Produção de silagem de milho em consórcio com braquiárias e sobressemeadura de aveia para terminação de cordeiros

Pós-graduação em Zootecnia - FMVZ

Ferrugem do Eucalipto: favorabilidade climática e métodos de aplicação de fungicida para controle

Pós-graduação em Agronomia (Proteção de Plantas) - FCA

Emissão de dióxido de carbono e estoque de carbono em sistemas convencionais e alternativo de produção agropecuária no Nordeste paraense

A aplicação de técnicas menos agressivas ao meio ambiente, como o uso de sistemas alternativos (corte e trituração), no lugar dos sistemas convencionais (corte-e-queima), além de favorecer o equilíbrio dos ciclos biogeoquímicos em áreas florestais, contribui para a mitigação das mudanças climáticas. O objetivo deste estudo foi estimar a emissão e o estoque de carbono do solo em sistemas de produção agropecuária em unidades rurais familiares do Nordeste paraense. Os estudos foram conduzidos em área de agricultor familiar no Município de Mãe do Rio, com temperatura média anual de 25 a 28°C, precipitação pluviométrica acimade 2500 mm e com solo predominante do tipo Latossolo Amarelo distrófico de textura média a argilosa. Foram selecionados 3 sistemas de uso da terra (cultivo com Schizolobium amazonicum, roça e silvipastoril) e mais uma área de referencia (floresta secundária), com 4 parcelas, medindo 20 m x 20 m cada. Foram avaliados a emissão de CO2 do solo, estoque de carbono no solo, estoque da liteira no solo e estoque de carbono na liteira. Os dados foram submetidos à Análise de Variância (ANOVA) e à comparação das médias pelo teste de Tukey, ao nível de 5%. Em todos os sistemas avaliados, as maiores emissões de CO2 do solo, observadas no período chuvoso, foram no sistema silvipastoril (5,02 Wmol CO2 m^-2 s^-1), em comparação à área da floresta secundária (3,56 Wmol CO2 m^-2 s^-1). De todas as áreas estudadas a maior emissão anual foi encontrada no sistema silvipastoril. O estoque de carbono no solo foi maior na área da floresta secundária, com total de 157± 31,10 Mg ha^-1 (0-100 cm). O maior estoque de liteira no solo encontrado foi para a fração da liteira não-lenhosa, em todos os sistemas agropecuários e floresta secundária. O maior estoque de carbono na liteira não-lenhosa total foi observada no mês de janeiro/2010, com média geral de 4,31± 3,0 Mg ha^-1, em todos os sistemas avaliados. Os sistemas de uso da terra que não utilizam o fogo no preparo da área, como os sistemas alternativos de corte-e-trituração, além de contribuirem para a mitigação das mudanças climáticas, ajudam na manutenção do funcionamento adequado dos ciclos biogeoquímicos nos ecossistemas terrestres.

Adubação nitrogenada e potássica na qualidade de sementes de Urochloa brizantha cvs. Marandu, Xaraés e BRS Piatã

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Initial height of pasture deferred and utilized in winter and tillering dynamics of signal grass during the following spring

Tillering dynamics during regrowth in the spring (September to December 2009) on signal grass (Brachiaria decumbens cv. Basilisk) pastures deferred in the beginning of April 2009 is evaluated. Four pasture heights were evaluated at the beginning of deferment (10, 20, 30 and 40 cm). The experimental design consisted of completely randomized blocks with two replications. Rise in pasture height at the beginning of deferment decreased the appearance rate, increased the mortality rate and reduced the survival rate, the balance between appearance and mortality and the stability index of the tiller population at the beginning of the spring. Pastures deferred at initial height of 30 and 40 cm presented relatively stable tiller appearance rate between the beginning and end of spring. However, these pastures presented greater mortality rate, lower survival rate, lower balance between appearance and mortality and lower stability index of the tiller population at the beginning of spring when compared to rates at the end of spring. Pastures managed with shorter initial heights (10 and 20 cm) provided more tissue renewal in the subsequent growth season after their utilization in the winter.

Características estruturais do dossel, produção de forragem e desempenho de cordeiros em pastos de tifton 85 sob lotação intermitente

Pós-graduação em Zootecnia - FCAV

Photodynamic Therapy in Pythium insidiosum - An In Vitro Study of the Correlation of Sensitizer Localization and Cell Death

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Root system and root and stem base organic reserves of pasture Tanzania grass fertilizer with nitrogen under grazing

The goal of this study was to evaluate the concentrations of non-structural carbohydrate (NSC) and of total nitrogen (N), as well as, to evaluate the root system in Tanzania-grass pastures fertilized with doses of urea in fall, spring and summer. The experiment was conducted at the Experimental Farm of Iguatemi, Maringa, Parana, Brazil, from March 2007 to March 2008. The experimental design was complete random blocks with subplots and four repetitions. The plots showed doses of N (50, 100 e 150 kg ha(-1) of N) plus the control (no N fertilization), and the subplots the season of the year. Root samples were taken at depths of 0-10, 10-20 and 20-40 cm. Root biomass showed a trend for mass accumulation up to a dosage of 100 kg ha(-1) for all seasons evaluated. Also, about 80% of the root system of Tanzaniagrass plants was found on the 0-10 cm layer for all dosages of N. Nitrogen fertilizer above 100 kg ha(-1) may foster fast forage plant growth reducing its NSC root storage capacity although favoring NSC and total N storage at stem base. NSC and total N concentrations were highest in fall, demonstrating that its usage is greater in spring due to the weather conditions being favorable to plant growth. In the regrowth, the largest reserve of total N was at the 0-10 cm root layer and the largest NSC reserve is at stem base.

