rate was 75.82% - 99.33%, and the relative standard deviation was 3.54 % - 8.45%. The detection limit of the method reached 6 μg/kg. After extraction by solid phase extraction, the determination result of the positive sample was 196.84 mg/kg (n=6). The recovery rate was 77.12% -100.83%, with a relative standard deviation of 8.32% - 9.54%. Conclusion Compared with the solid phase extraction, the direct extraction method for the extraction of bongkrekic acid from corn flour has the advantages of rapidity, simplicity, and cost savings.

Alternativas para el aprovechamiento del cuajilote (Parmentiera edulis): una especie agroindustrial subutilizada / Alternatives for the use of cuajilote (Parmentiera edulis): an underutilized agro-industrial species

Resumen El fruto de la especie Parmentiera edulis, conocida como cuajilote, se produce de forma abundante por temporada, es rico en nutrientes y puede ser aprovechado para elaborar alimentos. El objetivo de este trabajo fue establecer la viabilidad técnica de utilizar el cuajilote en la formulación de alimentos y bebidas fermentadas para promover su aprovechamiento comercial. Se determinó la composición nutricional, el contenido fenólico y su capacidad antioxidante. Los frutos se deshidrataron y se obtuvo una harina que se mezcló al 0 % (control), 5 %, 10 % y 15 % con harina de maíz, para preparar tortillas, y se evaluó su composición nutricional y aceptación organoléptica. También, se elaboró una bebida fermentada y una bebida destilada, usando Sacharomyces cereviseae, a partir de pulpa de fruta con y sin cáscara. Los mostos para la bebida fermentada se pasteurizaron a 72 ºC/15 s. El fruto presentó alto contenido de proteína (6.5 ± 2.5 %) y fibra (3.9 ± 1.6 %), de compuestos fenólicos y capacidad antioxidante. En las tortillas, al aumentar la cantidad de cuajilote se elevó la cantidad de fibra y proteína. Sensorialmente, las tortillas adicionadas con 5 % y 10 % de cuajilote fueron mejor aceptadas. En la bebida fermentada no se encontró diferencia significativa en sus parámetros fisicoquímicos al elaborarla con y sin cáscara, excepto para la acidez total. Tampoco modificó el rendimiento de producción de bebida fermentada o de alcohol destilado. El cuajilote es un fruto poco incorporado a la dieta que presenta propiedades funcionales nutricionales adecuadas y puede ser aprovechado como materia prima en la elaboración de tortillas, aumentando su valor nutricional o para producir bebidas fermentadas o alcohol etílico.

Abstract The fruit of the species Parmentiera edulis, known as cuajilote, is abundantly produced per season, is rich in nutrients and can be used to make food. The objective of this work was to establish the technical feasibility of using cuajilote in the formulation of fermented foods and beverages to promote its commercial use. The nutritional composition, the phenolic content and its antioxidant capacity were determined. The fruits were dehydrated and a flour was obtained that was mixed at 0 % (control), 5 %, 10 % and 15 % with corn flour, to prepare tortillas, and its nutritional composition and organoleptic acceptance were evaluated. Also, a fermented beverage and a distilled beverage were elaborated, using Saccharomyces cereviseae, from fruit pulp with and without shell. The musts for the fermented beverage were pasteurized at 72 ºC/15 s. The fruit presented a high content of protein (6.5 ± 2.5 %) and fiber (3.9 ± 1.6 %) of phenolic compounds and antioxidant capacity. In tortillas, increasing the amount of cuajilote increased the amount of fiber and protein. Sensorially, the tortillas added with 5 % and 10 % cuajilote were better accepted. In the fermented beverage, no significant difference was found in its physicochemical parameters when it was made with and without shell, except for total acidity. Nor did it modify the production yield of fermented beverage or distilled alcohol. Cuajilote is a fruit rarely incorporated into the diet that has adequate functional and nutritional properties and can be used as a raw material in the manufacture of tortillas, increasing its nutritional value or to produce fermented beverages or ethyl alcohol.

Digestibilidad aparente de materia seca, proteína y carbohidratos de la dieta con ensilado biológico de harina de maíz en Cryphiops (C.) caementarius / Apparent digestibility of dry matter, protein and carbohydrate of the diet with biological corn meal silage in Cryphiops (C.) caementarius

Resumen El objetivo del estudio fue determinar la digestibilidad aparente de la materia seca, proteína y carbohidratos de la dieta con ensilado biológico de harina de maíz en Cryphiops (C.) caementarius. Camarones adultos (4.50 a 7.20 cm de longitud total), se colectaron del río Pativilca (Lima, Perú) y en laboratorio se mantuvieron en recipientes individuales instalados dentro de seis acuarios (cuatro camarones por acuario). La dieta control fue sin ensilado y para la dieta experimental se reemplazó el 75% de la harina de maíz por el ensilado biológico de harina de maíz; ambas dietas tuvieron 1% de óxido crómico como marcador inerte. Los camarones fueron alimentados dos veces por día (40% a las 08:00 h y 60% a las 18:00 h) con el 6% del peso húmedo, durante 10 días. Para la colección de heces, los camarones fueron trasladados a un sistema de caja cribada (12 compartimentos) instalada dentro de un acuario. La digestibilidad aparente se determinó en base seca. Los camarones alimentados con la dieta con ensilado biológico de harina de maíz tuvieron altos coeficientes de digestibilidad aparente de carbohidratos (95.69%), proteína cruda (80.02%) y materia seca (76.19%), que aquellos alimentados con la dieta sin ensilado (p<0.05) que fue de 93.48, 78.21 y 74.36%, respectivamente. Los camarones adultos digieren con eficiencia los carbohidratos de la dieta con ensilado biológico de harina de maíz, en vez de la proteína de dicha dieta.

