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La fasciolosis es una zoonosis provocada por el parásito Fasciola hepatica Linnaeus, 1758, éste para poder desarrollar su ciclo biológico, necesita de un hospedero intermediario (molusco gasterópodo, Lymnaeidae), y un hospedero definitivo (mamíferos, incluyendo al hombre). Esta enfermedad, ha causado pérdidas económicas anuales de $ 200 M en el mundo. El objetivo de la presente investigación fue identificar la prevalencia de F. hepatica en los centros de rastro bovino, determinar las pérdidas económicas, e identificar las características agroecológica en donde se desarrollan los hospederos intermediarios, en la provincia de Imbabura, Ecuador. Se identificó una prevalencia de F. hepatica, de 10,9%, donde el Cantón Otavalo presentó 190 muestras positivas (19,7%), considerándose el punto con mayor prevalencia dentro del estudio. Los bovinos positivos fueron, 102 machos (26,9%) y 277 hembras (73,1%), los cuales pertenecen al biotipo Mestizo (53,5%), Holstein (42%) y Normando (4,5 %), siendo el 78,6% mayores a dos años y 21,4% menores a dos años. Se presentó una pérdida económica anual de $ 69.547,5 dólares americanos. Los 20 biotopos muestreados, se mantuvieron dentro de los valores promedio; distancia del centro poblado 0,7 km, área de 42,8 m2; 31 moluscos por biotopo, pH del suelo 7,1; profundidad del agua 2,3 cm; altitud de 2.019 a 2.772 msnm; temperatura de 20 °C y humedad relativa de 74%. Los moluscos se ubicaron en acequias (55%), charcos (25%), pantanos (10%), riachuelos y el suelo (5%), con presencia de kikuyo (Pennisetum clandestinum Hochst. Ex Chiov, 1903) y totora (Schoenoplectus californicus C. A. Mey., 1850) como especies dominantes. La provincia de Imbabura posee una prevalencia moderada en cuanto a epidemiología por parte de fasciolosis, se confirma que estas zonas presentan un ecosistema apto para el desarrollo del ciclo biológico de la fasciolosis.

The use of organic manures, constitute an alternative to that of polluting artificial fertilizers. In this study, the effect of various levels of hen droppings fertilization on the production of biomass, chemical composition and carrying capacity of P. clandestinum were evaluated at the Research and Experimental Farm (REF) and at the Animal Nutrition and Feeding Laboratory of the University of Dschang, between April and September 2016. A completely randomized block design comparing three nitrogen level of fertilization in hen droppings form (0; 100 and 200 kg N/ha) on 4 m2 plot of P. clandestinum were used. Each treatment was carried out in four replications for a total of 12 experimental plots. Then a sample of 500 g of forage has been collected in the center of each plot, then dried and used for the evaluation of the biomass and the chemical composition of P. clandestinum, according to the level of fertilization and the cutting frequency. The results showed that the fertilization with the hen droppings positively influenced (p tion at the first cutting frequency and the highest value (47.12 cm) was obtained with of 200 kg N/ha rate of fertilization. The biomass of this fodder increased significantly (p s with the increasing cutting of frequency whatever the level of fertilization. Independently of the fertilization and the cutting frequency, the maximum biomass (6.22 t DM/ha) was obtained with the first cutting at the 200 kg N/ha of hen droppings fertilization. The fertilization influenced in variable way the chemical composition of P. clandestinum. The dry matter and organic matter content decrease with the level of fertilization and the highest values (83.79% and 89.39% respectively for the DM and OM) were obtained on the control plot at the third and the first cutting. Moreover, the ash and crude protein contents increased significantly (p

Land degradation is a global problem leading to a diminished production capacity of the rangelands. The consequence is reduced potential to provide ecosystem services and increased vulnerability to the inhabitants. Biological soil water conservation measures can reverse the trend. Different communities prefer different grass species for rehabilitation as communities vary in location, needs, priorities, preferences and the type of livestock reared. This study, therefore, sought to identify the suitable grass species for soil erosion and rehabilitation from the community in Keekonyoie ward In Narok county, Kenya. Data collection was through individual interviews, focus groups, key informant interviews and field observations. Results showed that level, indicators, causes and impacts are known to the community. Cynodon plectostachyus (76%), Chloris gayana (73%), Pennisetum clandestinum (69%), Cymbopogon citratus (46%) and Themeda triandra (42%) were most preferred for rehabilitation and soil erosion control. The primary reason for the grasses choice was a yearlong provision of livestock feed. Needs and livelihood priorities significantly influence decision-making among the Maa-speaking community in Keekonyoie ward. We recommend consideration of community needs, priorities and preferences in the selection of grass species for rehabilitation to increase the adoption measures that can reverse land degradation Key words: Indigenous knowledge, community perceptions, range grass species, rehabilitation, land degradation, Narok.

The main objective of this study was to determine the effect of irrigation using three different types of waters, namely treated wastewater through membrane bioreactor (MBR) system, treated wastewater via intermittently decanted aerated lagoon (IDAL) process and tap water (TW) on soil pH and electrical conductivity (EC) under kikuyu grass production. No fertilizer was added during the study period (1 year). Irrigation waters and water and soil samples extracted from different soil depths were analysed in laboratory. Considerable changes occurred in soil characteristics over the study period under various treatments. Soil pH increased more than 1 unit under irrigation with treated wastewater produced by the IDAL system while soil irrigated with treated wastewater from the MBR treatment system showed little change and TW irrigated soil evidenced a slight decrease when compared to pH at the beginning of the study. There was also a remarkable increase recorded for EC1:5 of top soils irrigated with treated wastewaters compared to the initial EC of the soil. The results from this study highlighted the benefits of irrigation with treated wastewater from the MBR system due to its lower cost of treatment compared to the IDAL process while providing additional nutrients such as nitrogen and phosphorus from the wastewater for plant growth.

Treated wastewater, also called as recycled water, is a reliable source of water for various non-potable purposes. One of the most common uses of recycled water has been for irrigation. A soil column study was carried out for a period of one year. The objective of this study was to determine the effect of irrigation using two different types of treated wastewaters on kikuyu grass ( Pennisetum clandestinum ) production in the absence of any kind of chemical fertilisers. Soil irrigated with secondary treated wastewater, MBR (Membrane Bioreactor), resulted in highest annual grass production (16,241 kg of dry-matter per hectare (kg DM/ha)) compared to advanced treated wastewater, IDAL (Intermittently Decanted Aerated Lagoon), and tap water (TW) with annual yields of 7028 and 14,216 kg DM/ha, respectively. Irrigation waters, soil extracted waters and soil samples from different depths of the columns were analysed. Sodium adsorption ratio (SAR), exchangeable cations, electrical conductivity (EC) and pH changed in each experimental column due to different characteristics of applied irrigation waters. The results indicate that high contents of nitrogen and phosphorous in MBR water compensated for the presence of moderate salinity level that contributed to the higher production of grass compared to other two types of irrigation waters. The increase in pH from initial amount of 5.9 to 7.3 in top part of IDAL-irrigated soil may have resulted in low grass yield. This pH increase can be attributed to the high concentrations of cations in the irrigation water in the lack of sufficient amount of nitrogen. Overall, the study demonstrated that a relatively higher grass yield in the absence of any types of fertilisers is possible with recycled water irrigation using secondary treated wastewater. Further, the recycled water irrigation with advanced treatment of wastewater, while costs more, does not result in increased yield benefits.

