Animal production potential of some new Leucaena accessions in the Markham valley, Papua New Guinea

Signal grass pastures were oversown with four Leucaena spp. planted in hedgerows and evaluated for their agronomic productivity and ability to support steer liveweight gains. Each Leucaena sp. (L. leucocephala, L. pallida, L colli. nst. i., L. trichandra) was planted as seedlings into two I ha paddocks in rows 5 m apart, with I m spacing between trees. Cattle were rotationally grazed on the 2 replicates of each species, as well as on two I ha paddocks of a signal grass on y (Brachiaria decumbens) control, over a 243-day period at a stocking rate of 3 steers/ha. Mean presentation yield and herbage allowance of the Leucaena accessions over the grazing period were highest for L pallida (1100 kg/ha and 0.8 kg DM/kg LW, respectively), followed by L. leucocephala (700 kg/ha and 0.5 kg DM/kg LW), L. collinsii (700 kg/ha and 0.4 kg DM/kg LW) and L. trichandra (300 kg/ha and 0.2 kg DM/kg LW). Despite only moderate presentation yields and herbage allowances, steers grazing L. leucocephala and L. collinsii accessions produced the highest mean liveweight gains (LWG) of 0. and 0.56 kg/hd/d, respectively. While L. pallida produced the highest DM yields, it supported the lowest LWG of 0.36 kg/hd/d. The mean LWGs of steers grazing L. trichandra and the control (grass only) treatments were similar at 0.48 kg/ hd/d. The possible reasons for the differences in steer performance on the different Leucaena accessions are discussed.

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.

Biogenic opal and diatoms in surface sediments of the South Western Atlantic

Based on 66 surface sediment samples collected in the SW Atlantic Ocean between 27 and 50°S, this study presents an overview of the spatial distribution of biogenic opal and diatom concentrations, and diatom assemblages. Biogenic opal has highest values in the deepest, pelagic stations and decreases toward the slope. Diatoms closely follow the spatial trend of opal. Diatom assemblages reflect the present-day dominant hydrographical features. Antarctic diatoms are the main contributors to the preserved diatom community in core top sediments, with coastal planktonic and tropical/subtropical diatoms as secondary components. Dominance of Antarctic diatoms between 35 and 50°S in the pelagic realm mirrors the northward displacement of Antarctic-source water masses, characterized by high nutrient content and low salinity. Northward of ca. 35°S, the highest contribution of tropical/subtropical, pelagic diatoms, typical for nutrient-poor and high salinity waters, matches the main southward path of the Brazil Current. Mixing of Antarctic and tropical waters down up to 45°S is clearly illustrated by the diatom assemblage. Concentrations of biogenic opal and diatoms rather reflect the path of predominant water masses, but are less correlated with surface water productivity in the SW Atlantic.

Distribution of diatom species as abundance estimates from vertical multinet hauls from 150 m water depth in the Indian Ocean

During the Indian Ocean Expedition of R/V METEOR phytoplankton samples were taken with a multiple closing net (Multinet) at 103 stations. In this material the diatoms were investigated. In all 247 taxa could be identified which belong to 242 species and 5 varieties of formae of 80 genera. Of these 1 variety, 15 pecies, and 3 genera are newly described. New combinations were made for 18 species, and a number of old combinations was reinstated.

Relative abundance of euphausiids (Crustacea) in water samples of the Arabian Sea (Table 2)