Abstract The aim of this study was to determine the apparent digestibility of dry matter, protein and carbohydrates of the diet with biological corn meal silage in Cryphiops (C.) caementarius. Adult prawn (4.50 to 7.20 cm total length) was collected from the Pativilca river (Lima, Peru) and in the laboratory each shrimp was kept in individual containers set up in six aquaria (four prawn per aquarium). The experimental diet was supplemented with corn meal biological silage and the control diet was without silage; both diets had 1% chromic oxide. Each diet had three replicates. Prawn was fed twice a day (40% at 08:00 h and 60% at 18:00 h) at 6% of wet weight for 10 days. For feces collection, the prawn was transferred to a system of sieved boxes (12 compartments) installed inside an aquarium. Apparent digestibility was determined on a dry basis. Prawn fed the diet with corn meal biological silage had higher apparent digestibility coefficient for carbohydrates (95.69%), crude protein (80.02%) and dry matter (76.19%) than those fed the diet without silage (p<0.05), which was 93.48, 78.21 and 74.36%, respectively. The adult prawn digested efficiently the carbohydrates of the corn meal biological silage diet, instead of the protein of this diet.

Colombian vs. American corn: Quality, chemical composition, mycotoxin content and metabolizable energy

Background: Corn is, quantitatively, one of the most important world crops (ranking second only after wheat) and a key ingredient in animal feeds. Objective: to assess and compare corn quality, mycotoxin content, chemical composition and apparent metabolizable energy (AME) of domestic and imported corn. Methods: Grain quality (USDA grading system) was determined in 30 samples of domestic and 21 samples of imported corn. From each origin, 15 samples were subjected to proximal analysis and 10 were used to determine fatty acid composition. Mycotoxin analysis was conducted on 30 samples of domestic and 23 of imported corn. Results: six of the 30 domestic samples corresponded to US1 grade (highest quality) vs. none of the imported. In the "sample grade" category (lowest quality), 10 and 6 samples corresponded to imported and domestic corn, respectively. Soybeans were found as contaminant in 15 of the 21 imported corn samples. Aspergillus spp. mycotoxins such as ochratoxin A were not detected, and aflatoxins were found in only a few samples at very low levels. Fusariotoxins such as deoxynivalenol and zearalenone were found in 61 and 43% of imported samples, respectively, but in none of the domestic samples. Domestic corn had lower carbohydrate content compared with imported corn (85.4 vs. 86.7%), but higher crude fat (3.8 vs. 3.1%). The AME values for domestic and imported corn were 3,697 and 3,378 kcal/kg, respectively. The fatty acid profiles from both corn types were similar. Conclusion: This study found significant differences between locally-grown and imported corn, particularly in terms of crude fat, AME content, fusariotoxins, and contaminant seeds (soybeans). These findings suggest that locally-grown corn might have nutritional and toxicological advantages over corn imported from the United States.

Antecedentes: El maíz es, cuantitativamente, uno de los cultivos más importantes a nivel mundial (ocupa el segundo lugar después del trigo) y uno de los principales ingredientes en dietas para animales. Objetivo: Evaluar y comparar la calidad del maíz, su contenido de micotoxinas, composición química, y energía metabolizable aparente (AME) del maíz nacional e importado. Métodos: La calidad del grano (sistema de clasificación de la USDA) se determinó en 30 muestras de maíz producido en Colombia y 21 de maíz importado. De cada origen, 15 muestras se sometieron a análisis proximal y 10 se analizaron para determinar el perfil de ácidos grasos. El contenido de micotoxinas se determinó en 30 muestras de maíz nacional y 23 de maíz importado. Resultados: Seis de las treinta muestras nacionales analizadas para calidad de grano correspondieron a grado US1 (la mejor calidad) frente a ninguna de las importadas. En categoría "grado muestra" (la menor calidad) se encontraron 10 y 6 de las muestras de maíz importado y nacional, respectivamente; 15 de las 21 muestras de maíz importado presentaron contaminación con semillas de fríjol soya. No se encontraron micotoxinas de hongos Aspergillus spp. (ocratoxina A), y niveles muy bajos de aflatoxinas en unas pocas muestras. Fusariotoxinas tales como deoxinivalenol y zearalenona se detectaron en el 61 y 43% de las muestras de maíz importado, respectivamente, pero en ninguna muestra de maíz nacional. El maíz nacional presentó menor contenido de carbohidratos (85,4 vs. 86,7%), pero mayor contenido de grasa cruda (3,8 vs. 3,1%) en comparación con el importado, respectivamente. Los valores de AME fueron de 3.697 y 3.378 kcal/kg para el maíz nacional e importado, respectivamente. El perfil de ácidos grasos de ambas procedencias fue similar. Conclusiones: Este estudio encontró diferencias significativas entre el maíz de producción nacional y el importado, en especial en su contenido de grasa cruda y AME, fusariotoxinas, y semillas contaminates (soya). Estos hallazgos sugieren que el maíz de producción nacional puede presentar ventajas de tipo nutricional y toxicológico frente al maíz importado de los Estados Unidos de América.