Two complementary experiments were conducted to investigate the relationships between the canopy structure of Pennisetum clandestinum (kikuyugrass) pastures created by intermittent stocking strategies and daily herbage intake by cattle. The first experiment (Exp. I) evaluated the relationship between different pre-grazing heights (10, 15, 20, and 25 cm) and a single defoliation intensity (50% reduction in the initial heights). In the second experiment (Exp. II), four defoliation intensities (40, 50, 60, or 70% reduction in height) were combined with a single pre-grazing height (25 cm). The following variables were analyzed: i) plant-part composition, herbage mass, and bulk density of the grazing layer; and ii) daily herbage intake. The data were analyzed using orthogonal polynomial contrasts. The Tukey-Kramer test was used to compare daily herbage intake means so that the differences among treatments could be characterized. In general, herbage intake decreased as the pre-grazing canopy height decreased (Exp. I; P = 0.03) and as defoliation intensity increased (Exp. II; P = 0.02). These response patterns were associated with canopy structure, both that existing before and that created during the stocking period. In conclusion, pre-grazing heights lower than 25 cm or defoliation intensities greater than 40% reduce daily herbage intake by cattle in kikuyugrass pastures under intermittent stocking. RESUMO Dois experimentos complementares foram conduzidos para investigar as relações entre a estrutura do dossel de pastagens de Pennisetum clandestinum (capim-quicuiu) criadas por estratégias de lotação intermitente e o consumo de forragem por bovinos. O primeiro (Exp. I) avaliou o efeito de diferentes alturas em pré-pastejo (10, 15, 20 e 25 cm) associadas com uma única severidade de desfolhação (50% das alturas iniciais). No segundo (Exp. II) quatro severidades de desfolhação (40, 50, 60 ou 70% da altura total) foram combinadas com uma única altura inicial (25 cm). As variáveis analisadas foram: i) composição morfológica, massa e densidade do estrato de pastejo; ii) consumo de forragem. Os dados foram analisados por contrastes de polinômios ortogonais. Entretanto, para uma melhor caracterização das diferenças entre tratamentos, optou-se por comparar as médias de consumo pelo teste de Tukey. De modo geral, o consumo de forragem diminuiu com a redução da altura em pré-pastejo (Exp. I; P=0,03) ou com o aumento da severidade de desfolhação (Exp. II; P=0,02), em resposta as estruturas criadas antes e durante o processo de ocupação. Ademais, houve uma aparente abdicação dos animais em compensar estas condições com ajustes no comportamento ingestivo. Concluiu-se que alturas em pré-pastejo menores que 25 cm ou severidades de desfolhação maiores que 40% reduzem o consumo de forragem por bovinos em pastos de capim-quicuiu sob lotação intermitente.

The local ecological knowledge (LEK) and perceptions of grasses were investigated in six semi-arid communal areas in the central Eastern Cape province, South Africa, and compared with field studies and scientific knowledge. Of the total of 21 grasses identified in the field survey, communal farmers had vernacular names only for 11 species. Respondents rated Digitaria eriantha and Pennisetum clandestinum to have the highest (p < 0.05) grazing value. Respondents’ ratings of Eragrostis obtusa and Sporobolus africanus as having similar (moderate) grazing values to Themeda triandra is against the established knowledge. Respondents’ ratings of T. triandra and S. africanus as having higher (p = 0.01) ecological value than the other grasses concur with the scientific knowledge, whereas their nomination of E. obtusa and D. eriantha as providing less ecological benefits than Aristida conjesta disagrees with some ecologists. The study hinted at the complementarity and discrepancies between LEK and scientific knowledge that need ratification. The respondents’ lack of detailed knowledge is suggestive of a gradual eroding of LEK among the local communities that will adversely impact the local people’s ability to implement sustainable rangeland utilisation practice. The current study also recognised farmers’ familiarity as well as training needs that would expound their knowledge and management of grasses.Keywords: communal grazing, ecological value, forage production, grazing value, semi-arid

Pasture meters are typically calibrated to estimate total pasture mass (TPM). Recent studies have shown that animal productivity was driven by the level of utilisation of the top leafy stratum (TLS) rather than the TPM. A study of kikuyu (Pennisetum clandestinum) pasture conducted on two farms located in southeast Queensland, Australia assessed whether pasture mass of the TLS, bottom stemmy stratum (BSS) and TPM can be more accurately estimated by using not only pasture surface height but also pasture density derived from height data captured by a laser sensor. The results indicated that there was a notable improvement of the pasture mass estimates when density was included in the calibration equations. The study also compared the accuracy of the pasture mass estimates between the laser sensor and mechanical pasture meters (rising plate meter and ruler). The results indicated that all devices provided reasonable estimates of pasture mass for TLS, BSS and total (R2 ≥ 0.75). However, pasture mass was estimated with a slightly higher level of accuracy when using the laser sensor in comparison with the other pasture meters, particularly for the top leafy stratum (R2 = 0.81 vs R2 ≤ 0.77).

Being the main constituents of lawns, turfgrass species have been the subject of numerous studies, particularly on their behavior. But if the literature is full of tests carried out under conditions of temperate climate, the knowledge on the behavior of these species in the particular conditions of Morocco remain very limited if nonexistent. The present work is a contribution in this direction. It aims to study the behavior of turfgrass species in order to determine species resistant to edapho-climatic conditions in the eastern Morocco. Thus, a first test was conducted to determine in the laboratory under controlled thermal conditions (25 ± 1 °C) the germination rate and kinetics of five species: Pennisetum clandestinum, Lolium perenne, Festuca arundinacea, Agrostis stolonifera and Poa pratensis. The results obtained showed that the percentage and the germination speed of differ according to the species studied. In fact, Lolium perenne showed the shortest germination time with a germination rate of 92% in 7 days. Germination peaks after 9 days for the species Festuca arundinacea and Agrostis stolonifera with a percentage of 99% and 89% respectively, and at the end of the 10th day for Pennisetum clandestinum of 80%. Poa pratens is had the lowest rate, 61% after a 30 day period. The results prouve that the measured germination velocity through the germination median duration (T50) varies between one day to five days .the species Agrostis stolonifera and Lolium perenne being the fastest to germinate (1 day) and Poa pratensis is the slowest (5 days).

El rastrojo de arroz constituido por tallos y hojas, puede ser un importante subproducto de cosecha del grano de arroz para ser utilizado en la dieta de rumiantes, en razón de su abundante disponibilidad. El aumento de las regulaciones y restricciones sobre la quema de rastrojos, ha estimulado el interés por usar para otros propósitos, incluyendo la alimentación del ganado. La técnica de degradación in situ ha sido ampliamente adoptada para evaluar la tasa de degradación de alimentos en el rumen. El objetivo del trabajo fue evaluar mediante la técnica de degradación ruminal in situ, la degradabilidad de la materia seca (MS) del rastrojo de arroz tratado con seis niveles de urea: 0, 5, 10, 20, 30 y 40 g kg MS-1. Los sustratos secos fueron fragmentados en dos tamaños de partícula: una parte picada a 2 cm y otra parte molida a 2 mm, ambos tipos de sustratos fueron incubados en horno de aire forzado a 40 °C durante 10 días. Se utilizaron ocho vacas provistas de cánula ruminal para los ensayos de digestibilidad in situ, a 48 y 96 horas de incubación en rumen. Cuatro vacas recibieron una Dieta de Alta Actividad Ruminal (AAR) ajustada a consumo de 5 kg MS día-1 de heno de alfalfa (Medicago sativa L.) + heno de una mezcla forrajera (Pennisetum clandestinum Hochst. ex Chiov, Lolium perenne L. y Dactilys glomerata L.) ad libitum + 1.8 kg de concentrado, y cuatro vacas restantes recibieron una Dieta de Baja Actividad Ruminal (BAR) basada en heno de la misma mezcla forrajera y concentrado. Los datos fueron analizados mediante regresión múltiple por pasos sucesivos. Los resultados muestran aumentos en la degradabilidad de la MS con el incremento en el nivel de urea en dietas con AAR y a 96 horas de incubación. El tamaño de partícula no afectó la respuesta animal. Se concluye que este subproducto de cosecha tratado con urea puede ser una importante fuente de fibra para rumiantes en los trópicos

