377 research outputs found
EVALUATION OF THE EFFICACY OF ALCHORNEA CORDIFOLIA MÜLL. ARG., AGERATUM CONYZOIDES LINN AND EUPHORBIA HIRTA LINN PLANT EXTRACTS AGAINST VIRULENT ASPERGILLUS SPECIES
Antifungal activities of the aqueous and ethanolic extracts of Alchonea cordifolia Müll. Arg., Ageratum conyzoides Linn. and Euphorbia hirta Linn. plants were evaluated both in vitro and in vivo against Aspergillus fumigatus, A. niger, A terreus, A, tamarii Kita. and A. ustus; these are mostly implicated in plant and animal fungal diseases. Thin layer chromatography was used to separate and identify the plant components and confirmation of phytochemical screening. Antifungal potential of the extracts were evaluated quantitativelyin vitro using well diffusion method and in vivo by studying the survival rate of Drosophila melanogaster challenged with the test standard isolates and compared with controls. The percentage yields of aqueous extracts were greater than that of ethanolic. Both extracts showed a potentially good antifungal activity, however aqueous extract had more activity. The activities increased with increasing concentration. Maximum antifungal activity was shown by aqueous of A. conyzoides against A. niger and A. ustus with the average inhibition of 20 mm each while the least activity were extracts of A. cordifolia against A. fumigatus at the concentration of 800mg/ml with 7mm zones of inhibition. Itraconazole (positive control) at 16.667m/ml, ranged from 15±0.13mm to 20±0.13mm with MIC values from 2.630mg/ml to 6.761 mg/ml. The MIC values of extracts ranged from 50mg/ml to 794mg/ml. The phytochemical screening revealed the presence of some phytochemicals. The activities of the plant extracts against the standard organisms in vivo did not correlate well with the in vitro. 
Seasonal Patterns of Herbage Accumulation Dynamics in Marandu Palisadegrass Subjected to Intensities of Continuous Stocking Management
It is relatively well reported in the literature that pastures can have similar forage net accumulation when managed with contrasting structures. However, we hypothesized that the patterns of forage accumulation dynamics of pastures managed at different canopy heights is dependent on environmental conditions. The experimental treatments were four canopy heights (10, 20, 30, and 40 cm), allocated to experimental units according to a randomized complete block design with four replicates and evaluated throughout four contrasting environmental seasons (Summer, Autumn, Winter-Early Spring, and Late Spring). Under favourable growing conditions greater forage accumulation was observed in pastures maintained taller; on the contrary, under more stressful conditions, net forage accumulation rate reduced as canopy height increased. Such patterns of responses were related to compensations between tiller population density and tissue flows during summer and late spring and the reduced capacity of taller canopies to compensate lower population with greater growth rates during autumn and winter-early spring. Pastures subjected to intensities of continuous stocking management change their patterns of forage growth as they transitioned from favourable to more abiotic stressful conditions suggesting that warm-season perennial grasses demand seasonal adjustments in grazing heights in order to maximize herbage production
Atmosfera modificada na conservação pós-colheita de Uva 'Centennial Seedless' .