Antecedentes: O milho é quantitativamente uma das culturas mais importantes em nível mundial (ocupando o segundo lugar depois do trigo), sendo um dos principais ingredientes em dietas para animais. Objetivo: Avaliar e comparar a qualidade do milho, o teor de micotoxinas, a composição química e a energia metabolizável aparente (EMA) do milho nacional e importado. Métodos: A qualidade do grão (sistema de classificação do USDA) foi determinada em 30 amostras de milho produzido na Colômbia e 21 amostras de milho importado. Quinze amostras de cada tipo de milho foram submetidas a análise proximal e dez amostras de cada milho foram analisadas para determinar o perfil de ácidos graxos. O conteúdo de micotoxinas foi determinado em 30 amostras de milho da Colômbia e em 23 amostras de milho importado. Resultados: Seis das trinta amostras colombianas analisadas para qualidade de grão corresponderam a grau US1 (melhor qualidade) frente a nenhuma das amostras importadas. Na categoria "grau amostra" (menor qualidade) foram encontradas 10 e 6 amostras de milhos importados e colombianos, respectivamente; Quinze das 21 amostras de milho importado apresentaram contaminação com sementes de feijão soja. Não foram encontradas micotoxinas de fungos Aspergillus spp. (ocratoxina A) ou apenas níveis muito baixos em poucas amostras (aflatoxinas). As fusariotoxinas, deoxinivalenol e zearalenona foram detectadas em 61 e 43% das amostras de milho importado, respectivamente, mas não foram detectadas em nenhuma amostra do milho colombiano. O milho colombiano apresentou menor conteúdo de carboidratos (85,4 vs. 86,7%) porém maior conteúdo de gordura crua (3,8 vs. 3,1%). Os valores de AME foram 3.697 e 3.378 kcal/kg para as amostras de milho colombiano e importado, respectivamente. O perfil de ácidos graxos de ambos tipos de milho foi similar. Conclusões: Os resultados do presente estudo mostram diferenças significativas entre o milho de origem colombiana e o milho importado dos Estados Unidos, em especial no conteúdo de gordura crua e AME, fusariotoxinas e sementes contaminantes (soja). Estes achados sugerem que o milho de produção colombiana pode apresentar vantagens de tipo nutricional e toxicológica frente ao milho importado dos Estados Unidos.

Measurement of resource use efficiency in corn production: a two-stage data envelopment analysis approach in Turkey / Medição da eficiência do uso de recursos na produção de milho: uma abordagem de análise de dados em duas fases na Turquia

This research analyzed the efficiency situation of corn farms operating in the Adana province of Turkey. In this context, required farm management data were collected from 111 corn farmers by using face to face survey method during the 2019-2020 cultivation season. To determine the technical efficiency (TE) levels of corn farms, Data Envelopment Analysis (DEA) was applied. Furthermore, factors that cause the inefficiency in corn farms were detected by using the Tobit regression model. According to research results, the average TE levels of corn farms in the research area under the variable return to scale conditions are reported as 0.887 (111 farms). These results suggested that if farms reduced their input use by 11.3% on average, they can achieve the same output level and be able to reach full technical efficiency. The most ineffective source in terms of farms performance is machine expenditures with 68.2% of excessive use followed by labor use. In this regard, mechanization modernization, education and training of the labor force and more sensitive fertilizers and pesticide use can increase the efficiency of corn farms. Results of the Tobit regression model indicated that factors such as experience, education, number of tractors and size of the irrigated area positively influenced the TE, whereas family size in corn farming has a negative effect.

Esta pesquisa tem como objetivo analisar a situação de eficiência das fazendas de milho operando na província de Adana, na Turquia. Neste contexto, os dados necessários de gestão da fazenda foram coletados de 111 produtores de milho usando o método de pesquisa frente a frente durante a temporada de cultivo de 2019-2020. Para determinar os níveis de eficiência técnica (TE) das fazendas de milho, foi aplicada a Análise Envoltória de Dados (DEA). Além disso, os fatores que causam a ineficiência nas fazendas de milho foram detectados por meio do modelo de regressão Tobit. De acordo com os resultados da pesquisa, os níveis médios de TE das fazendas de milho na área de pesquisa sob as condições de retorno variável à escala são encontrados em 0,887 (111 fazendas). Esses resultados sugerem que, se as fazendas reduzirem o uso de insumos em 11,3% em média, podem atingir o mesmo nível de produção e alcançar eficiência técnica plena. A fonte mais ineficaz em termos de desempenho das fazendas são os gastos com máquinas, com 68,2% do uso excedente continuado com o uso de mão de obra. Nesse sentido, a mecanização, a modernização, a educação e o treinamento da força de trabalho e o uso de fertilizantes e pesticidas mais sensíveis podem ser sugeridos para aumentar a eficiência das fazendas de milho. Os resultados do modelo de regressão Tobit indicam que fatores como experiência, escolaridade, número de tratores e tamanho da área irrigada influenciaram positivamente no TE, enquanto o tamanho da família na cultura do milho tem efeito negativo.

Reaproveitamento de sabugo de milho para potencial remoção de formulação comercial de glifosato em fase aquosa pela técnica de adsorção / Corn cob reuse in the adsorption of a commercial formulation of glyphosate

RESUMO Neste estudo, foi produzido biocarvão de sabugo de milho ativado com ácido fosfórico (BCA) para potencial remoção do herbicida glifosato — GLF (formulação comercial) em meio aquoso. O BCA foi caracterizado por análises de difração de raios X, espectroscopia de infravermelho, adsorção e dessorção de N2, microscopia eletrônica de varredura e determinação do potencial de carga zero. O efeito do pH inicial e da massa de adsorvente também foi avaliado. Os resultados cinéticos de adsorção foram ajustados aos modelos de pseudoprimeira e pseudossegunda ordem. A natureza do processo foi estudada por meio dos modelos de isoterma de Langmuir e Freundlich, e os parâmetros termodinâmicos calculados para as temperaturas de 23, 43 e 63°C. Os resultados obtidos demonstraram que a adsorção de GLF no BCA foi dependente da temperatura, da massa de adsorvente e do pH do meio, com a melhor condição de ensaio caracterizada por 63°C, 0,25 g de BCA e pH = 7, resultando em boa eficiência de remoção (62,67%), porém com baixa capacidade de adsorção (2,67 mg.g−1). A cinética de adsorção foi representada pelo modelo de pseudossegunda ordem e considerada rápida, sendo necessários 15 min para atingir 98% da capacidade máxima de adsorção. Os dados da isoterma foram bem descritos pelo modelo de Freundlich. Por fim, o estudo termodinâmico revela que a adsorção de GLF é de natureza endotérmica (∆Hº > 0) e endergônica (∆Gº > 0). Os resultados apresentados confirmam que o BCA de sabugo de milho é um adsorvente capaz de remover GLF (formulação comercial) do meio aquoso.