The Brazilian cattle herd (>200 million) contributes, via excreta, 41% of the national emission of nitrous oxide (N2O), but little country-specific information exists on related emission factors and mitigation options. The aims of this study were: (i) to determine the N2O emission factors (EF) for dairy cattle urine and dung in a subtropical pasture and compare them with the 2% EF adopted by the IPCC; (ii) to evaluate the efficacy of the nitrification inhibitor dicyandiamide (DCD) to reduce those N2O emissions; and (iii) to determine if the best mode of DCD application is dissolved into or sprayed on urine and dung. An experiment was conducted in a kikuyu grass (Pennisetum clandestinum) pasture over a haplic Cambisol, in southern Brazil. Fresh urine and dung from Friesian dairy cows were applied with or without application of DCD; DCD was dissolved into the excreta before its application onto the soil, or was sprayed on the excreta patch. Treatments were applied four times, once per each season of 2014 (in different spots, same area). After excreta application, N2O fluxes were monitored in 10 air sampling sessions over 63–68 days, by using closed static chambers. Urine and dung were important sources of N2O, with an average EF of 0.34% for urine and 0.11% for dung; this urges the investigation of related mitigation strategies for Brazilian cattle systems. Yet, those emission factors were not as high as the IPCC default value of 2%, which suggests that this default value may need to be revised for the subtropical region. Additionally, this revision should consider the disaggregation of the EF for urine and dung. As a mitigation strategy, the use of DCD had a potential to curb N2O emission from urine patches, particularly in the cooler seasons of autumn and winter, when it reduced emissions by 60–82% after being dissolved in urine. DCD sprayed on excreta patches significantly reduced emissions in autumn only (by 47%) and thus was less efficient than when dissolved in urine. With respect to dung, there was no clear evidence that N2O emission from that excreta is mitigated by DCD, either dissolved into the dung mass or sprayed over the dung pat. ––

Knowledge about the net lactation energy (NLE) contained in the dry matter of grasses is necessary to make decisions about forage and the balance of diets for grazing cattle. Its determination is made in laboratories using wet or dry chemistry methods, which are costly, delayed, and sometimes present sampling- or process-related reliability problems. An algorithm, which analyzes the red-green-blue (RGB) images of grasses taken by drone, has been developed as a technological alternative. This has allowed us estimating the NLE level, reducing costs, and changing the sampling system and analysis method. The objective of the present study was to compare the milk production, which was calculated from the NLE and estimated using the algorithm for analysis of RGB images of grasses (included in the TaurusWebs® software), vs the actual milk production. The study was conducted in 15 dairy farms belonging to the dairy control system of the Colácteos dairy cooperative, which are located in the upper tropical region (Department of Nariño, Colombia). The prairies evaluated were composed of mixtures of Kikuyo (Pennisetum clandestinum), Raigrás (Lolium spp), and False Poa (Holcus lanatus). The result was analyzed using a linear regression model (R²=0.86; R=0.93). In the Student´s t-test, the actual and estimated milk production averages were equal (P>0.05). In conclusion, the NLE calculated using the algorithm satisfactorily explains the study livestock production, and the information generated by the algorithm can be used to calculate the NLE of grasses. RESUMO: O conhecimento sobre a energia líquida de lactação (NLE) contida na matéria seca das gramíneas é necessário para a tomada de decisões sobre forragem e o equilíbrio das dietas para pastagem. Sua determinação é feita em laboratórios usando métodos de química úmida ou seca, que são dispendiosos, atrasados e às vezes apresentam problemas de confiabilidade relacionados a amostras ou processos. Um algoritmo, que avalia as imagens vermelho-verde-azul (RGB) de gramíneas tiradas por drone, foi desenvolvido como uma alternativa tecnológica. Isso nos permitiu estimar o nível de NLE, reduzir custos e alterar o sistema de amostragem e o método de análise. O objetivo do presente estudo foi comparar a produção de leite, calculada a partir do NLE e estimada usando o algoritmo para análise de imagens RGB de gramíneas (incluídas no software TaurusWebs®) versus a produção real de leite. O estudo foi realizado em 15 fazendas leiteiras pertencentes ao sistema de controle de laticínios da cooperativa de laticínios Colácteos, localizada na região tropical superior (Departamento de Nariño, Colômbia). As pradarias avaliadas foram compostas por misturas de Kikuyo (Pennisetum clandestinum), Raigrás (Lolium spp) e False Poa (Holcus lanatus). O resultado foi analisado usando um modelo de regressão linear (R² = 0,86; R = 0,93). No teste t de Student, as médias reais e estimadas de produção de leite foram iguais (P> 0,05). Em conclusão, o NLE calculado usando o algoritmo explica satisfatoriamente a produção animal estudada, e as informações geradas pelo algoritmo podem ser usadas para calcular o NLE das gramíneas.

Soil nitrification (microbial oxidation of ammonium to nitrate) can lead to nitrogen leaching and environmental pollution. A number of plant species are able to suppress soil nitrifiers by exuding inhibitors from roots, a process called biological nitrification inhibition (BNI). However, the BNI activity of perennial grasses in the nutrient-poor soils of Australia and the effects of BNI activity on nitrifying microbes in the rhizosphere microbiome have not been well studied. Here we evaluated the BNI capacity of bermudagrass (Cynodon dactylon L.), St. Augustinegrass (Stenotaphrum secundatum (Walt.) Kuntze), saltwater couch (Sporobolus virginicus), seashore paspalum (Paspalum vaginatum Swartz.), and kikuyu grass (Pennisetum clandestinum) compared with the known positive control, koronivia grass (Brachiaria humidicola). The microbial communities were analysed by sequencing 16S rRNA genes. St. Augustinegrass and bermudagrass showed high BNI activity, about 80 to 90% of koronivia grass. All the three grasses with stronger BNI capacities suppressed the populations of Nitrospira in the rhizosphere, a bacteria genus with a nitrite-oxidizing function, but not all of the potential ammonia-oxidizing archaea. The rhizosphere of saltwater couch and seashore paspalum exerted a weak recruitment effect on the soil microbiome. Our results demonstrate that BNI activity of perennial grasses played a vital role in modulating nitrification-associated microbial populations.

A fruticultura brasileira tem grande importância na economia, aparecendo como o terceiro maior produtor mundial. Neste contexto, o manejo de plantas daninhas torna-se indispensável do ponto de vista agronômico, pois competem por água, luz, nutriente e espaço, causando muitos prejuízos às culturas de interesse. Essas perdas se acentuam à medida que não são devidamente controladas, por este motivo, é realizado o levantamento fitossociológico, que permite conhecer a dinâmica das plantas daninhas e sua correta identificação. Objetivou-se com esse trabalho efetuar um levantamento fitossociológico das plantas daninhas existentes no cultivo de frutíferas de clima temperado no município de Lavras-MG. O levantamento foi realizado no setor de Fruticultura da Universidade Federal de Lavras (UFLA). Foi realizado o levantamento fitossociológico em 18 cultivares de Pereira (Pyrus spp.), sete cultivares de Macieira (Malus domestica L.), 22 cultivares de Pessegueiro (Prunus persica (L.) Batsch), sete cultivares de Framboesa, dez cultivares de Amora-Preta (Rubus spp.), além de área plantada com 11 cultivares de Caquizeiro (Diospyrus kaki L.), uma cultivar de Figueira (Ficus carica L.) e 34 cultivares de Marmeleiro (Cydonia oblonga e Chaenomelis sinensis L.). As identificações das plantas daninhas foram baseadas através de análise do material, fotografias e com consulta à literatura especializada, posteriormente a identificação, houve a classificação e análise da estrutura da comunidade, fazendo o agrupamento em famílias, nome científico, nome vulgar e quanto ao ciclo produtivo vegetal das espécies. Foram avaliadas Distribuição Espacial, Variância, Densidade, Frequência, Constância, Dominância, Valor de Importância, Índice de Valor de Importância e Avaliação de Similaridade. O levantamento fitossociológico evidenciou que a espécie Cyperus rotundus foi a espécie com maior IVI no cultivo da amoreira, framboesa, macieira e marmeleiro. Enquanto que a espécie Cynodon dactylon teve o maior IVI no cultivo das framboesas, pereiras e marmeleiros. Por outro lado, a espécie Brachiaria plantaginea atingiu o maior IVI no cultivo das macieiras. Por fim, a espécie Pennisetum clandestinum atingiu o maior IVI no cultivo dos caquizeiros. De acordo com o levantamento fitossociológico, deve-se verificar os métodos de controle utilizados como implementos agrícolas, formas de aplicação de inseticidas (sistêmicos ou contato), o sistema de irrigação que menos contribua para o desenvolvimento das espécies indesejáveis, e assim diminuir competição pela água, luz e nutrientes com o aumento da produtividade.