CONTRIBUTION OF BASAL AND AERIAL TILLERS IN DYNAMICS OF HERBAGE PRODUCTION OF SIGNALGRASS AFTER GRAZING DEFERRED

During the spring, the understanding of regrowth in basal and aerial tillers of deferred pasture in winter it is necessary. Thus, the objective was to evaluate the morphogenesis and herbage accumulation during spring in Brachiaria decumbens cv. Basilisk (signalgrass) pasture used under deferred grazing in winter. The basal and aerial tillers in same pasture were evaluated. The signalgrass was managed with grazing cattle and with an average height of 25 cm. The randomized block design with three replications was adopted. The leaf appearance rate, phyllochron and the numbers of expanded, expanding and live leaves did not differ between basal and aerial tillers. The aerial tiller possessed lower rates of leaf senescence, of leaf elongation and of stem elongation, as well as lower number of dead leaf and stem and leaf lamina lengths, compared to basal tiller. The leaf lifespan was higher in aerial tillers than at basal. The basal tiller also contributed to higher rates of tissue growth and forage accumulation in pasture when compared to aerial tiller. After deferred grazing during the spring, the aerial tiller has low participation in forage production of signalgrass pasture.

TANZANIA GRASS STRUCTURE GRAZED BY GOATS MANAGED WITH DIFFERENT RESIDUAL LEAF AREA INDEX UNDER INTERMITTENT STOCKING

The objective of this study was to evaluate the structure of Tanzania grassland grazed by goats managed with different residue leaf area index (RLAI) under intermittent stocking. The experiment was carried out from February to August, 2008. The treatments consisted of three different targets RLAI (0.8, 1.6 and 2.4) and 95% light interception (LI) criterion determined the rest period. Forage samples were collected at average height sampling points and weighed. Subsequently, a smaller sample was removed to separate the morphological components (leaf, stem and dead material) and to determine the structural and productive features. The canopy architecture was evaluated by the method of inclined point quadrat. The pre-grazing height in the paddocks were significantly different among treatments. RLAI influenced dry matter contents of green forage, leaf, stem and total, with the exception of dry matter of dead material, where the lowest values were observed for 0.8 RLAI. Thus, RLAI modifies canopy structure and is sensitive to canopy height changes throughout the year. Pasture regrowth is not compromised by residual leaf area indexes between 0.8 and 2.4, when climatic factors are not limiting.

Desempenho de híbridos intraespecíficos de Brachiaria decumbens desenvolvidos por seleção recorrente recíproca

Pós-graduação em Agronomia (Genética e Melhoramento de Plantas) - FCAV

Degradabilidade ruminal da matéria seca de folhas e colmo de genótipos de Cynodon spp. em quatro idades de rebrota

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Comparison of different irrigants in the removal of endotoxins and cultivable microorganisms from infected root canals

This study was conducted to compare the effectiveness of different irrigants used to remove endotoxins and cultivable microorganisms during endodontic therapy. Forty root canals were contaminated and divided into groups according to the irrigant: 2% NaOCl + surfactant, 2% CHX, 2.5% NaOCl, and pyrogen-free saline solution (control). Samples were collected after root canal contamination (S1), after instrumentation (S2), and 7 days after instrumentation (S3). Microorganisms and endotoxins were recovered from 100% of the contaminated root canals (S1). At S2, 2% NaOCl + surfactant, 2% CHX, and 2.5% NaOCl were able to completely eliminate cultivable microorganisms. At S3, both 2% CHX and 2.5% NaOCl were effective in preventing C. albicans and E. coli regrowth, but E. faecalis was still detected. No microorganism species was recovered from root canals instrumented with 2% NaOCl + surfactant. At S2, a higher percentage value of endotoxin reduction was found for 2% NaOCl + surfactant (99.3%) compared to 2% CHX (98.9%) and 2.5% NaOCl (97.18%) (p < 0.05). Moreover, at S3, 2% NaOCl + surfactant (100%) was the most effective irrigant against endotoxins. All irrigants tested were effective in reducing microorganisms and endotoxins from root canals. Moreover, 2% NaOCl + surfactant was the most effective irrigant against endotoxins and regrowth of microorganisms.

Eficácia do glyphosate e 2,4-d no controle de commelina villosa

The aim of this study was to evaluate the efficacy of glyphosate and 2,4-D alone and in combination, in the control of Commelina villosa. We studied two methodologies for evaluating herbicide absorption in eight time intervals for washing (simulating rainfall after application) and cutting of leaves (simulating abortion as a defense strategy): 2, 4, 6, 8, 12, 24 and 48 hours after herbicide application, and a treatment without washing or cutting the leaves in a completely randomized design with four replications in a 3 x 7 + 1 factorial design (three herbicides x seven periods – hours after application). Herbicides and doses tested were: glyphosate (1,440 g ha-1), 2,4-D (720 g ha-1) and a mixture of glyphosate + 2,4-D (1,080 + 720 g ha-1). The simulation of rain interfered negatively in the plant control with glyphosate. The control with the herbicide 2,4-D was affected only for the period of 2 hours. Periods of rain simulation did not influence the control of plants with a mixture of glyphosate + 2,4-D. For the study with the cutting of treated leaves, all treatments regardless of the period of cutting the leaves were influenced negatively in terms of plant control, the plants showing regrowth when treated with 2,4-D alone.

Produção e qualidade de silagens de sorgo em sistema de integração lavoura-pecuária no cerrado de baixa altitude

Pós-graduação em Agronomia - FEIS