In the present paper, the ecology and feeding habits of euphausiids are described. The samples were taken at the time of the NE-monsoon (1964/65) by R. V. "Meteor" in the Arabian Sea and adjacent waters. 24 species were determined. According to distribution of the species, the following marine areas can be distinguished: Arabian Sea: 24 species, dominant are Euphausia diomedeae, E. tenera, E. distinguenda, Stylocheiron carinatum. Gulf of Aden: 10 species, dominant are Euphausia diomedeae, E. distinguenda. Red Sea: 6 species, dominant are Euphausia diomedeae, E. distinguenda. Gulf of Oman : 5 Species, dominant are Euphausia distinguenda, Pseudeupbaufia latifrons. Persian Gulf: 1 species - Pseudeuphausia latifrons. The total number of euphausiids indicate the biomass of this group. High densities of euphausiids (200-299 and > 300 individuals/100 m**3) occur in the innermost part of the Gulf cf Aden, in the area south of the equator near the African east coast, near Karachi (Indian west coast) and in the Persian Gulf. Comparison with data relating to production biology confirms that these are eutrophic zones which coincide with areas in which upwelling occurs at the time of the NE-monsoon. The central part of the Arabian Sea differs from adjacent waters by virtue of less dense euphausiid populations (> 199 individuals/100 m**3). Measurements relating to production biology demonstrate a relatively low concentration of primary food sources. Food material was ascertained by analysis of stomach content. The following omnivorous species were examined: Euphausia diomedeae, E. distinguenda, E. tenera, Pseudeuphausia latifrons and Thysanopoda tricuspidata. Apart from crustacean remains large numbers of Foraminifera, Radiolaria, tintinnids, dinoflagellates were found in the stomachs. Quantitatively crustaceans form the most important item in the diet. Food selection on the basis of size and form appears to be restricted to certain genera of tintinnids. The genera Stylocheiron and Nematoscelis are predators. Only crustacean remains were found in the stomachs of Stylocheiron abbreviatum, whereas Radiolaria, Foraminifera and tintinnids occurred to some extent in Nematasceli sp. Different euphausiids in the food chain in the Arabian Sea. In omnivorous species the position is variable, since they not only feed by filtering autotrophic and heterotrophic Protista, but also by predation on zooplankton. Carnivorous species without filtering apparatus feed exclusively on zooplankton of the size of copepods. Only these species are well established as occupying a higher position in the food chain. The parasitic protozoan Tbalassomyces fagei was found on Euphausia diomedeae, E. fenera, E. distinguenda and E. sanzoi.

Competências inovativas e a acumulação do conhecimento: um estudo de caso em uma inovação tecnológica da pecuária de corte

Este artigo tem como objetivo descrever o processo de gerar competências inovadoras na Empresa Brasileira de Pesquisa Agropecuária. No inicio de 1980, o centro de pesquisa da Embrapa Gado de Corte estava engajado no projeto Marandu - Brachiaria brizantha - originalmente uma planta nativa da África, potencialmente usada para alimentação do gado. Atualmente é responsável por cerca de 40% das sementes de forrageiras vendidas no Brasil, cultivada em cerca de 70 milhões de hectares de pastagens no país. Uma abordagem qualitativa foi definida para a pesquisa exploratória, e delineamento de estudo de caso. Foram feitas entrevistas semiestruturadas com os pesquisadores envolvidos no projeto e examinado os processos de geração, armazenamento, distribuição e aplicação do modelo de conhecimento tecnológico aplicado pela Embrapa. Os resultados obtidos evidenciam a relevância do ciclo de geração de competências nos processos da gestão do conhecimento, essenciais nas tecnologias da pecuária de corte do agronegócio.

Efectos de los sistemas de cultivo-arboles-pastos sobre la erosión laminar y la calidad de suelo en la micro cuenca Tecomapa, municipio de Somotillo-Nicaragua

Con el objetivo de evaluar los efectos de los sistemas de cultivo - arboles - pastos sobre la erosión laminar y la calidad de suelo, en tres fincas de la micro cuenca Tecomapa, municipio de Somotillo - Nicaragua ; f ueron estable cidas en cinco usos de la tierra: q uema tradicional (Q); sistema agroforestal Quesungual (SAQ ); bosque secundario (Bs ); potreros mejorados con Brachiaria sp - Marandú , (Pm); y sistema silvopastoril (SSP), 30 sub parcelas de 10 m 2 con 10 varillas cada una , y monitoreados diez indicadores de calidad de suelo durante 2011, 2012 y 2013 . Como resultado , la tasa de erosión neta positiva (ganancia) fue clasificada de moderada (10 a 50 t ha - 1 a - 1 ) en los sistemas de BS y Pm, y de alta (50 a 200 t ha - 1 a - 1 ) en los sistemas SAQ y SSP . La tasa de erosión neta (pérdida) fue clasificada de moderado únicamente en el sistema de q uema agrícola (28.3 t ha - 1 a - 1 ) . Procesos qu e ocurrieron mayormente en pendientes de 26 y 57% . La tasa de erosión dentro ( ganancia ) representó un 61.5% del total de la erosión neta, fenómeno asociado al uso de la tierra y probablemente a la forma del micro relieve. Estas tasas de erosión dentro de las parcelas ocurrieron mayormente en pendientes de 15 y 52%, en las partes bajas . La calidad de los suelos fue influenciada por l os contenidos de MOS , contenidos que fueron mayores a 4000 kg ha - 1 en los sistemas SAQ, SSP y Bs . Este indicador fue correlacionado negativamente con el incremento de arcilla en el horizonte superficial de los suelos utilizados en pasturas por erosión previa . Finalmente, l os indicadores de calidad de suelo que incrementan el rendimiento del cultivo de maíz y frijol fueron los altos contenidos de MOS, tasas de infiltraciones rápidas , y la presencia de sue los con pendientes altas únicamente para frijol