This study evaluated the leaf area index (LAI) recovery mechanisms and forage accumulation rates on the regrowth of different grass species subjected to different defoliation intensities. For that purpose, plots of Pennisetum clandestinum (kikuyugrass), Lolium multiflorum (annual ryegrass), and Avena strigosa (black oats) were defoliated from 20 to 80 % of their initial heights (25, 20, and 25 cm, respectively). At different increments in height, forage samples were collected to ground level and used to estimate tiller population density (TPD), leaf area per tiller (LA), and forage mass. From these data, we calculated the leaf area index (LAI), average leaf area index (aLAI), and average and instantaneous forage accumulation rate (FAR and IFAR, respectively). Data were plotted over time (days) to describe LAI recovery and forage accumulation rates. As the defoliation intensity increased, greater canopy heights were needed for pastures to achieve their maximum forage accumulation rates, which required longer regrowth intervals. The need for high tiller recruitment after defoliation, which delayed canopy LAI recovery, seemed to be one of the main cause. Thus, grazing management strategies that involve costly tiller recruitment could decrease both overall forage production and sward persistence over time. However, the plant ability to recover LAI after successive intense defoliations seems to be species-dependent and related to their phenotypic plasticity.

This study aimed at determining the nutritional efficiency of Kikuyu grass, when it is cultivated at different altitudes and defoliated with a different number of leaves per tiller. Four farms, with Kikuyu pastures (Cenchrus clandestinus), were selected, two in an average altitude of 2,552 m.a.s.l. and two in average altitude of 2,914 m.a.s.l. In each farm, there were established eight plots of 4 m2 each (four treatments, two replicates). For 10 months, the pastures were defoliated when they presented 4, 5, 6, and 7 leaves per tiller (treatments) at 5 cm above ground when 90% of the tillers reached the number of leaves corresponding to each treatment. Data were analyzed as serial experiments using a completely randomized block (farms) design with an analysis of variance. The leaf appearance interval was higher for the highest altitude (8 vs. 10 days) but vary among treatments at a lower altitude (P

Grain-based concentrate (GBC) supplement is of high cost to dairy farmers as a feed source as opposed to grazed pasture. Milk production response to GBC is affected by the composition and nutritive value of the remainder of the diet, animal factors, and interactions between forage type and level of GBC. In grazing systems, dairy cattle encounter contrasting pasture states, primarily because the social structure of the herd affects the timing of when each animal accesses a paddock after milking as a result of a relatively consistent cow milking order. However, the effect of feed management, namely pasture state and GBC allocation, on dairy cattle production and behavior is unknown. We examined the effect of varying GBC allocation for dairy cattle grazing differing states of kikuyu grass (Pennisetum clandestinum, a tropical pasture species; experiment 1) and annual ryegrass (Lolium multiflorum L., a temperate pasture species; experiment 2) on dry matter intake, milk production and composition, and grazing behavior. For each experiment, 90 lactating dairy cattle were randomly allocated to 2 consistent (fresh-fresh and depleted-depleted) and 2 inconsistent (fresh-depleted and depleted-fresh pasture state treatments (defined as sequences of pasture state allocation for the morning and afternoon grazing events) and 3 GBC treatments [2.7, 5.4, and 8.1 kg of dry matter (DM)/cow per day], giving 12 treatment combinations for each experiment. The duration of each experiment was 14 d, with the first 7 d used as adaptation to treatment. In each experiment, 3 cattle were selected from each of the 12 pasture type × GBC treatment groups within the experimental herd to determine herbage intake and total DM digestibility using the n-alkanes method (n = 36). There was no interaction between kikuyu grass or ryegrass pasture state and GBC level for intake, digestibility, or milk yield or components. Dairy cattle offered fresh-fresh and depleted-fresh ryegrass produced 9% more milk yield, in line with greater pasture intakes, compared with fresh-depleted and depleted-depleted pasture states. Dairy cattle offered fresh-fresh kikuyu grass had 8% more milk yield and 14% more milk protein yield than other pastures states, but there was no effect of pasture state on milk composition. Milk yield increased with GBC level for both pasture species (∼0.7-0.8 kg of milk/kg of DM GBC) as GBC level increased from 2.5 to 5.4 kg of DM/cow per day. There was a poor response (0.3 kg of milk/kg of DM GBC), and no response, when GBC levels increased from 5.4 to 8.1 kg of DM/cow per day for kikuyu grass and ryegrass, respectively, in line with pasture DMD. Time spent grazing, lying, and ruminating were not associated with kikuyu grass pasture state, GBC, or their interaction. Despite this, there was a linear increase in grazing time in the afternoon coinciding with a linear decrease in lying and rumination time for both kikuyu grass and ryegrass pasture. Together these findings reveal the effect of pasture state and GBC allocation on dairy cattle production and behavior. Tailoring GBC allocation to the state of pasture accessed by cattle appears unwarranted, but there is an opportunity to alter the timing of pasture access to increase herd-level milk production efficiency.

A comprehensive life cycle assessment of the US beef value chain requires the collection of region-specific data for accurate characterization of the country’s diverse production practices. Cattle production in Hawaii is very different from the rest of the country due to its unique ecosystem and geographic location. A survey of cattle producers provided information on herd size and characteristics, grazing management, forage and feed sources, and marketing. Ranch survey responses represented 44% of the state’s beef cows with operation sizes varying from 5 to 10,000 cows. Most cows (79%) were maintained on operations that finished at least some of their cattle, and the majority of those operations finished cattle on forage without concentrate feeds. Cattle were kept on natural pastures ranging in size from 16 to 52,610 ha per ranch with a stocking rate of 2.4 ha/cow on cow-calf operations and 2.0 ha/animal on operations that included older growing animals. Common forage species were Panicum maximum (guinea or green panic grass), Pennisetum clandestinum (kikuyugrass), Digitaria eriantha (pangola or digitgrass), and Trifolium repens (white clover). Reported cow and finished cattle BW were 498 ± 52 kg and 493 ± 75 kg, respectively. More ranchers marketed their beef cattle through wholesalers or distributors (34%) rather than directly to consumers (24%), retailers (20%), or other channels (17%). Marketing under grass-fed certification was reported by 39% of ranches. Information obtained is being used to define management characteristics for modeling production systems and performing a comprehensive assessment of the sustainability of beef cattle production.

The study of the effect of added quantity of the essential oil of Callistemon viminalis on the in vivo digestibility of Pennisetum clandestinum and some biochemical parameters on the West African Dwarf goat was conducted with nine old West African Dwarf goats. After the adaptation period, each animal received 900 and 100 g/day of Pennisetum clandestinum hay and concentrate respectively, associated with 0, 100 or 200 mg essential oil/kg of DM. The samples of 100 g of each ration, faeces and 10 ml of urine were collected and analyzed for chemical composition and the evaluation of ingestion and digestibility. Also blood samples were obtained from jugular vein of all goats after in vivo digestibility test for the dosage of biochemical parameters. The results of this study show that the ingestion of dry matter, organic matter and the fibers were significantly (p < 0.05) higher on the goat with the ration FPc + HECv200. The digestibilities of these same components were equally higher with the ration FPc + HECv200 (71.00% and 69.00% respectively for the dry matter (DM) and organic matter (OM)). Retained (5.64 g/j) and digested (51.33) nitrogen were significantly (p < 0.05) higher with the ration FPc + HECv200. The values of blood metabolites studied increased significantly (p < 0.05) with added quantity of essential oil in the rations, except for albumin, globulin, glucose and the low-density lipoprotein (LDL). In general, the incorporation of essential oils of Callistemon viminalis in the ration improved ingestion, digestibility and biochemical parameters on the West African Dwarf goat.

Kikuyu grass (Pennisetum clandestinum Hochst. ex Chiov) is tropical grass originates from Eastern Africa, that has been introduced in other tropical and subtropical areas including in Indonesia. Kikuyu used as forage with high protein content and palatable. In Indonesia, Kikuyu still rarely exists, and no data reported yet about Kikuyu growing in Indonesia except data about when it was introduced to Indonesia. The aims of this study were to know the biodiversity of Kikuyu in Indonesia and to compare its morphology and nutrition contents between accession. Exploring Kikuyu accessions was done around West of Java province area. The morphology of each accession was observed with parameters and nutrition content of each accession was analyzed using proximate analysis. The results showed 3 accessions of Kikuyu from Burangrang, Tangkuban Perahu and Bukit Tunggul location. Morphology of the 3 accessions shows not significant different in all parameters. Nutrition contents between accessions namely dry matter, water contents, and fat contents shows not significant different. Crude protein content of Kikuyu accessions was ranged between 18.18 to 21.48 % DM. In this study, Burangrang accession had higher crude protein (21.48%) than other accessions, for that it has potential to be developed as superior variety.