ABSTRACT In this study a biochar was produced from corn cob (BCA), which was activated with phosphoric acid to verify its potential for removal of herbicide glyphosate (GLF) (commercial formula) in aqueous media. BCA was characterized by X-ray diffraction spectroscopy, infrared spectroscopy, sorption and desorption of N2, scanning electron microscope, and zero charge potential. Kinetic results of adsorption were adjusted to pseudo-first and pseudo-second order reactions. The adsorption process was studied to verify if it followed Freundlich and Langmuir isotherms, and the thermodynamic parameter was calculated for 23 oC, 43 cC and 63 oC. The results showed that adsorption of GLF on BCA depended on temperature, adsorbent mass, and pH. The best results were obtained for the temperature of 63 oC with 0.25 g de GLF and pH = 7.0, conditions that presented 62.3% of GLF removal and low adsorption capacity (2.67 mg. g−1). That was probably due to the porous nature of BCA and co-adsorption of other constituents that were present in the commercial formula of GLF. The adsorption kinetics was represented by the model of pseudo-second order and considered fast, taking 15 min to reach 98% of the maximum adsorption capacity. The isotherm data were well represented by the Freundlich model. Finally, the thermodynamic study demonstrated that the adsorption of GLF is of endothermic nature (ΔHº > 0) and endergonic (ΔGº > 0). The results confirmed that BCA from corn cob is an adsorbent capable of removing GLF (commercial formula) from aqueous media. However, the endothermic nature of the process can compromise its performance in water treatment processes.

Observation on the effect of 90Sr-90Y application combined with corn paste in the treatment of corns / 中国辐射卫生

Objective To evaluate the clinical efficacy and satety of 90Sr-90Y application combined with corn paste in the treatment of corns. Methods 85 patients with corns in the First People's Hospital of Tianmen from September 2019 to December 2020 were selected and randomly divided into group A, group B and group C based on random number table. In group A, 28 cases were treated with simple 90Sr-90Y application; in group B, 27 cases were treated with 90Sr-90Y application plus intermittent corns paste; in group C, 30 cases were treated with 90Sr-90Y application plus continuous corns paste.The treatment effect, recovery time, recurrence rate and incidence of adverse reactions of the three groups were compared. Results The cure rates of the three groups were 78.57% (21/28), 81.48% (22/27) and 83.33% (25/30), with no significant difference (P > 0.05); the total effective rates were 92.86% (26/28), 92.59% (25/27) and 96.67% (29/30), the difference was not significant (P > 0.05); the cure time was (5.67 ± 1.80) weeks, (2.82 ± 1.11) weeks and (2.24 ± 1.05) weeks, the cure time of the B and C groups was significantly shorter than that of the A group (P < 0.05); The incidence of adverse reactions were 9.52% (2/21), 4.55% (1/22) and 4.00% (1/25), respectively, the difference was not significant (P > 0.05); the incidence of adverse reactions were 3.57% (1/28), 11.11% (3/27) and 26.67% (8/30), the incidence of adverse reactions in group C was higher than Group A (P < 0.05). Conclusion The combination of 90Sr-90Y application and intermittent corns paste in the treatment of corns has good curative effect, low recurrence rate, short cure time and few adverse reactions. It is worthy of clinical promotion.

Characterization of plantaricin IIA-1A5 biosynthesized by Lactobacillus plantarum IIA-1A5 in corn steep liquor based medium

Aims@#To characterize the plantaricin IIA-1A5 crude extract that biosynthesized by Lactobacillus plantarum IIA-1A5 using corn steep liquor (CSL) based medium. @*Methodology and results@#Lactobacillus plantarum IIA-1A5 was grown in several media containing different components including corn steep liquor (CSL), molasses and MRS (de Man Rogosa Sharpe) as control medium for 24 h at 37 °C. Antibacterial activities of the cell-free supernatant were expressed as diameter of inhibition zones observed by paper disc method. The results showed that CSL medium produced cell-free supernatant of L. plantarum IIA-1A5 with significantly higher antibacterial activity againts Staphylococcus aureus ATCC 25923 (9.81 mm), Lactobacillus monocytogenes ATCC 7644 (9.61 mm), Bacillus cereus (8.97 mm) and Escherichia coli ATCC 25922 (9.23 mm) were not significantly different compared to control MRS broth media (9.59 mm). CSL medium added only with 3% yeast extract and Tween 80 produced supernatant which showed similar antibacterial activity either to 10% molasses or control medium (Medium K and B). The CSL medium was considered more efficient and low cost, therefore this medium was selected for production and characterization of plantaricin IIA-1A5 crude extract. Further characterization performed by SDS PAGE analysis showed that crude plantaricin had molecular weight of approximately 9.9 kDa, higher than that produced in control medium (8.0 kDa). However, both plantaricins were categorized under the same class for small bacteriocin (class II). This study also revealed the plantaricin IIA-1A5 produced in CSL medium was stable to heat and pH and not significantly different compared to control MRS broth media. The antibacterial activity of plantaricin IIA-1A5 crude extract against S. aureus ATCC 25923 (10.09 mm) was not significantly different with 1000 ppm sodium benzoate (9.70 mm) and 300 ppm sodium nitrite (9.82 mm).@*Conclusion, significance and impact of study@#The CSL medium produced cell-free supernatant of L. plantarum IIA 1A5 had significant antibacterial activity characterization againts S. aureus ATCC 25923, L. monocytogenes ATCC 7644, B. cereus and E. coli ATCC 25922. Comparison of the inhibition activity of plantaricin IIA-1A5 crude extract against pathogen with synthetic preservatives indicated that plantaricin IIA-1A5 crude extract have the potency to replace synthetic preservatives. CSL based medium is potential to be used for low-cost plantaricin IIA-1A5 production.