Integração lavoura-pecuária-floresta como estratégia para aumentar a produtividade e prover serviços ambientais no noroeste do Paraná.

RESUMO: Os solos da região Noroeste do Paraná apresentam cerca de 85 a 90% de areia e níveis críticos de nutrientes, conferindo alta suscetibilidade à erosão e baixa capacidade de armazenamento de água. Além disso, a região apresenta clima quente, tornando-a bastante vulnerável a estresses abióticos. Uma das estratégias para aumentar a produtividade e, ao mesmo tempo, incrementar serviços ambientais é aumentar a diversidade de atividades, por meio do sistema de integração lavoura-pecuária-floresta (iLPF). O sistema iLPF pode conferir maior taxa de sequestro de carbono, conservação da biodiversidade e melhoria da qualidade do solo, água e ar, em comparação a sistemas não integrados. No município de Santo Inácio, PR, foram conduzidas por cinco anos duas áreas com sistema iLPF. Nos três primeiros anos de condução, foi possível conciliar a produção de grãos (soja), forragem (Brachiaria ruziziensis e B brizantha ) e madeira (eucalipto), sem que um componente prejudicasse o outro. A partir do terceiro ano, as árvores interferiram expressivamente na produtividade de grãos e forragem, indicando a necessidade de redução do número de árvores por área. O iLPF é um sistema de produção relevante para aumentar a provisão de bens e serviços ecossistêmicos na região Noroeste do Paraná, mas que ainda precisa de ajustes tecnológicos para incrementar os ganhos econômicos e ambientais. ABSTRACT: Most soils in Northwest of Paraná state, Brazil, are sandy (85 to 90% sand), with critical nutrient levels, high susceptibility to erosion and low water storage capacity Moreover, the region?s warm weather confers to these soils high vulnerability to abiotic stresses The diversification of production via adoption of integrated cropping-livestock-forestry (ICLF) systems is an important strategy to increase productivity and, simultaneously enhance ecosystem services. ICLF systems can increase carbon sequestration, conserve biodiversity and improve soil, water and air quality, compared with specialized production systems. Two trials were carried out for five years using ICLF in Santo Inácio county in Paraná state, Brazil. In the first three years, it was possible to harmonize production of grains (soybean), fodder (Brachiaria ruziziensis and brizantha) and wood (Eucalyptus) without negative effects of three components on each other. After the third year, the trees significantly reduced grain yield and fodder production, indicating the need for thinning to reduce tree interference. The ICLF system is relevant to increase the delivery of ecosystem goods and services in Northwestern Paraná, though technological adjustments are needed to increase its economic and environmental gains.

Ruminal methane emission by dairy cattle in southeast Brazil.