Kikuyu (Pennisetum clandestinum Hochst. ex Chiov) is an important forage containing high crude protein for livestock. Molecular analysis of kikuyu relies on high yields of pure DNA and suitable PCR conditions. This research aimed to extract DNA from kikuyu based on weight of the sample and amplify the DNA of Burangrang accession using specific primers. 100 grams and 200 grams leaves of 3 accessions of kikuyu from Burangrang, Bukit Tunggul, and Tangkuban Perahu were extracted by Qiagen Mini Kit Plant. Concentration and purity of DNA were analyzed by NanoDrop Spectrophotometer 2000. DNA from Burangrang accession was amplified using six specific primers at different annealing temperatures. The result showed that the yield of DNA ranged 2.2 µg/µl to 21.4 µg/µl and the purity (ratio) were 1.08 to 2.01. Bukit Tunggul and Burangrang accession showed the same interaction pattern on the sample weight for concentration and purity. One hundred grams of leaves from Burangrang accession produce the highest concentration and the best purity of DNA, but no difference between other weight and accession. Reproducible amplifiable products were observed in all PCR reactions except primer K2. These results indicated that optimized protocol is suitable for further work on molecular identification of kikuyu.

Enteric CH4 emissions from ruminant livestock represent a loss of dietary energy and contribute to greenhouse gas emissions, actually, that is depending on feeding level and diet composition. We calculated emission factors of methane depending to enteric fermentation of Holstein cattle in Andean zone of Colombia, based on methodology IPCC Tier 2. This study involved animal performance, management practices for improved livestock productivity, higher digestibility of pasture and forage from silvopastoral system of the association Pennisetum clandestinum/Trifolium repens on paddocks bounded by live fences of Acacia decurrens. For that, some model parameters and Tier-2 model equations were applied: body weight, mature weight, daily gain, weight loss, milk production, milk fat content, pregnancy rates and quality of feed to calculate gross energy GE. All these variations were used to investigate the effects on predicted CH4, emission in terms of the changes in the CH4 emission factor (MEF) in kg of CH4 per head dairy cattle−1 year−1. CH4 conversion factor (MCF) as a percentage of gross energy intake with feed, resulting in emission factor of 52 kg CH4 head−1 year−1 in SPS, 28 and 45% lower than in improved pasture of Lolium multiflorum and degraded pasture of Pennisetum clandestinum in rotation with potatoes, resulting in emission factors of 72 and 93 kg CH4 head−1 year−1 respectively. These emission factors were compared with the emission factors of Tier-1 and Tier-2 methodology used value Ym default of IPCC from national inventories. Through this research these emission factors can be applied for regional and national inventories in Andean areas of Colombia with these features.

The aim of this study was to analyse lamb performance as well as conduct an economic evaluation by comparing grazing on weeds at a coffee plantation to grazing on pasturelands (Cynodon plectoslachyus and Pennisetum clandestinum) with and without supplementation. The study was carried out 40 days prior to the coffee harvest. Biological testing was conducted in the municipality of Comapa, Veracruz, using 32 male Pelibuey lambs with an average weight of 22 kg. Animals that consumed supplements and weeds at the coffee plantation had the highest daily weight gain (112.75 g). Analysis of the coffee farm considering the three existing groups (without sheep, with sheep without supplements and with sheep with supplements) presented a positive return rate, with the coffee-sheep-supplement being the best option in terms of economic, agricultural and environmental benefits as a whole, although the return rate was lower. It is concluded that the productive response of sheep obtained with a small amount of supplements (70 g/animal/day) while feeding on weeds was superior to that of animals grazing in pastures of established grasses, even when they received the same dose of supplements. Therefore it is suggested that keeping herds of sheep grazing on weeds in coffee plantations is economically profitable as well as agronomically and environmentally beneficial.

Kikuyu grass (Pennisetum clandestinum) is a perennial plant that belongs to the Poaceae family. In Argentina, it is used in warm areas as tropical pasture, forage and grass in gardens and sports fields. Species of Pythium have a cosmopolitan distribution and are important pathogens of a wide range of plant hosts. In the spring of 2009, a new disease affected areas cultivated with kikuyu grass in different parks located near the city of Buenos Aires. The symptoms were an evident chlorosis of leaves, which got circular as the affected area expanded, followed by severely rotten roots and blighting. The aim of this study was to identify the causal agent of kikuyu yellows in Argentina. An oomycete was consistently isolated from diseased tissues. The pathogen was identified as Pythium graminicola based on cultural characteristics and the morphology of vegetative and reproductive structures. Phylogenetic analyses were performed based on combined sequence datasets of the internal transcribed spacer of the nuclear rDNA and the beta tubulin gene. Pathogenicity tests were carried out and Koch’s postulates were fulfilled. This is the first report of P. graminicola causing kikuyu yellows in Argentina and in the world.

El presente estudio se realizó en un Andisol clasificado como Vitric haplustands, ubicado en el Corregimiento de Obonuco, Municipio de Pasto (Colombia). Se evaluaron algunas características químicas, en siete tipos de uso y manejo del suelo: T1: monocultivo de papa (Solanum tubersum L.), T2: pradera (Pennisetum clandestinum Hochst. ex Chiov), T3: barrera multiestrato, T4: sistema acacia - aliso, T5: banco de proteína, T6: bosque plantado (Eucaliptus globulus Labill) y T7: bosque nativo. El efecto de los tipos de uso y manejo, sobre las propiedades químicas del suelo, se evaluaron a través de pH, %MO, %CO, N total, P, CIC, Ca, Mg, K, Al, Fe, Mn Cu, Zn, B y S. Los resultados fueron sometidos a Análisis de Varianza, Prueba de Comparaciones de Medias (LSD), Diferencia Mínima Significativa (DMS) y correlaciones de Persson. Los valores mostraron diferencias significativas (P

The key to better nutrient efficiency is to simultaneously improve uptake and decrease losses. This study sought to achieve this balance using sorbent additions and manure nutrients (spent poultry litter; SL) compared with results obtained using conventional sources (Conv; urea nitrogen, N; and phosphate–phosphorus; P). Two experiments were conducted. Firstly, a phosphorus pot trial involving two soils (sandy and clay) based on a factorial design (Digitaria eriantha/Pennisetum clandestinum). Subsequently, a factorial N and P field trial was conducted on the clay soil (D. eriantha/Lolium rigidum). In the pot trial, sorbent additions (26.2 g of hydrotalcite [HT] g P− 1) to the Conv treatment deferred P availability (both soils) as did SL in the sandy soil. In this soil, P delivery by the Conv treatments declined rapidly, and began to fall behind the HT and SL treatments. Addition of HT increased post-trial Colwell P. In the field trial low HT-rates (3.75 and 7.5 g of HT g P− 1) plus bentonite, allowed dry matter production and nutrient uptake to match that of Conv treatments, and increased residual mineral-N. The SL treatments performed similarly to (or better than) Conv treatments regarding nutrient uptake. With successive application, HT forms may provide better supply profiles than Conv treatments. Our findings, combined with previous studies, suggest it is possible to use manures and ion-exchangers to match conventional N and P source productivity with lower risk of nutrient losses.