Residues of glyphosate and aminomethylphosphonic acid (AMPA) in genetically modified glyphosate tolerant soybean, corn and cotton crops / Resíduos de glifosato eácido aminometilfosfônico (AMPA) em culturas de soja, milho e algodão geneticamente modificados tolerantes ao glifosato

ABSTRACT: Glyphosate is a broad-spectrum herbicide capable of controlling a wide range of weed. It uses could cause the occurrence of residues in conventional or genetically modified crops. For this purpose, grains (soybean and corn) and cotton seeds were sampled from commercial areas in 2012/2013 to 2017/2018 seasons in different Brazilian agricultural regions to monitor glyphosate residues levels and its metabolite (aminomethylphosphonic acid - AMPA) after different managements. The glyphosate residues levels ​​in genetically modified corn (GM) ranged from no detected (ND) to 0.15 mg kg-1, in GM soybean values ​​ranged from ND to 2.81 mg kg-1 and in GM cotton ranged from ND to 1.78 mg kg-1. AMPA residues levels ​​indicated a correlation with the glyphosate residues. Glyphosate residues levels in soybean and corn grains and cotton seeds were within the Maximum Residue Limits (MRLs) established by ANVISA and Codex Alimentarius.

RESUMO: O glifosato é um herbicida de amplo espectro capaz de controlar uma grande diversidade de ervas daninhas e seu uso pode acarretar na ocorrência de resíduos, seja em culturas convencionais ou geneticamente modificadas. Sendo assim, amostragens de grãos de soja e milho e de sementes de algodão foram realizadas em áreas comerciais nas safras de 2012/2013 a 2017/2018 em diferentes regiões agrícolas brasileiras com o objetivo de monitorar os níveis de resíduos de glifosato e seu metabólito (ácido aminometilfosfônico - AMPA) após diferentes manejos. Os níveis de resíduos de glifosato em milho geneticamente modificados (GM) tolerante ao glifosato variaram desde não detectados (ND) a até 0,15 mg kg-1, em soja GM tolerante ao glifosato os valores variaram de ND a 2,81 mg kg-1 e em algodão GM tolerante ao glifosato os resultados se estabeleceram entre ND a 1,78 mg kg-1. Os valores de resíduos de AMPA indicaram correlação com os resíduos de glifosato. Os níveis de resíduos de glifosato em grãos de soja e milho e sementes de algodão ficaram dentro dos Limites Máximos de Resíduos (LMRs) preconizados pela ANVISA e Codex Alimentarius.

Apparent nutrient digestibility of carbohydrate (corn) in Cirrhinus mrigala under the influence of chromium chloride hexahydrate / Digestibilidade aparente de nutrientes oriundos de carboidratos (milho) em Cirrhinus mrigala sob a influência do cloreto de cromo hexa-hidratado

Abstract A feeding trial was carried out to assess the effect of dietary chromium supplementation on apparent nutrient digestibility coefficient (%) of gelatinized and non-gelatinized corn in Cirrhinus mrigala fingerlings for 90 days. Using various levels of chromium chloride hexahydrate six test diets designated as T1 (G/0.0 Cr2Cl3.6H2O mg Kg-1), T2 (NG/0.0 Cr2Cl3.6H2O mg Kg-1), T3 (G/0.2 Cr2Cl3.6H2O mg Kg-1), T4 (NG/0.2 Cr2Cl3.6H2O mg Kg-1), T5 (G/0.4 Cr2Cl3.6H2O mg Kg-1) and T6 (NG/0.4 Cr2Cl3.6H2O mg Kg-1) were prepared. Results showed highest apparent digestibility coefficient (ADC) of nutrients dry matter, crude lipid and gross energy in test diet T5 that was gelatinized and supplemented with chromium 0.4 mg/Kg while, for crude protein higher value of nutrient digestibility was recorded in T3 test diet (G/0.2 Cr2Cl3.6H2O mg/Kg). It was concluded that chromium supplementation with gelatinized corn in fish (Cirrhinus mrigala) diet can improve the nutrients digestibility more efficiently.

Resumo Um experimento referente à alimentação foi realizado para avaliar o efeito da suplementação dietética de cromo, no coeficiente de digestibilidade aparente do nutriente (%) do milho gelatinizado e não gelatinizado em alevinos de Cirrhinus mrigala por 90 dias. Usando vários níveis de cloreto de cromo hexa-hidratado, seis dietas testes foram designadas e preparadas como: T1 (G/0,0 Cr2Cl3.6H2O mg Kg-1); T2 (NG/0,0 Cr2Cl3.6H2O mg Kg-1); T3 (G/0,2 Cr2Cl3.6H2O mg Kg-1); T4 (NG/0,2 Cr2Cl3.6H2O mg Kg-1); T5 (G/0,4 Cr2Cl3.6H2O mg Kg-1) e T6 (NG/0,4 Cr2Cl3.6H2O mg Kg-1). Os resultados mostraram maior coeficiente de digestibilidade aparente (CDA) em matéria seca de nutrientes, lipídios brutos e energia bruta na dieta teste T5, que foi gelatinizada e suplementada com cromo 0,4 mg / Kg; enquanto que para a proteína bruta, foi registrada maior digestibilidade dos nutrientes na dieta teste T3 (G/0,2 Cr2Cl3.6H2O mg/Kg). Concluiu-se que a suplementação de cromo com milho gelatinizado na dieta de peixes (Cirrhinus mrigala) pôde melhorar a digestibilidade dos nutrientes de forma mais eficiente.

