Desenvolvimento do capim-marandu com altura fixa ou variável durante as estações do ano

Aimed to identify, for assessing the tillering dynamics and morphogenesis , strategy (s ) suitable ( s) defoliation management to optimize the appearance of tillers and biomass of Urochloa Brizantha syn. Brachiaria brizantha cv. Marandu ( marandugrass ) throughout the year. The experiment was conducted from January 2013 to May 2014 were studied three strategies defoliation: Marandugrass with 30 cm throughout the experimental period (constant height); Marandugrass 15 cm in winter, the spring 30 cm and 45 cm in summer (increasing height); and Marandugrass 45 cm in winter, the spring 30 cm and 15 cm in summer (descending height). The experimental design was completely randomized in a split plot in time, with four replications. In winter, in the spring and summer, the following variables were calculated: appearance rate (TApP), mortality (TMoP) and survival (TSoP) of tillers, balance (BAL) between TApP and TMoP, stability index (IE) numbers of tillers and leaf elongation rates and stem, length of leaf blade and stem, leaf senescence rate, phyllochron and duration of life of the sheet. The TAPP was higher in the early spring and summer. For TMoP, the highest values were in the late spring and summer. The balance between TApP and TMoP was negative in winter and late spring, regardless of defoliation strategy. There was no difference in IE between the heights of the canopy during winter and late spring .. The number of tillers was higher in early spring and summer and lower in winter and late spring. The defoliation strategies have not changed phyllochron, leaf elongation rate. In spring and summer, there were increases in the rates of appearance, elongation and leaf senescence and, furthermore, decreased life span and phyllochron sheet. The plant height with increasing showed a lower rate of senescence and lower culm length in the spring. To increase the number of tillers marandu, it is advantageous to handle the plant with increasing height, ie, 15 cm in autumn and winter, the spring 30 cm and 45 cm in summer.The maintaining of B. brizantha cv. Marandu with fixed height of 30 cm or with variations between 15 and 45cm from the fall/winter to summer, does not influence the appearance and the growth of leaves per tiller, which indicates great flexibility on management defoliation in this forage plant.

Estrutura e dinâmica de perfilhamento do capim-marandu com alturas variáveis no inverno

The livestock system in Brazil mainly uses the pastures as source of food to cattle, and the marandu palisade grass is one of the main forage crop plants. In order to supply the demand of these animals in amount of forage, it is necessary to adopt management strategies aimed at increased forage production with adequate characteristics to animal intake. In this context, is requiered to identify management strategies of defoliation that improve tillering of marandu palisade grass during the seasons. There is a chance that the maintenance of lower marandu palisade grass during the fall and winter compared to spring and summer, increase the incidence of light at the base of the plants and, indeed, encourage tillering and modify the structure of the pasture compared to maintain marandu palisade grass with constant height along these stations.

Método para la obtención de cultivares de tomate con frutos partenocárpicos (sin semillas) y mayor calidad organoléptica

El método se basa en la transferencia y expresión del gen LFY de Arabidopsis thaliana en plantas transgénicas de tomate. Los frutos de las plantas transgénicas con el gen LFY mantienen el mismo tamaño y peso que los del cultivar original, pero carecen de semillas, tienen más carne, menos pulpa y una forma ligeramente apuntillada. El análisis de calidad refleja un incremento del 60 % en el contenido en sólidos solubles (la media alcanza 6,12 ºBrix) y del 60 % en ácidos valorables (la media llega al 0,72 %), lo que indica una mejora de la calidad organoléptica de los frutos en comparación con los del cultivar original no transgénico. Además, los frutos de las plantas transgénicas tienen otros atributos que indican una mayor calidad, tales como un mayor contenido en azúcares (sobre todo glucosa y fructosa) y licopeno, una sustancia que tiene propiedades antioxidantes.

Comportamiento agronómico y adaptabilidad de cuatro cultivares de maíz (Zea mays L.) en nueve localidades de los municipios de Darío, San Ramón y San Dionisio, departamento de Matagalpa, postrera 2013