Introduction: The sustainable production of pastures has become a fundamental challenge for the livestock sector where research with plant growth-promoting rhizobacteria as a viable solution, has nearly not been reported. Objective: In this study, we aimed to examine the potential to stimulate growth in Pennisetum clandestinum grass using four isolated bacterial strains from soils obtained from a Colombian tropical silvopastoral system. Methods: We previously identified genetically the strains and characterized two plant growth promoting activities. In addition, we evaluated the growth-promoting effect of the strains in Kikuyo grass under greenhouse conditions. Results: We found that the four bacterial strains were phylogenetically associated with Klebsiella sp. (strains 28P and 35P), Beijerinka sp. (37L) and Achromobacter xylosoxidans (E37), based on partial 16S rRNA gene sequencing. Moreover, the in vitro biochemical assays demonstrated that the strains exhibited some plant growth promoting mechanisms such as 1-aminocyclopropane-1-carboxylic acid deaminase activity and indole compound synthesis. Notably, bacterial inoculation under greenhouse conditions showed a positive influence on P. clandestinum growth. We found a significant (P < 0.05) effect on root and shoot length and shoot dry weight. Shoot length increased by 52 % and 30 % with 37L and 35P compared to those without inoculation treatment. Similarly, the use of 37L and 28P raised shoot dry weight values by 170 % and 131 %, respectively. In root development, inoculation with strains 37L and E37 increased root length by 134 % and 100 %, respectively. Conclusion: Beijerinckia sp. 37L was the most effective of the four strains at increasing P. clandestinum biomass and length. RESUMEN Introducción: La producción sostenible de pastos se ha convertido en un desafío fundamental para el sector ganadero, donde investigaciones con bacterias promotoras de crecimiento vegetal, como una solución viable, han sido poco reportadas. Objetivo: El objetivo de este estudio fue examinar el potencial para estimular el crecimiento del pasto Pennisetum clandestinum utilizando cuatro cepas bacterianas aisladas de suelos obtenidos de un sistema silvopastoril tropical colombiano. Métodos: Anteriormente identificamos genéticamente las cepas y caracterizamos dos actividades que promueven el crecimiento de las plantas. Además, evaluamos el efecto promotor del crecimiento de las cepas en el pasto Kikuyo en condiciones de invernadero. Resultados: Encontramos que las cuatro cepas bacterianas se asociaron filogenéticamente con Klebsiella sp. (cepas 28P y 35P), Beijerinka sp. (37L) y Achromobacter xylosoxidans (E37), basados en la secuenciación parcial del gen 16S rRNA. Además, los ensayos bioquímicos in vitro demostraron que las cepas exhibían algunos mecanismos que promueven el crecimiento de las plantas tales como la actividad de la enzima desaminasa del ácido 1-aminociclopropano-1- carboxílico, y la síntesis del compuesto indol. En particular, la inoculación bacteriana bajo condiciones de invernadero mostró una influencia positiva en el crecimiento de P. clandestinum. Encontramos un efecto significativo (P < 0.05) en la longitud de la raíz y el tallo, y el peso seco del tallo. La longitud del tallo aumentó en un 52 % y 30 % con 37L y 35P, respectivamente, en comparación con aquellos sin tratamiento de inoculación. Igualmente, el uso de las cepas 37L y 28P aumentó los valores de peso seco del tallo en un 170 y un 131 %, respectivamente. En el desarrollo de la raíz, la inoculación con las cepas 37L y E37 aumentó la longitud de la raíz en 134 y 100 %, respectivamente. Conclusión: Beijerinckia sp. 37L fue la más efectiva de las cuatro cepas al aumentar la biomasa y la longitud de P. clandestinum.

The diversity of the riparian vegetation of five high Andean lagoons of the Junin region was evaluated between March and December of 2017. The sampling of the riparian vegetation was carried out by means of the transect method. The unidentified species were collected for later identification in the herbarium. The diversity was determined by floristic composition, abundance and frequency, and by species richness indices of Simpson and Shannon-Wiener. In the Pomacocha Lagoon, the floristic composition was represented by 43 species, distributed in 15 families, with the most abundant species being Aciachne pulvinata, Azorella crenata and Geranium sessiliflorum and the most frequent Aciachne pulvinata. In the Laguna Tragadero, the floristic composition was represented by 17 species, distributed in 10 families, with the most abundant species being Pennisetum clandestinum and Eleocharis sp and the most frequent Polypogon interruptus. In the Cucancocha Lagoon, the floristic composition was represented by 19 species, distributed in 7 families, with the most abundant species being Calamagrostis sp and Wernberia humbellata and the one of most frequent Carex ecuadorica. In the Incacocha Lagoon, the floristic composition was represented by 22 species, distributed in 11 families, with the most abundant and frequent species being Alchemilla pinnata. In the Ñahuinpuquio Lagoon, the floristic composition was represented by 20 species, distributed in 9 families, with the most abundant species being Pennisetum clandestinum and the most frequent species Pennisetum clandestinum, Juncus arcticus and Muhlenbergia andina. The results obtained contribute data on the diversity of riparian vegetation of high Andean wetlands in the Junin region, Peru. Resumo Avaliou-se a diversidade da vegetação ripária de cinco lagos altos andinos da região de Junin entre março e dezembro de 2017. A amostragem da vegetação ripária foi realizada por meio do método de transectos. As espécies não identificadas foram coletadas para posterior identificação no herbário. A diversidade foi determinada pela composição florística, abundância e frequência e pelos índices de riqueza de espécies, Simpson e Shannon-Wiener. Na lagoa Pomacocha a composição florística foi representada por 43 espécies, distribuídas em 15 famílias, as espécies mais abundantes foram Aciachne pulvinata, Azorella crenata e Geranium sessiliflorum e a mais frequente Aciachne pulvinata. Na lagoa Tragadero a composição florística foi representada por 17 espécies, distribuídas em 10 famílias, as espécies mais abundantes foram Pennisetum clandestinum e Eleocharis sp e a mais frequente Polypogon interruptus. Na lagoa Cucancocha a composição florística foi representada por 19 espécies, distribuídos em 7 famílias, as espécies mais abundantes foram Calamagrostis sp e Wernberia humbellata e a mais frequente Carex ecuadorica. Na lagoa Incacocha a composição florística foi representada por 22 espécies, distribuídas em 11 famílias, sendo a espécie mais abundante e freqüente Alchemilla pinnata. Na lagoa Ñahuinpuquio a composição florística foi representada por 20 espécies em 9 famílias, sendo a espécie mais abundante Pennisetum clandestinum e as espécies mais freqüentes Pennisetum clandestinum, Juncus articus e Muhlenbergia andina. Os resultados obtidos contribuem com dados sobre a diversidade da vegetação ripária das áreas úmidas andinas da região de Junin, no Peru.

Kikuyugrass (Pennisetum clandestinum) is a warm-season grass and invasive weed in the landscape, but can be used for golf course fairways in southern California. In 1999, a decline of kikuyugrass was observed on golf courses in southern California beginning in late summer or early autumn. Symptoms included sunken, bleached patches of turf with individual plants having chlorotic foliage and reduced vigor. Roots and stolons were often covered with dark, ectotrophic fungi, and lobed hyphopodia were visible on the stolons. On colonized roots, the cortex was rotted, and the stele showed evidence of colonization by the fungus. In March 2002, a sample of kikuyugrass exhibiting decline symptoms was obtained from a golf course fairway in Los Angeles, CA. Sections of roots and stolons were surface sterilized for 60 s in a 0.3% sodium hypochlorite solution and placed on acidified water agar. Emerging colonies were transferred to potato dextrose agar (PDA). Isolates were characteristic of Gaeumannomyces spp. (2) with dark hyphae and curled colony edges. The rDNA internal transcribed spacer (ITS) regions of two isolates (HCC-5 and -6) were amplified by polymerase chain reaction (PCR) using universal fungal rDNA primers ITS 4 (5′-TCCTCCGCTTATTGATATGC-3′) and ITS 5 (5′-GGAAGTAAAAGTCG TAACAAGG-3′) (3). PCR products were sequenced and exhibited 99% sequence identity to G. graminis var. graminis (GenBank Accession No. 87685). These isolates were grown separately on autoclaved sand and cornmeal media (1) for 21 days at 25°C. Styrofoam cups were partially filled with autoclaved medium-coarse sand, and 10 g of inoculum was spread evenly in a layer on top. This layer was covered by an additional centimeter of autoclaved sand and 5 g of kikuyugrass seed (cv. ‘AZ-1’). Both isolates were tested separately using six replicate cups per isolate. Controls were prepared using only a 10 g layer of autoclaved sand and cornmeal. Cups were misted at 1 h intervals on a greenhouse bench maintained at 25°C. Seeds germinated and emerged after ≈10 days. In cups inoculated with isolate HCC-5 or -6, dark mycelia were evident on the coleoptiles of the emerging plants. Plants were removed and washed 21 days after planting. Inoculated plants were chlorotic and had reduced root and foliar growth compared to the controls. Coleoptiles, hypocotyls, and roots were covered with dark, ectotrophic fungi with lobed hyphopodia present on the hypocotyls. In colonized roots, cortical tissue was rotted with extensive colonization of the epidermis and penetration of the fungus into the root cortex. Sections of infected root tissue were surface disinfested, placed on acidified water agar, and the resulting colonies transferred to PDA. Isolates exhibited the same colony morphology and characteristics as those previously identified as G. graminis var. graminis. To our knowledge, this is the first report of this fungus as a pathogen of kikuyugrass. References: (1) M. J. C. Asher. Ann. Appl. Biol. 70:215, 1972. (2) P. C. Cunningham. Isolation and culture. Pages 103–123 in: Biology and Control of Take All. M. J. C. Asher and P. J. Shipton, eds. Academic Press, London, 1981. (3) T. J. White et al. Amplification and direct sequencing of fungal ribosomal RNA genes for phylogenetics. Pages 315–322 in: PCR Protocols: A Guide to Methods and Applications. M. A. Innis et al. eds. Academic Press, San Diego, CA, 1990.

