RESUMO -Das estratégias adotadas pelas plantas invasoras para dominância em comunidades vegetais a liberação de aleloquímicos se sobressai. Estes compostos encontram-se em qualquer parte vegetal, principalmente em exsudatos de raízes, folhas e seus degradados sendo liberados no ambiente através de emanações voláteis ou solúveis, translocados em água. O capim-annoni-2, Eragrostis plana Nees, é uma Poaceae exótica, invasora de pastagens e com potencial alelopático. Para testar este efeito coletaram-se caules e folhas da parte mediana da planta de capim-annoni-2, em caixas gerbox, usando papel germitest como substrato sobre o material picado de capim-annoni-2. Foram colocadas para germinar 100 sementes das espécies: Termos para indexação: espécie invasora, exsudato, níveis de cobertura, decomposição, germinação. ALELOPATHIC POTENTIAL OF CAPIM-ANNONI-2 (Eragrsotis plana Nees) ON THE SEED GERMINATION OF SUMMER PERENNIAL GRASSESABSTRACT -Among plant strategies to invade and dominate the plant community, the release of alelochemicals is prominent. These compounds are present in all plant parts, principally, in root exudates, leaves and their degraded parts. They are released in the environment through volatile or soluble emanations, translocated in water. Capim-annoni-2 is an invasive exotic Poaceae of rangeland vegetation with allelopatic potential. To test this effect, plant structures from the mid part of capimannoni-2 were collected and cut in small pieces of 0.5cm and placed in three covering levels of 0, of m Flüggé, P. regnellii Mez, B. K. Simon and S. W. L.
-This research aimed to determine the soil seed bank and its relationship with environmental factors that have an influence in the distribution of the vegetation above the ground in an excluded area of natural grassland in the South of Brazil. Most of the 122 identified species in the seed bank were perennials. Data analysis indicated three distinct community groups, according to the size and composition of the soil seed bank in lowlands with permanent wet soils, in lowlands and in other areas. In general, lowlands were characterized by low-fertility soils, high moisture and aluminum contents, being spatially homogeneous habitats and, therefore, more restricted to vegetation heterogeneity than other parts of the relief. Environmental factors most associated with soil seed bank size and composition were relief position and their co-related soil variables such as: soil moisture content, potassium content, organic matter, basic saturation of cation exchange soil capacity, exchangeable basics sum of the soil and clay soil content. According to that, relief position, associated with combined effects of soil chemical properties related to it, determines the observed variation pattern of the soil seed bank, as a reflection of the vegetation above the area.
The successful achievement of a highly productive understorey pasture in silvopastoral systems depends on the use of well-adapted forage genotypes, showing good agronomic performance and persistence under shading and grazing. In this study, the herbage dry matter yield (DMY) and nitrogen nutrition dynamics were determined in three native warm-season grasses (Paspalum regnellii, Paspalum dilatatum and Paspalum notatum) and a forage legume (Arachis pintoi) under two shading levels compared with full sun. The experiment was conducted in the Campanha region, Bagé, state of Rio Grande do Sul, Brazil, during two evaluation cycles (2008/2009 and 2009/2010). Three shade cloth levels (0%, 50% and 80% of light restriction) were applied to the forage genotypes in a split plot design, in which shading levels were the main plot and forage genotypes were the subplots, with three replications. P. regnellii showed the highest accumulated DMY (1500 and 1700 g m-2, respectively, for the first and second evaluation cycles) at all shading levels and showed no DMY decreased under the heavy shade (80%). Average DMY over the four genotypes under the 50% shade level was higher or equal compared with full sun. Influence of rainfall was observed on the DMY performance of all genotypes: the positive effect of moderate shading (50%) on P. dilatatum and P. notatum DMY was associated to a low soil water availability status. Increased shading level resulted in high nitrogen nutrition index values on grasses, in comparison with full sun. All genotypes performed well under the moderate shading level, but the DMY of both P. regnellii and P. dilatatum and the herbage N content in P. notatum and A. pintoi of all genotypes stood out, showing that those main genotypes are promising to grow in silvopastoral systems at the Campanha region in southern Brazil