El presente trabajo se realizó en nueve localidades de los municipios de Ciudad Darío, San Ramón y San Dioni sio, departamento de Matagalpa en la época de postrera 2013 . Con el objetivo de evaluar y determinar la adaptabilidad de dos cultivares de maíz locales ( Tuza Morada y Olote Rojo) y dos cultivares mejorados (H - INTA 991 y H - 5). La decisión de los materiales a estudiar estuvo totalmente a cargo de los propios productores en cada comunidad y finca. El diseño en campo consistió en una sola repetición por variedad en cada una de las 16 finca s con dimensiones de 4.50 m de ancho por 10 m de largo para un área total de 45.0 m 2 . La parcela útil fue los 4 surcos centrales de 3.0 m de ancho por 5.0 m de largo para una superficie de 15.0 m 2 . La siembra se realizó al espeque depositando dos semillas por golpe. Para la evaluación se analizaron 14 variables cuantitativ a s mediante estadística descriptiva (medias, varianza , desviación estándar, coeficiente de variación, valores máximos y mínimos). El análisis de adaptabilidad se hizo por medio de regresión lineal . Entre los resultados se destaca que los c ultivares est udiados demostraron una gran variabilidad fenotípica al presentar coeficientes de variación alto (mayor de 20 ), s iendo el cultivar H - 5 el q ue obtuvo la menor variabilidad fenotípica. Aunque no fue posible tener todos los cultivares en las localidades y finca dentro de las localidades cada uno mostro resultado de variabilidad fenotípica en mayor a menor por los altos coeficientes de variación obtenidos que reflejan variabilidad fenotíp ica. Los cultivares locales se destacaron , sobresaliendo el cultivar Olote Rojo el que según el análisis de regresión lineal resultó como el más estable y , el cultivar Tuza Morada con un rendimiento promedio de 2295.5 kg ha - 1 fue el que resultó ser el más adaptable y el que logró el mayor potencial de rendimiento. E l cultivar mejorado H - INTA 991 (con un rendimiento promedio de 1581.16 kg ha - 1 ) respondió muy bien ocupando el segundo lugar en cuanto al potenci al de rendimiento y adaptabilidad.

Adaptação de cultivares diploides e tetraploides de azevém anual às condições climáticas do sudoeste do Paraná

Annual ryegrass is one of the species that best meets the needs of ranchers of southern Brazil during the winter period of the year. The breeding of ryegrass for many years has been developing superior materials, diploid and tetraploid, which, despite its higher prices for seed are being used by producers because of their better performance and quality. The objective of this research was to evaluate the behavior of different cultivars of Italian ryegrass - diploid and tetraploid, grazing, climate conditions of southwestern Paraná. The experiment was conducted in the city of Pato Branco / PR. The experimental design was a randomized block design with four replications. The observed cultivars were: LE 284, Camaro, Bakarat, Estações, Ponteio and Nibbio (diploid) and Winter Star, KLM 138, Escorpio, Titan, Barjumbo and Potro (tetraploid). The grazing was mob-grazing type time respecting input of 25 cm and 10 cm high output. It was observed that the cultivars that had high period of pasture use were those that produced larger amounts of forage. For all cultivars the highest forage accumulations occur between the months of August, September and October. Tetraploid have lower population density of tillers, but this does not affect the IAF among cultivars nor the interception of solar radiation before and after the completion of a grazing. NDF and ADF contents linearly increase with advancing in ryegrass cultivars development cycle. On average, tetraploid cultivars produce larger amounts of forage in relation to diploid cultivars.

Caracterização fisio-molecular de cultivares de feijão (Phaseolus vulgaris L.) em resposta à deficiência hídrica

The identification of genotypes for drought tolerance has a great importance in breeding programs. The aim of this study was to characterize genotypes of beans in response to drought tolerance in different reproductive stages through physiologic, agronomic and molecular analysis. The experiment was conducted in greenhouse, using a randomized block design with four replicates; 10 cultivars: ANFC 9, ANFP 110, BRS Esplendor, BRSMG Realce, IPR Siriri, IPR Tangará, IPR Tuiuiu, IPR Uirapuru, IAC Imperador and IAC Milênio under two conditions of irrigation: plants irrigated during their entire life cycle, and plants under irrigation suppression in the reproductive stage (R7) until 16% of field capacity, when the irrigation was restored. In the last four days of stress, the gas exchanges were analyzed, and in the last day of stress was analyzed the percentage of closed stomata in the abaxial surface of the leaves, collected in different times of the day (9h, 12h, 15h and 18h). Additionally, plant samples were collected for the following analysis: fresh and dry mass of leaves, stems and legumes, and proline content in leaves and roots. The plants were harvested at the physiological maturity and the yield components and grain yield were determined. In addition, in order to identify polymorphisms in the sequences of promoters and genes related to drought, seven pairs of primers were tested on the group of genotypes. The drought susceptibility indexes (ISS) ranged from 0.65 to 1.10 in the group of genotypes, which the lowest values observed were for IAC Imperador (0.65) and BRS Esplendor (0.87), indicating the ability of these two genotypes to maintain grain yield under water stress condition. All genotypes showed reduction in yield components under water stress. IAC Imperador (43.4%) and BRS Esplendor (60.6%) had the lowest reductions in productivity and kept about 50% of the stomata closed during all the different times evaluated at last day of irrigation suppression. IAC Imperador showed greater water use efficiency and CO2 assimilation rate under drought stress. IPR Tuiuiú, IPR Tangará and IAC Imperador had the highest proline concentrations in the roots. Under water stress condition, there was a strong positive correlation (0.696) between the percentage of stomata closed with the number of grains per plant (0.696) and the fresh mass of leaves (0.731), the maximum percentage of stomata closed 73.71% in water stress. The accumulation of proline in the root was the character that most contributed to the divergence between the genotypes under water deficit, but not always the genotypes that have accumulated more proline were the most tolerant. The polymorphisms in DNA of coding and promoting sequences of transcription factors studied in this experiment did not discriminate tolerant genotypes from the sensitive ones to water stress.