Kikuyugrass (Pennisetum clandestinum) is a warm-season turfgrass that has been adopted for use in fairways and roughs in a number of subtropical areas including southern California, Mexico, Australia, and South Africa. During August 2003, a foliar disease of Kikuyugrass was reported from a number of golf courses in southern California. Examination of diseased plants showed the presence of dark, olive green-to-brown lesions on the foliage. Incubation of these plants in a moist chamber for 12 h led to the production of numerous pyriform conidia from these lesions that were characteristic of Pyricularia grisea. Single-spore isolates of the fungus were obtained from infected kikuyugrass samples by transferring conidia to acidified 1.5% water agar and then transferring single, germinated conidia to one-quarter-strength potato dextrose agar. Colony morphology and conidia production were consistent with that described for P. grisea (1). Koch's postulates were performed separately for two single-spore isolates (OSGC-1 and CCCC-1) obtained from infected kikuyugrass. For each isolate, 2-week-old, glasshouse-grown seedlings of kikuyugrass (cv. ‘AZ-1’) and perennial ryegrass (Lolium perenne) grown in 75-mm pots in soilless media were inoculated with conidia from either OSGC-1 or CCCC-1. For each test, six pots of both kikuyugrass and ryegrass were inoculated, and the tests were conducted three times for each isolate. Conidia were obtained from isolates grown on clarified V8 agar in 100-mm petri plates for 14 days at 25°C. Suspensions were made by adding 10 ml of sterile distilled H2O (sdH2O) to the plates, scraping the surface of the media to dislodge the conidia, filtering the suspension through cheesecloth, and then adjusting the final concentration to 1 × 106 conidia/ml with sdH2O. Seedlings were inoculated with the conidial suspensions with an aerosol applicator, placed in plastic boxes lined with wet paper towels, and sealed to provide adequate moisture for infection. Boxes were incubated at 28°C for 48 h after which time the covers were removed and the plants maintained in ambient glasshouse conditions at approximately 28°C. In all three replicated experiments, kikuyugrass seedlings inoculated with OSGC-1 or CCCC-1 developed symptoms of disease approximately 5 days after inoculation, while inoculated perennial ryegrass did not, even 14 days after inoculation. Symptomatic kikuyugrass leaves were taken randomly from plants from each of the three replicated tests, surface disinfested in 0.3% sodium hypochlorite for 30 s, rinsed with sdH2O, blotted dry, and placed onto acidified water agar in petri plates. Twenty-four hours later, abundant sporulation was observed from symptomatic tissue with conidiophores bearing conidia typical of P. grisea. To our knowledge, this is the first report of gray leaf spot being caused by P. grisea on Pennisetum clandestinum in North America. Reference: (1) M. B. Ellis. Dematiaceous Hyphomycetes. Commonwealth Mycological Institute, Kew, Surrey, UK, 1971.

Kikuyugrass (Pennisetum clandestinum) is a C4 grass and invasive weed adopted for use as a primary turf species in some golf course fairways and roughs in southern California. In September 2008, a new Rhizoctonia-like fungus was isolated from a diseased kikuyugrass sample received from a golf course fairway in Oceanside, CA. The kikuyugrass was from a mature stand (>20 years old) that was maintained at a height of approximately 1.25 cm. Symptoms on kikyuygrass developed initially as irregular, blighted, chlorotic patches, several centimeters to one meter, which occurred during a period of warm, humid weather (27 to 29°C maximum daytime temperature, 75 to 85% average relative humidity) on a small part of one fairway. Affected areas became brown and necrotic as the disease progressed. Leaf chlorosis and stem rot were observed on affected plants. The organism was isolated by placing symptomatic leaves on acidified one-quarter-strength potato dextrose agar (PDA) (600 μl of 85% lactic acid per liter of medium) in a petri dish (1). A colony of a Rhizoctonia-like fungus with yellow aerial hyphae, multinucleate hyphal cells, and irregularly shaped, golden brown sclerotia (4 to 7 mm) developed within 30 days at 28°C. The rDNA internal transcribed spacer (ITS) sequence was obtained (GenBank Accession No. HQ850254) using PCR amplification with primers ITS1F and ITS4 (1,2), and a BLAST search showed 100% similarity with Waitea circinata var. prodigus (GenBank Accession No. HM597145), which had recently been described as the cause of basal leaf blight of seashore paspalum (Paspalum vaginatum), another C4 grass (3), in Florida. Colony morphology and other physical characteristics were similar but not completely identical to those from Florida, reflecting the reported morphological variation inherent in the pathogen (3). Koch's postulates were performed by growing this isolate on PDA in a petri dish for 7 days, homogenizing the culture with 100 ml of sterilized water, filtering the suspension through two layers of cheesecloth, and pipetting 10 ml of the mycelial suspension onto the foliage and stems of 4-week-old AZ-1 kikuyugrass plants grown in UC-soilless-mix in 7.5-cm-diameter pots (4). Control plants were treated with a homogenized and filtered dish of PDA only. There were three replicate pots for inoculated and noninoculated treatments and the experiment was repeated independently three times. All of the pots were incubated in a moist chamber with a 12-h light period at 28°C. Yellow lesions were observed on leaves and stems of inoculated plants 4 days postinoculation and necrosis developed 8 days later in all experiments. The same organism was isolated from symptomatic plants. The control plants did not exhibit any symptoms. To our knowledge, this is the first report of basal leaf blight caused by W. circinata var. prodigus on kikuyugrass in California and the first report of this pathogen affecting turfgrass in the western United States. References: (1) C. M. Chen et al. Plant Dis. 93:906, 2009 (2) K. de la Cerda et al. Plant Dis. 91:791, 2007. (3) S. J. Kammerer et al. Plant Dis. 95:515, 2011. (4) T. Toda et al. J. Gen. Plant Pathol. 73:379, 2007.

The aim of this trial was to determine the effect of ruminal fluid adapted to crude glycerol supplementation on in vitro methane and fermentation parameters of the forage Pennisetum clandestinum Hochst. Ex Chiov (Kikuyu forage) of 35 (D35) and 45 days (D45) of regrowth. Four non-lactating cannulated Holstein cows with 600 ± 33 kg LW, under a randomized Latin square design (4 animals × 4 periods), were used to obtain ruminal fluid after adaptation for 13 days within each period to supplementation in the rumen with crude glycerol (GL): 0 (GL0), 500 (GL1), 1000 (GL2), and 1500 g/cow/day (GL3). All the variables were analyzed under a 4 × 2 split-plot arrangement, where the ruminal fluid adaptation to supplementation with GL and its interaction with the incubated diets (GL× D) were analyzed. Ruminal pH values and in vitro apparent degradability of the dry matter (DMd) and organic matter (OMd) were not affected, with a decrease in the concentrations of NH3-N and acetate by the ruminal fluid adapted to crude glycerol. The concentrations of propionate and butyrate increased, without affecting the total concentration of VFA in the ruminal fluid. The in vitro methane production increased with forage D35 and GL1, GL2, GL3. The in vitro methane production with the D45 forage increased with the ruminal fluid adapted to GL2 and GL3. The ruminal fluid adapted to crude glycerol supplementation increased in vitro methane production when incubating the forage Kikuyu.