ABSTRACT: Ruminal gases, particularly methane, generated during the fermentative process in rumen, represent a partial loss of feed energy and are also pointed to as an important factors in greenhouse effect. This study aimed at quantifying methane (CH 4) emission rates from lactating and dry cows and heifers, 24 month-old in average, on pasture under Southeast Brazil tropical conditions, using the tracer gas technique, sulphur hexafluoride (SF 6), four animals per category, distributed in four blocks. Measurements were performed in February and June, 2002, with Holstein and Brazilian Dairy Crossbred (Holstein ¾ x Gir (Zebu) ¼), maintained on fertilized Tanzania-grass (Panicum maximum Jacq. cv. Tanzania) and fertilized Brachiaria-grass (Brachiaria decumbens cv. Basilisk) pastures. Heifers of both breeds were maintained on unfertilized Brachiaria-grass to simulate conditions of extensive cattle farming systems. CH 4 and SF 6 levels were measured with gas chromatography. Differences in CH4 emissions were measured (p < 0.05) for genetical groups. Holstein produced more methane (299.3g day?1) than the Crossbred (264.2 g day?1). Lactating cows produced more methane (353.8 g day?1) than dry cows (268.8 g day?1) and heifers (222.6 g day?1). Holstein, with greater milk production potential, produced less CH4 (p < 0.05) per unit of dry matter intake (19.1 g kg?1) than the Crossbred (22.0 g kg?1). Methane emission by heifers grazing fertilized pasture (intensive system) was 222.6 g day?1, greater (p < 0.05) than that of heifers on unfertilized pasture (179.2 g day?1). Methane emission varied as function of animal category and management intensity of production system.

Microwave-assisted solvent extraction and analysis of shikimic acid from plant tissues.

A better method for determination of shikimate in plant tissues is needed to monitor exposure of plants to the herbicide glyphosate [N-(phosphonomethyl)glycine] and to screen the plant kingdom for high levels of this valuable phytochemical precursor to the pharmaceutical oseltamivir. A simple, rapid, and efficient method using microwave-assisted extraction (MWAE) with water as the extraction solvent was developed for the determination of shikimic acid in plant tissues. High performance liquid chromatography was used for the separation of shikimic acid, and chromatographic data were acquired using photodiode array detection. This MWAE technique was successful in recovering shikimic acid from a series of fortified plant tissues at more than 90% efficiency with an interference-free chromatogram. This allowed the use of lower amounts of reagents and organic solvents, reducing the use of toxic and/or hazardous chemicals, as compared to currently used methodologies. The method was used to determine the level of endogenous shikimic acid in several species of Brachiaria and sugarcane (Saccharum officinarum) and on B. decumbens and soybean (Glycine max) after treatment with glyphosate. The method was sensitive, rapid and reliable in all cases.

Bioecology of Spodoptera frugiperda (Smith, 1757) in different cover crops.

The objective of this work was to evaluate the biological variables of Spodoptera frugiperda on species of cover crops. The experiments were conducted in laboratory and greenhouse using the following species: sunflower (Helianthus annuus), sun hemp (Crotalaria juncea), brachiaria (Urochloa decumbens e Urochloa ruziziensis), millet (Pennisetum americanum), black oat (Avena stringosa), white lupin (Lupinus albus), forage turnip (Rafanus sativus) and maize (Zea mays). In laboratory the S. frugiperda larval survival varied from 57%, on L. albus, to 93% on H. annuus and the survival of the pre-imaginal phase varied from 45% on U. decumbens to 81.6% on Z. mays. On C. juncea the larval biomass was lower and the development period of the young and larval stage was higher. The adaptation index was less on C. juncea in greenhouse and laboratory. In greenhouse the larval survival at 14 days was similar for all plants and at 21 days was the lowest on C. juncea. There was less accumulation of biomass at 14 days on C. juncea and at 21 days on C. juncea and A. stringosa. Regarding damage, C. juncea presented less susceptibility to Spodoptera frugiperda attack, which together with the other evaluated parameters, indicated this plant as the most appropriate for soil cover before cultivation of maize.

Braquiária na agropecuária brasileira: uma história de sucesso.

2013

Identificação e características de forrageiras perenes para consórcio com milho.

2013

Introdução de gramíneas visando resistência a cigarrinha-das-pastagens no Estado do Acre.

Devido a Brachiaria decumbens ser a gramínea de maior preferência para a implantação de pastagens nos últimos 10 anos no Estado do Acre, os problemas com ataques severos da cigarrinha-das-pastagens estão se intensificandonos últimos 3 anos. Isto evidencia a necessidade de que sejam encontradas outras opções de gramíneas resistentes e/ou tolerantes para a formação ou reforma de áreas de pastagens efetuando-se, desta forma, um controle integrado da praga.