RESUMO -Objetivou-se com este trabalho avaliar o efeito do processo de digestão de bovinos sobre o poder germinativo de sementes de capim-annoni-2 (Eragrostis plana Ness) recuperadas nas fezes. As sementes (6 g, 27.273 sementes) foram colocadas no saco ventral do rúmem de oito novilhos fistulados, mantidos em gaiolas para ensaios metabólicos. Quarenta e três por cento das sementes fornecidas aos animais foram recuperadas nas fezes: aquelas recuperadas nos três primeiros dias corresponderam a 97,2% da quantidade de sementes fornecidas. Somente 7,2% das sementes recuperadas, equivalente a 3,1% da quantidade de sementes fornecidas, apresentaram viabilidade. O tempo de permanência no trato digestivo foi a principal causa do desaparecimento das sementes consumidas e da perda de seu poder germinativo. A ausência de sementes de capim-annoni-2 nas fezes ocorre a partir do oitavo dia após a ingestão, assim, bovinos devem permanecer em quarentena por sete dias em área livre de capim-annoni-2 para limpeza do trato digestivo.Palavras-chave: campo natural, dispersão de invasoras, ingestão de sementes, invasão biológica, transporte de sementes Germination of capim-annoni-2 (Eragrostis plana Ness) seeds recovered in bovine fecesABSTRACT -This work was carried out with the objective of evaluating the effect of the bovine digestion process on the germination capacity of the capim-annoni-2 (Eragrostis plana Ness) seeds recovered in feces. The seeds (6 g, 27,273 seeds) were placed in a ruminal ventral sack of eight fistulated steers kept in pen trial. Forthy-three percent of the offered seeds were recovered in the feces. Seeds recovered in the first three days corresponded to 97.2% of the offered seeds. Only 7.2% of the recovered seeds germinated and represented 3.1% of the offered seeds. The permanence time in the digestive trait was the main cause for the disappearance of consumed seeds and for the loss in their germination capacity. The absence of capim-annoni-2 seeds in the feces occurs in the eighth day after ingestion, then, bovines should be kept in quarantine for seven days in an area free of capim-annoni-2 seeds to clean their digestive trait.
RESUMO -Este trabalho foi realizado a campo com o objetivo de avaliar o comportamento de pastejo de ovinos conduzidos em azevém anual (Lolium multiflorum Lam.) nos estádios vegetativo, pré-florescimento e florescimento. Ovelhas ao final da gestação e início de lactação foram mantidas em um potreiro de 1,3 ha, onde foram avaliados o tempo de pastejo, taxa de bocados, peso de bocados e a relação folha:caule da forragem disponível e da forragem ingerida, estimada por coleta manual. Foram observados tempos de pastejo diário de 9,65; 10,97 e 10,68 h, taxas de bocados de 52,65; 51,93 e 40,63 bocados/min e pesos de bocados de 0,064; 0,055 e 0,048 g/bocado, que resultaram em taxas de consumo de forragem de 4,48; 3,91 e 2,72% do peso vivo/dia, nos estádios vegetativo, pré-florescimento e florescimento, respectivamente. Estas evoluções foram acompanhadas por diminuições das relações folha:caule da forragem disponível (3,6:1; 1,44:1 e 0,56:1), evidenciando a limitação qualitativa da forragem no estádio de florescimento. Estes dados demonstraram que, até o estádio de pré-florescimento, as estratégias desenvolvidas pelos animais permitiram adequado consumo de forragem, enquanto, no estádio de florescimento, a baixa qualidade da pastagem determinou queda no consumo, considerado insuficiente para atender as necessidades nutricionais de ovelhas lactantes com seus respectivos cordeiros.Palavras-chave: azevém, coleta manual, comportamento animal, consumo, estágios fenológicos, ovinos Sheep Behavior at the Pregnancy and at the Lactation Grazing on Different Phenological Stages of Annual RyegrassABSTRACT -This work was carried out at the field to evaluate the grazing sheep behavior conducted in annual ryegrass (Lolium multiflorum Lam.) on vegetative, pre-flowering and flowering stages. Ewes at the end of pregnancy and at the beginning of lactation maintained in a 1.3 ha paddock were evaluated in terms of grazing time, bite rate, bite size, leaf:stem ratio of ingested pasture estimated by hand-plucking method. Daily grazing time/h of 9.65, 10.97 and 10.68, bite rates/min of 52.65, 51.93 and 40.63 and the bite weight g/bite of 0.064, 0.055 and 0.048 were observed for vegetative (VS), pre-flowering (PS) and flowering stages (FE), respectively. This behavior resulted in forage intake rates of 4.48%, 3.91% and 2.72% of body weight on VS, PS an FS, respectively These evolutions were accompanied by reduction of the leaf:stem ratio of available forage (4.36:1, 1.11:1 and 0.17:1) which were in accordance to the qualitative limitation that occurs in the flowering stage. These data showed that until pre-flowering stage, the strategies desenvolved by the animals allowed an adequate intake forage, while that in the flowering stage the low quality pasture determinated a decrease intake, being this considerate insufficient to attend nutritional necessities of lactating ewes and respective lambs.