Técnicas como armazenamento refrigerado e uso de atmosfera modificada em uvas são eficientes contra a degrana e a incidência de podridões, problemas que afetam diretamente a qualidade e a conservação pós-colheita das frutas. A cultivar Centennial Seedless apresenta potencial de consumo como uva fina de mesa devido à ausência de sementes. Objetivou-se nesse trabalho verificar o efeito da aplicação de atmosfera modificada passiva, com a utilização de filmes para embalagem na conservação pós-colheita de uvas cv. Centennial Seedless. Os frutos foram colhidos no estádio de casca verde amarelado, transportados, selecionados e acondicionados em diferentes filmes para embalagem: polietileno de baixa densidade (PEBD - 10 e 20 ?m) e polipropileno (PP - 6 e 10 ?m). Frutos não embalados foram utilizados como controle. Os cachos foram armazenados em câmara fria a 1°C e 85-90% UR durante 80 dias, sendo analisados a cada 20 dias, mais três dias a 22°C simulando-se a comercialização. Foram analisados: índice de abscisão das bagas, índice de podridões, desidratação do engaço e índice de escurecimento do engaço. O delineamento experimental adotado foi o inteiramente ao acaso em fatorial 5 x 4 (5 tratamentos e 4 períodos de armazenamento). Foram utilizadas 4 repetições de 3 cachos por tratamento. Os resultados foram submetidos à análise de variância e as médias foram comparadas pelo teste da diferença mínima significativa (p<0,05). Valores baixos de abscisão de bagas (3%) foram encontrados nos frutos embalados com o filme PP durante o armazenamento. A amostra controle foi a que apresentou maiores índices de podridão em todos os períodos avaliados. A desidratação do engaço foi semelhante nos tratamentos com embalagem nos períodos de comercialização simulada. As embalagens foram eficientes contra o escurecimento do engaço. Os resultados mostraram que o filme polipropileno foi o que melhor conservou a qualidade das uvas cv. Centennial Seedless
PHYSICO-CHEMICAL COMPOSITION OF EARLY AND LATE HARVESTED IMPROVED AND LOCAL SWEET POTATO (Ipomoea batatas (L) Lam) CULTIVARS ON THE JOS PLATEAU
The physicochemical composition and the energy values of the flours of both identified improved sweet potato (Ipomoea batatas (L) Lam) cultivars: CIP4400168, Ex-Igbariam, Tanzania, TIS 8164 and TIS 87/0087 and three local varieties (Land-races) of sweet potato were investigated. The cultivars were harvested after 4 months (early harvest) and 6 months (late harvest) to determine their suitability for the formulation of sweet potato secondary products. The root of each harvestwas weighed, washed, scrubbed, chipped to 1 x 1 x 6mm dimension, dried, milled into powder, sieved through 250μm mesh size sieve to obtain sweet potato flour. The flour was proximately analysed for moisture content (MC), Protein, Lipid, Fibre, Ash, Starch, Calorific value and pH using standard methods.The late harvest differed significantly in the parameters examined. The flour had low percentage moisture content ranging between 5 and 7.04% for late and early harvests respectively, indicative of long shelf life characteristics and low chances of attack by microorganisms. The crude protein values were higher (7.04%) in the flours of the early harvest but low (0.77%) for late harvest. The lipid concentration of the cultivars was low, 0.24 and 1.67% for the flours of 4 and 6 months harvests respectively. The fibre mean values of the flours were high (3.80%) in the 6 months harvest but low (1.24%) in the 4 months harvest.The ash content of the samples ranged between 0.83 and 2.56% for the flours of 6 and 4 months harvest respectively. The mean percentage values for starch of the flours were high ranging between 79.43 and 89.76% for 4 and 6 months harvested cultivars. 
State of Knowledge in Tiller Dynamics
Persistence of sown pastures is a concern for pastoral production worldwide. Fundamentally, when a pasture does not persist the problem can be expressed in terms of inadequate new tiller production or excessive tiller death. However, the collection of data to build an understanding of sward dynamics at this level is time consuming. Tiller survival diagrams are presented for a range of temperate and tropical grass species including Lolium perenne, Lolium multiflorum, Festuca arundinacea, Festuca pratensis, Phleum pratense, Bromus willdenowii, Cynodon dactylon, Brachiaria brizantha, Panicum maximum, Chloris gayana and Paspalum notatum. It is shown that each grass has a unique perennation strategy and accordingly unique strengths and weaknesses that confer persistence or lack of persistence in different situations. There is also confusion in extension circles about the trade-off between tiller size and tiller density and how to detect a suboptimal tiller density. Grass swards respond to high herbage mass by increase of tiller size and reduction in tiller density, but reduction in tiller density is often mistaken for sward decline. A distinctionmust be made between size/density compensation and sward decline. Increased understanding of sward dynamics at this level should help in the evolution of management practices that improve persistence on a range of grassland types
Morning and Afternoon Sampling and Herbage Chemical Composition of Rotationally Stocked Elephant Grass cv. Napier