Efeitos de absorventes de umidade e de aditivos químicos e microbianos sobre o valor nutritivo, o perfil fermentativo e as perdas em silagens de capim-marandu

The objective of this trial was to evaluate the nutritional value, fermentation profile and dry matter losses of Palisadegrass silages ensiled with either dried citrus pulp, soybean hulls, chemical or microbial additives. The trial was carried out in a completely randomized experimental design and in a factorial arrangement (3 x 5), with three dry matter levels (wet forage or forage ensiled with pelleted citrus pulp or pelleted soybean hulls) and five additives (without or with the presence of bacterial inoculants or the addition of: sodium benzoate, formic acid in the concentration of 62% or 44%), totalizing 15 treatments and 60 experimental silos. The variables analyzed were: nutritional value, losses due to gases and effluents, and dry matter recovery. The use of dried citrus pulp or soybean hulls at the ensiling time increased the dry matter content (29.4 and 28,9%) and decreased the effluent production (4.1 and 3.8 kg/t of fresh matter), also providing fermentable substrate to microorganisms, resulting in increased fermentation coefficient and digestibility of silages. The use of formic acid resulted in silages with higher digestibility and increased water-soluble carbohydrates and crude protein content. This additive was also effective in reducing the losses due to gases and, as a result, increased the total dry matter recovery. The treatment containing homolactic bacteria showed similar trend of increasing the digestibility and reducing the losses due to gases. The use of sodium benzoate was less effective in altering the fermentation pattern of tropical silages. The nutritional value and total dry matter losses of silages ensiled without additives can be considered satisfactory. However, wet forage ensiled with dried citrus pulp and, mainly, with soybeans hulls showed the best results. Treatments containing formic acid had a beneficial effect on the fermentation profile of tropical grass silages.

Avaliação da produção e da qualidade do capim Panicum maximum cv. Massai

Dissertação (mestrado)—Universidade de Brasília, Faculdade de Agronomia e Medicina Veterinária, 2016.

Curva de calibração para predição do teor de óleo pela análise do espectrômetro de infravermelho próximo (NIR) em ensaios de competição de cultivares de girassol no Brasil.

2009

Avaliação das características morfogênicas de capim-sudão BRS Estribo submetido a diferentes disponibilidades hídricas.

Avaliou-se o efeito de diferentes disponibilidades hídricas sobre as características morfogênicas de capim-sudão BRS Estribo.

"O labor também é prazer": a prática e o sentido dos mutirões na comunidade Monte Sião, São Domingos do Capim - PA.

2015

Ferramentas metodológicas para transição agroecológica em unidades familiares do Pólo Rio Capim do programa PROAMBIENTE no Nordeste do Estado do Pará

No Pólo Rio Capim do programa PROAMBIENTE foram desencadeadas várias etapas metodológicas junto aos agricultores familiares como a elaboração do Plano de Desenvolvimento do Pólo (PD), Padrões de Certificação Socioambiental (PCSA), Diagnóstico Individual (DI), Plano de Utilização da unidade familiar (PU) e a construção de Acordos Comunitários (AC). Os resultados apontaram que as ferramentas metodológicas contribuem de forma significativa para produção e conservação ambiental do Pólo. Contudo, não se deve pressupor que essa metodologia seja uma solução simples para transição agroecológica. Neste sentido, é importante considerar os fatores de decisão (de caráter interno e externo) com os quais os agricultores deparam-se ao introduzir mudanças no uso da terra que serão capazes de fornecer maiores níveis produtivos e prestação de serviços ambientais o que denota a necessidade urgente de articulação entre políticas públicas agrícolas e ambientais.

Cultivares de batata com resistência a requeima para uso na agricultura familiar.

2015

Resistência genética de cultivares e linhagens de tomateiro à "murcha bacteriana".

Um dos principais entraves em cultivar o tomateiro no trópico úmido está relacionado à presença do patógeno Ralstonia solanacearum, pois este é de ocorrência natural nos solos da região Amazônica. Foram estimados os níveis de resistência genética à bactéria R. solanacearum de linhagens de tomate do grupo Yoshimatsu e a produtividade em comparação a outras variedades disponíveis no mercado. O ensaio foi realizado em uma unidade de produção de um agricultor familiar na qual foram avaliados 8 genótipos de tomate: Santa Cruz Kada, Yoshimatsu 4-11, (L1-2002), (L2-2002), (L3-2002), (L4-2002), (L5-2002) e (L6-2002). Foram avaliados o índice de sanidade (IS) e a produção total dos frutos. A cultivar Santa Cruz Kada apresentou maiores níveis de incidência ao patógeno em relação às demais cultivares. No entanto, ao avaliar o parâmetro de produtividade, a cultivar (L6-2006) foi superior às demais.