RESUMO -Este trabalho foi realizado com o objetivo de avaliar o comportamento ingestivo no período diurno de ovelhasCorriedale em final de gestação e início de lactação sob pastejo em uma área de 1,3 ha de azevém anual (Lolium multiflorum Lam.) nos estádios vegetativo, pré-florescimento e de florescimento. Foram determinados o tempo de pastejo, a taxa de bocado, o tamanho de bocado, o teor de PB da forragem e os consumos de MS e PB. Os maiores tempos de pastejo e de consumo de MS e PB, para os três estádios do azevém, foram observados ao final da tarde. Nos estádios vegetativo e pré-florescimento, os tempos de pastejo e os consumos de MS e PB registrados no início da manhã (7 às bite rate, bite weight, crude protein (CP) content per bite, and forage dry matter (DM) and CP intakes were measured. The longest grazing time and the greatest forage DM and CP intakes were observed at late afternoon on all three phenological growth stages of annual ryegrass. Grazing time and intakes of CP and DM observed early in the morning (7:00 to 7:50 AM)during the vegetative and pre-flowering phenological growth stages were similar to those registered at late afternoon. In addition, the greater bite rates and bite weights observed at pre-flowering plus the longer grazing time at this growth stage resulted in the highest diurnal intake of forage DM. The shortest grazing times were found from 8:00 to 9:50 AM, from 8:00to 8:50 AM and from 12:00 AM to 12:50 PM, and from 7:00 to 8:50 AM, respectively, for the vegetative, pre-flowering, and flowering phenological growth stages, which coincided with the lowest intakes of forage DM and CP.
Avaliou-se o efeito do sombreamento provocado por duas densidades arbóreas em uma floresta de Pinus elliottii Engelm. com 10 anos de idade sobre o rendimento e o valor nutritivo da forragem de três gramíneas de ciclo hibernal. Como tratamentos, avaliou-se a combinação de dois fatores (3 x 3) em um delineamento experimental de parcelas subdivididas com três repetições, no qual as parcelas foram as condições luminosas (proporcionadas por duas densidades arbóreas: 555 e 333 árvores/ha e luz solar plena) e as subparcelas as espécies forrageiras azevém-anual (Lolium multiflorum Lam.); aveia-preta (Avena strigosa Schreb.); e aveia-branca (A. sativa L.) cv. Fapa 2. A semeadura foi realizada entre 25/7/2005 e 5/8/2005 e entre 26 e 27/4/2006. O rendimento de matéria seca foi estimado em avaliações durante o estádio vegetativo (aos 104 dias após a semeadura em 2006) e em pleno florescimento (aos 132 e 170 dias, em 2005 e 2006, respectivamente). O valor nutritivo da forragem foi avaliado considerando os teores médios de proteína bruta (PB) e a digestibilidade in vitro da matéria orgânica (DIVMO). O sombreamento moderado reduziu em 57% o rendimento médio de forragem dos três genótipos avaliados, mas aumentou em 2,3% o teor de proteína bruta (PB) e em 5,5% a digestibilidade in vitro (DIVMO) quando as plantas estavam em florescimento pleno. Entre as espécies forrageiras avaliadas, a aveia-branca e a aveia-preta apresentam maior potencial para utilização em sistemas silvipastoris na Região Sul.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
334 Leonard St
Brooklyn, NY 11211
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.