Nutrient intake by grazing animals depends on the amount of dry matter consumed and its chemical composition. Forage grasses, as with any other plants, produce assimilates during the day via photosynthesis to sustain live tissues, plant growth and organic reserves (Taiz and Zeiger 2013). In that context, herbage chemical composition may vary according to variations in the photosynthesis-respiration balance throughout the day. From dawn to dusk the balance increases and herbage dry matter content as well as concentration of soluble carbohydrates increase, the reverse happening from dusk to dawn. That could interfere with nutritive value and nutrient intake of grazing animals (Delagarde 2000), since for a given bite volume the amount of herbage and its composition could vary depending on the time of the day. That could have implications for rotationally managed pastures, indicating a potential effect of time of changing animals from one paddock to the other as a management strategy. Against that background, the objective of this experiment was to evaluate dry matter (DM) content and the concentration of soluble carbohydrates (SC), crude protein (CP), neutral (NDF) and acid (ADF) detergent fibre in herbage samples harvested during the morning and afternoon periods from rotationally stocked elephant grass cv. Napier
State of knowledge in tiller dynamics
Persistence of sown pastures is a concern for pastoral production worldwide. Fundamentally, when a pasture does not persist the problem can be expressed in terms of inadequate new tiller production or excessive tiller death. However, the collection of data to build an understanding of sward dynamics at this level is time consuming. Tiller survival diagrams are presented for a range of temperate and tropical grass species including Lolium perenne, Lolium multiflorum, Festuca arundinacea, Festuca pratensis, Phleum pratense, Bromus willdenowii, Cynodon dactylon, Brachiaria brizantha, Panicum maximum, Chloris gayana and Paspalum notatum. It is shown that each grass has a unique perennation strategy and accordingly unique strengths and weaknesses that confer persistence or lack of persistence in different situations. There is also confusion in extension circles about the trade-off between tiller size and tiller density and how to detect a suboptimal tiller density. Grass swards respond to high herbage mass by increase of tiller size and reduction in tiller density, but reduction in tiller density is often mistaken for sward decline. A distinctionmust be made between size/density compensation and sward decline. Increased understanding of sward dynamics at this level should help in the evolution of management practices that improve persistence on a range of grassland types.La persistencia de los pastos sembrados es una preocupación para la producción pastoril a nivel mundial. Fundamentalmente, cuando una pastura no persiste, el problema puede expresarse en términos de producción inadecuada de nuevos macollos o muerte excesiva de macollos. Sin embargo, la recopilación de datos para comprender la dinámica de los céspedes a este nivel requiere mucho tiempo. Se presentan diagramas de supervivencia de macollos para una variedad de especies de pastos templados y tropicales que incluyen Lolium perenne, Lolium multiflorum, Festuca arundinacea, Festuca pratensis, Phleum pratense, Bromus willdenowii, Cynodon dactylon, Brachiaria brizantha, Panicum maximum, Chloris gayana y Paspalum notatum. Se muestra que cada pasto tiene una estrategia de perennación única y, en consecuencia, fortalezas y debilidades únicas que le confieren persistencia o falta de persistencia en diferentes situaciones. También existe confusión en los círculos de extensión acerca de la compensación entre el tamaño de los retoños y la densidad de los retoños y cómo detectar una densidad de retoños subóptima. Las praderas de hierba responden a una gran masa de forraje mediante el aumento del tamaño de los macollos y la reducción de la densidad de los macollos, pero la reducción de la densidad de los macollos a menudo se confunde con la disminución del césped. Se debe hacer una distinción entre la compensación de tamaño/densidad y la disminución del césped. Una mayor comprensión de la dinámica de los pastos a este nivel debería ayudar en la evolución de las prácticas de gestión que mejoran la persistencia en una variedad de tipos de pastizales.Estación Experimental Agropecuaria PergaminoFil: Matthew, Cory. Massey University. Institute of Agriculture and Environment; Nueva ZelandiaFil: Agnusdei, Monica Graciela. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; ArgentinaFil: Assuero, Silvia G. Universidad Nacional de Mar del Plata; ArgentinaFil: Sbrissia, André F. Santa Catarina State University; BrasilFil: Scheneiter, Jorge Omar. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Pergamino; ArgentinaFil: Silva, Sila C. da. Universidade de Sao Paulo; Brasi
Herbage Accumulation and Animal Performance on Xaraes Palisade Grass Subjected to Intensities of Continuous Stocking Management
The large majority of species used in Brazil belong to the Brachiaria and Panicum genus, with marandu paladisadegrass (Brachiaria brizantha (Hochst. ex A. Rich) cv. Marandu) being the main cultivated forage grass species (Santos Filho 1996). Brachiaria brizantha cv. xaraés (xaraes palisade grass) was released as an option for diversifying forage species, and it had the advantages of fast regrowth and herbage yield, favouring larger stocking rates and animal productivity (Euclides et al. 2008; 2009).
The objective of this study was to evaluate herbage accumulation and animal performance of beef cattle steers grazing continuously stocked xaraes palisade grass managed at 15, 30 and 45 cm
- …