Phytochemical analysis of baby corn silk extracts

BackgroundBaby corn silk extract can be used as an antioxidant dietary supplement. However, insufficient data exists for this extract to guarantee its quality, efficacy and safety.ObjectiveTo determine phytochemical constituents, contents of phenolics and flavonoids, antioxidant activities, heavy metal concentrations, and microbial contamination of baby corn silk extracts.Material and methodsBaby corn silks including Pacific 271 and Zeba SG 17 hybrids were individually extracted with 40% v/v ethanol and distilled water to obtain Pacific 271 ethanol extract (PE), Zeba SG 17 ethanol extract (ZE), Pacific 271 aqueous extract (PA), and Zeba SG 17 aqueous extract (ZA). The analysis of phytochemical constituents was carried out using phytochemical tests, TLC screening, UV-visible, FTIR, and 1H NMR experiments. The contents of phenolics and flavonoids were determined using the modified Folin-Ciocalteu and aluminium chloride colorimetric procedures, respectively. Antioxidant activities were investigated using DPPH and FRAP assays. The concentrations of heavy metals were analyzed by ICP-MS. Microbial enumeration tests were carried out according to the United States Pharmacopeia (USP) 41.ResultsPE and ZE were composed of flavonoids, tannins, terpenoids, and steroids while PA and ZA contained flavonoids and tannins. PE and ZE exhibited higher total phenolic and flavonoid contents and significantly stronger antioxidant activities than PA and ZA. All extracts conformed to the microbiological and heavy metal requirements according to Association of South East Asian Nations (ASEAN) guidelines.ConclusionPE and ZE were considered appropriate to use as natural extracts of phenolics and flavonoids with antioxidant activities and safety.

Evaluation of methodologies of urine collection to estimate microbial synthesis in bovines diets containing lipids or not / Avaliação de metodologias de coleta de urina para estimar a síntese microbiana em dietas de bovinos contendo ou não lipídios

This study investigated the effectiveness of the urine sample collection method in predicting the volume urinary and synthesis of microbial nitrogen. Eight fistulated steers were used with accessible rumens and kept in individual stalls. Their diets consisted of corn silage; corn silage + concentrate; corn silage + concentrate with addition of lipids in the form of soybean oil; and corn silage + concentrate with addition of lipids in the form of soybean grains. Estimates of microbial protein synthesis were obtained based on the urinary excretion of purine derivatives. There was no effect of diets on daily creatinine excretion (P>0.05). There were differences (P<0.05) between the urinary volume and microbial synthesis values determined by the total urine collection and those estimated from the urine spot samples and equations proposed by different authors. The estimation of microbial synthesis based on the urine excretion of purine derivatives should be performed from the total collection of the urine for a period of 24 hours.

Este estudo investigou a eficácia do método de coleta de amostras de urina sobre a predição do volume urinário e síntese de nitrogênio microbiano. Oito novilhos fistulados foram utilizados com rúmen acessível e mantidos em baias individuais. Suas dietas consistiram de silagem de milho; silagem de milho + concentrado; silagem de milho + concentrado com adição de lipídios na forma de óleo de soja; e silagem de milho + concentrado com adição de lipídios na forma de grãos de soja. Estimativas de síntese de proteína microbiana foram obtidas com base na excreção urinária de derivados de purina. Não houve efeito de dietas na excreção diária de creatinina (P> 0,05). Houve diferenças (P <0,05) entre o volume urinário e os valores de síntese microbiana determinados pela coleta total de urina e os estimados a partir das amostras de manchas de urina e equações propostas por diferentes autores. A estimativa da síntese microbiana baseada na excreção de urina dos derivados de purina deve ser realizada a partir da coleta total da urina por um período de 24 horas.

Intake, nitrogen balance and microbial protein synthesis of steers fed with or without lipid addition / Consumo, balanço de nitrogênio e síntese de proteína microbiana de novilhos alimentados com ou sem adição de lipídios

This study investigated the influence of energy supplementation with or without the addition of lipids on microbial production, microbial synthesis efficiency and nitrogen balance. Eight fistulated steers were used with accessible rumens and kept in individual stalls. Their diets consisted of corn silage; corn silage + concentrate; corn silage + concentrate with addition of lipids in the form of soybean oil; and corn silage + concentrate with addition of lipids in the form of soybean grains. Estimates of microbial protein synthesis were obtained based on the urinary excretion of purine derivatives. The concentrations of ammonia in the rumen were determined immediately at 2, 4, 6 and 8 hours after feeding. The diets with concentrate increased (P<0.05) the microbial protein synthesis and the efficiency of the synthesis and nitrogen balance without a difference between the lipid sources (P>0.05). Concentrated diets presented higher concentrations of urea nitrogen in the serum and urinary urea excretion (P<0.05), but there was no difference between the lipid sources (P>0.05). Energy supplementation, with or without lipid addition, can be used as a strategy to increase the synthesis of the microbial protein in the cattle fed corn silage.

Este estudo investigou a influência da suplementação energética com ou sem adição de lipídios na produção microbiana, eficiência de síntese microbiana e balanço de nitrogênio. Oito novilhos fistulados foram utilizados com rúmen acessível e mantidos em baias individuais. Suas dietas consistiram de silagem de milho; silagem de milho + concentrado; silagem de milho + concentrado com adição de lipídios na forma de óleo de soja; e silagem de milho + concentrado com adição de lipídios na forma de grãos de soja. Estimativas de síntese de proteína microbiana foram obtidas com base na excreção urinária de derivados de purina. As concentrações de amônia no rúmen foram determinadas imediatamente às 2, 4, 6 e 8 horas após a alimentação. As dietas com concentrado aumentaram (P<0,05) a síntese de proteína microbiana e a eficiência da síntese e o balanço de nitrogênio sem diferença entre as fontes lipídicas (P>0,05). As dietas concentradas apresentaram maiores concentrações de nitrogênio uréico no soro e excreção urinária de uréia (P <0,05), mas não houve diferença entre as fontes lipídicas (P>0,05). A suplementação energética, com ou sem adição de lipídios, pode ser utilizada como estratégia para aumentar a síntese da proteína microbiana em bovinos alimentados com silagem de milho.

Beef quality of Nellore steers fed dried or rehydrated and ensiled corn or sorghum grains / Calidad de la carne de Ganado Nelore alimentado con grano de maíz o sorgo seco o rehidratado y ensilado / Qualidade de carne de bovinos Nelore alimentados com grãos de milho ou sorgo seco ou reidratado e ensilado

Abstract Background: Rehydration of grains, such as corn and sorghum, is used to increase nutrient absorption. However, the effect of this practice on meat quality is poorly understood. Objective: To evaluate the effects of type of grain and processing on the meat quality of Nellore steers in a feedlot. Methods: Twenty-four non-castrated Nellore steers (270 ± 53 kg initial body weight) were distributed in a completely randomized 2×2 factorial design, with six replicates. The first factor was cereal type (corn or sorghum), and the second was the grain processing (dry or rehydrated and ensiled). The diets were composed of 30% corn silage and 70% concentrate. Sixty days before the beginning of the experiment, corn and sorghum grains were rehydrated and ensiled. The animals were slaughtered after 140 days of confinement. Meat quality analyses were determined in samples of fresh and aged meat (7 days) from the Longissimus lumborum muscle. Results: no difference between treatments was observed for carcass pH and L* (lightness), a* (redness), and b* (yellowness) values, shear force, thawing and cooking losses, and chemical composition of meat (p>0.05). The b* (yellowness) value of subcutaneous fat was higher in steers fed corn, regardless of grain processing (p=0.03). Sarcomere length was higher in aged meat of steers fed sorghum, regardless of processing method (p=0.01). Conclusions: the grain processing method does not affect beef quality; however, grain type can affect subcutaneous fat color and sarcomere length of aged beef.

Resumen Antecedentes: La rehidratación de granos, tales como maíz y sorgo, se usa para aprovechar mejor sus nutrientes. Sin embargo, es poco conocido el efecto de esta práctica sobre la calidad de la carne. Objetivo: Evaluar los efectos del tipo de cereal y su procesamiento sobre la calidad de carne de toretes Nelore en confinamiento. Métodos: Veinticuatro novillos Nelore enteros con un peso promedio inicial de 270 ± 53 kg, se distribuyeron en un diseño factorial 2×2 completamente aleatorizado (n=6). El primer factor fue el tipo de cereal (maíz o sorgo) y el segundo fue su procesamiento (seco o rehidratado y ensilado). Las dietas estuvieron compuestas por 28,44% de ensilaje de maíz y 71,56% de concentrado. Sesenta días antes de iniciar el experimento, los granos de maíz y sorgo se rehidrataron y ensilaron. Los animales se sacrificaron después de 140 días de confinamiento. La calidad de la carne se determinó en muestras de carne fresca y madurada (7 días) obtenidas del músculo Longissimus lumborum. Resultados: No hubo diferencias entre tratamientos para el pH de las canales, ni para los valores de color (L* "luminosidad", a* "intensidad de rojo" y b* "intensidad de amarillo"), fuerza de corte, composición química, o pérdidas de agua por descongelamiento o cocción (p>0,05). El valor de b* de la grasa subcutánea fue mayor en los novillos alimentados con maíz, independientemente del tipo de procesamiento (p=0,03). La longitud de sarcómero fue más alto en la carne madurada de novillos alimentados con sorgo, sin importar el método de procesamiento (p=0,01). Conclusiones: El método de procesamiento del grano no afecta la calidad de la carne; sin embargo, el tipo de cereal afecta el color de la grasa subcutánea y la longitud del sarcómero de la carne madurada.

Resumo Antecedentes: A reidratação de grãos, como milho e sorgo, tem sido usada para aumentar a utilização de seus nutrientes. Contudo, o efeito dessa prática na qualidade da carne é pouco compreendido. Objetivo: Avaliar os efeitos do tipo de grão de cereais e seu processamento sobre a qualidade da carne de bovinos confinados. Métodos: Vinte e quatro bovinos Nelore não castrados, com peso corporal médio inicial de 270 ± 53 kg foram distribuídos em delineamento inteiramente casualizado, fatorial 2×2, com seis repetições. O primeiro fator foi o tipo de grão de cereal no concentrado (milho ou sorgo), e o segundo foi o processamento destes grãos (seco ou reidratado e ensilado). As dietas foram compostas por 28,44% de silagem de milho e 71,56% de concentrado. Sessenta dias antes do início do experimento, os grãos de milho e sorgo foram reidratados e ensilados. Os animais foram abatidos após 140 dias de confinamento. As análises de qualidade da carne foram determinadas em amostras não maturadas e maturadas (7 dias) obtidas do músculo Longissimus lumborum. Resultados: Não houve diferenças significativas (p>0,05) entre os tratamentos para pH da carcaça e L* (luminosidade), a* (intensidade de vermelho), b* (intensidade de amarelo), força de cisalhamento, perdas por descongelamento, perdas por cocção, perdas totais e composição química da carne. O valor de b* da gordura subcutânea foi maior (p=0,03) em bovinos alimentados com dietas contendo grãos de milho, independentemente do tipo de processamento. O comprimento de sarcômero foi maior na carne maturada de novilhos alimentados com sorgo, independente do método de processamento (p=0,01). Conclusões: O método de processamento dos grãos não afetou a qualidade da carne bovina, no entanto, a cor da gordura subcutânea e o comprimento de sarcômero da carne maturada foram afetados pelo tipo de grão.

Identification of various Candida species isolated from patients with vulvovaginal candidiasis attending a tertiary care hospital in North India

Background: Vulvovaginal Candidiasis (VVC) is a condition diagnosed in a large proportion of women presenting with complaints of abnormal vaginal discharge. The risk of VVC is high in women with diabetes mellitus, pregnancy, using oral contraceptives or broad-spectrum antibiotics and those having Human Immunodeficiency Virus infection.Objective of the present study was to identify the various species of Candida isolated from patients with Vulvovaginal Candidiasis.Methods: A cross-sectional study was done from January to June 2018. A total of 69 clinically suspected VVC cases were included in the study whose high vaginal swabs were collected and subjected to direct microscopy and cultured on Sabouraud Dextrose Agar (SDA). Creamy white pigmented colonies on SDA were confirmed as Candida by doing Gram抯 staining. Speciation of positive cultures was confirmed by conventional methods like Corn Meal agar culture, Germ tube test (GTT), Candida CHROM Agar Medium (CAM), sugar assimilation and fermentation test.Results: Out of 69 clinically suspected VVC cases included in the study, only 14 cultures were positive for Candida species. All the 14 isolates were found to be Non-albicans Candida (NAC). Most common species isolated were Candida glabrata 7(50%), followed by Candida tropicalis 3(21.4%), Candida lusitaniae 3(21.4%), and Candida parapsilosis 1 (7.1%).Conclusions: Candida albicans was known to be the most common causative agent of VVC as it was isolated in 90% cases. However, this study showed that all isolates from VVC were Non-albicans Candida. Therefore, species identification should be done in all microbiology laboratories for accurate diagnosis of VVC.

Trichogramma pretiosum in field release and under different temperatures in laboratory / Trichogramma pretiosum em liberação no campo e sob diferentes temperaturas em laboratório

This study aimed to evaluate a strain of Trichogramma pretiosum native to the central region of the state Rio Grande do Sul, Brazil, under different temperatures in laboratory and the parasitism of Helicoverpa zea after releases in corn field. Trichogramma pretiosum females were kept at 18, 25 and 30 °C and had their parasitism potential evaluated. Nine plots (400 m2) of maize were installed in randomized blocks under the treatments: 1) staggered release of parasitoids in three different occasions, at three-day intervals; 2) a single release of parasitoids; 3) no release of parasitoids. Ears were collected every four days and the number of caterpillars and eggs of H. zea in the maize silk and the number of damaged ears were estimated. Evaluation started after the tassels growth and ended with the drying of the styles-stigmas. To estimate the grain mass and the ear number and mass, two lines in each plot were delimited and reserved at the end of the cultivation cycle. In laboratory, the highest parasitism rate occurred at 25 °C (35.54%) and the lowest longevity at 30 °C (6.8 days). A total of 1,063 H. zea eggs were collected in the field, 69.52% were parasitized. The mean parasitism rate was higher in T1 (staggered release, 82.77%) than in control (51.87%), but there was no difference in grain yield. Based on the parasitism capacity of the studied strain, it can be potentially used in programs of biological control of H. zea in corn crops of Rio Grande do Sul.(AU)

O estudo objetivou avaliar uma linhagem de Trichogramma pretiosum nativa da região Central do Rio Grande do Sul (Brasil) sob diferentes temperaturas em laboratório, e no parasitismo de Helicoverpa zea após liberações em área de milho. Fêmeas de T. pretiosum foram mantidas a 18, 25 e 30 °C e avaliadas quanto ao potencial de parasitismo. No campo, foram instaladas nove parcelas (400 m2) de milho híbrido em blocos ao acaso, com os seguintes tratamentos: 1) liberação de parasitoides fracionada em três vezes, em intervalos de três dias; 2) liberação em apenas uma ocasião; 3) sem liberação. A cada quatro dias foram coletadas espigas e registrados os danos e o número de lagartas e ovos de H. zea dos estilos-estigmas. A avaliação iniciou durante o pendoamento e estendeu-se até a fase de secagem dos estilos-estigma. Duas linhas em cada parcela foram reservadas para avaliação do número e da massa de espigas e grãos. Em laboratório, o maior percentual de parasitismo foi aos 25 °C (35,54%) e a menor longevidade aos 30 °C (6,8 dias). No campo, foram coletados 1.063 ovos de H. zea, dos quais 69,52% estavam parasitados. O percentual médio de parasitismo foi maior com liberação escalonada de T. pretiosum (82,77%), comparativamente ao controle (51,87%), porém, não houve diferença na produção de grãos. Tendo em vista a capacidade de parasitismo da linhagem avaliada, sugere-se que ela possui potencial para ser utilizada em programas de controle biológico da lagarta da espiga no cultivo de milho no Rio Grande do Sul.(AU)