1 recurso en línea (páginas 52-62)., The Colombian Andean region, in the department of Boyacá at 2,560 meters above sea level in the Colombian dairy belt, livestock farms are characterized by the predominant perennial forage species known as Kikuyo (Pennisetum clandestinum Hochst.ex Chiov), a stoloniferous growth grass. The objective of this study was to obtain the linear regression equation for the proper calibration of the forage dish in order to predict the availability of dry matter per hectare. This investigation was carried out in the course of 2014, (from March to December); for this investigation, measurements were taken with a Forage Plate in 21 cattle farms belonging to the Alto Chicamocha region. A total of four hundred (400) samples were taken during the dry and rainy seasons. The formula was developed by means of a mathematical method of simple linear regression, relating the compressed height of the forage and the actual availability of dry matter obtained by cutting and ubsequent drying. %. According to the formula it was determined that for each unit of measurement of the forage dish, the total phytomass availability was increased in 259.42 kg of Dry Matter (MS) and an intercept of 2978.92 was obtained. These results lead to the use of the equation as an alternative to calculate dry matter available throughout the year in Kikuyo grasslands. The resulting equation for the calibration of the Forage Plate in Kikuyo grasslands (Pennisetum clandestinum) was Kg Ms / Ha = 259.42x + 2978.9 where the height compressed by the forage dish was replaced and with a coefficient of determination (R2) of 77.67%., La región andina colombiana, en el departamento de Boyacá a 2560 msnm en el cordón lechero colombiano, las explotaciones ganaderas se caracterizan por tener la especie forrajera perenne predominante conocida como Kikuyo (Pennisetum clandestinum Hochst.ex Chiov), gramínea de crecimiento estolonífero. El objetivo de este estudio, fue obtener la ecuación de regresión lineal para la adecuada calibración del plato forrajero con el fin de predecir la disponibilidad de materia seca por hectárea. Esta investigación se realizó en el trascurso del año 2014, (desde marzo hasta diciembre); para esta investigación se realizaron mediciones con un Plato Forrajero en 21 predios ganaderos pertenecientes a la región del Alto Chicamocha. Se tomaron un total de cuatrocientas (400) muestras en época seca y de lluvias. Se procedió a desarrollar la formula por medio de un método matemático de regresión lineal simple, relacionando la altura comprimida del forraje y la disponibilidad real de materia seca obtenida mediante corte y posterior secado. %. De acuerdo a la formula se determinó que, por cada unidad de medida del plato forrajero, la disponibilidad de fitomasa total se incrementó en 259.42 kg de Materia Seca (MS) y se obtuvo un intercepto de 2978.92. Estos resultados conllevan al uso de la ecuación como una alternativa de cálculo de la materia seca disponible durante todo el año en praderas de Kikuyo. La ecuación resultante para la calibración del Plato Forrajero en praderas de Kikuyo (Pennisetum clandestinum) fue Kg Ms/Ha = 259.42x + 2978.9 donde se reemplazó la altura comprimida por el plato forrajero y con un coeficiente de determinación (R2) de 77.67 %., Bibliografía: página 62.

Some recent papers have recommended moderate intensities of defoliation in order to maximize herbage intake at different time-scales. Most of them, however, did not assess the grazing dynamics of individual tillers during the stocking period. Therefore, the objective of this work was to describe the defoliation dynamics of kikuyugrass (Pennisetum clandestinum Hochst ex. Chiov) pastures subjected to different intensities of defoliation (40, 50, 60, and 70% of the initial height). Twelve 1500 m2 plots were strip-grazed over 24 h, and the frequency and severity of defoliation of individual tillers were assessed in 40 tagged tillers per experimental unit. From these data (n = 1920), we calculated the grazed area in the upper, second, and third horizon, and the total grazed area. We found that the frequency of defoliation by leaf category (expanding, mature, and senescent) increased linearly with the intensity of defoliation, and that reductions in extended tillers could not be used as a proxy to estimate the frequency of defoliation. Moreover, 22% of the second and third horizons were already exploited with intensities of defoliation of 40%, raising the possibility that the exploitation of lower grazing horizons could be more related to stocking density and relatively independent of the grazed area.

Phytophagous mites were first identified as a problem in warm-season turfgrasses in Australia around 80 years ago. In production turfgrass fields, slower growth and weakening of sod strength by mites can cause serious commercial losses through breakage of harvested rolls. Elsewhere, mite infestation is associated with poor wear resistance coupled with very slow recovery of turf on playing fields, thereby reducing the usage that is possible on such fields. At the same time, knowledge about turfgrass mites is lacking: specifically, which mite group/species is/are causing damage and to which turfgrass species. There has long been an underlying assumption, based mainly on overseas literature, that mites of the family Eriophyidae are the main cause of the distorted growth symptoms frequently seen and attributed to mite damage. During the 2010/11 growing season, an Australia-wide survey was conducted, sampling seven warm-season turfgrass genera to determine the mites present in each case. This paper reports the results of that survey, together with data from more recent mite infestations sampled during the subsequent threeyear period. Based on their frequency of occurrence, tenuipalpid mites from the genus Dolichotetranychus appear to be at least as important as eriophyoid mites on Cynodon spp.; Dolichotetranychus mites were also recorded from two survey samples of Zoysia spp. but not in subsequent sampling. Eriophyoid mites of the genus Aceria were found on Cynodon spp., with possibly a second species on Zoysia species. A number of mixed tenuipalpid/eriophyoid populations have also been found on Cynodon species. A Steneotarsonemus species (Tarsonemidae) was found associated with Pennisetum clandestinum. Grass-webbing tetranychid mites (Oligonychus spp.) also occasionally affect a wide range of warm-season turf and other grasses non-selectively.

Soil quality of tillage systems receives much attention worldwide, although few studies attempt to link soil quality to yield. Partial least-squares regression analysis is a suitable method to construct predictive models around plural, highly collinear factors, such as soil quality and its effects on yield. This study aimed at identifying the soil quality properties which best model pasture herbage yield by relating soil quality indicators with variations in yield as a result of soil disturbance caused by tillage. The study was conducted on kikuyu (Pennisetum clandestinum) over-sown with annual ryegrass (Lolium multiflorum) using different tillage methods. Tillage methods involved over-sowing kikuyu with ryegrass using a minimum-tillage seed drill, eradication of kikuyu with herbicide and ryegrass sown with a minimum-tillage planter, shallow and deep disturbance, and a control. Most changes in soil quality indicators as a result of soil tillage were observed shortly after tillage and occurred mostly at the 0–100 mm soil layer. Few of these effects were still visible 420 d after tillage. Microbiological indicators changed most in response to the treatments, but unlike the chemical and physical indicators, microbiological indicators have no causal link to pasture production. The contribution of individual soil quality indicators to variance in pasture productivity could not be isolated and should thus be seen as complex processes which affect yield. Although mechanisms of how some soil quality indicators affect yield is clear, more research is required to determine mechanisms of how a combination of multiple soil quality indicators affects yield.

This research focused on the greenhouse gas (GHG) emissions and potential sinks associated with conventional and sustainable fruit production systems in the Highlands region of Pasto, Narino, Colombia. Based on the IPCC (2006) methodologies, the annual emission balance for a 6-year production cycle included agricultural sources and gasoline consumption related to the main agricultural activities and the potential for soil C accumulation and biomass C fixation in all of the studied systems. The multivariate analysis showed that positive GHG balance emissions would be achieved in all sustainable fruit production systems, as compared to conventional fruit production systems with greater impact on (SS1): Rubus glaucus Benth. Associated with Acacia decurrens trees and live coverage of kikuyu Pennisetum clandestinum grass. According to the results of this study, (SS1) showed the beneficial total GHG balance emission accounting for -21,079 kg of atmospheric CO 2 eq ha -1 yr -1 divided into -4,587 kg CO 2 eq ha -1 yr -1 and -17,102 kg CO 2 eq ha -1 yr -1 due an annual soil and biomass C sequestration potential that could help offset its emissions (610 kg CO 2 eq ha -1 yr -1 ).

In Colombia at 2,560 m.a.s.l. the effect of three defoliation frequencies (3, 4.5 and 6 leaves tiller-1) was evaluated, during four months (August - November), on growth and nutritional quality of Kikuyu (Pennisetum clandestinum Hochst.ex Chiov). Nine plots of 6 x 4 m were established, which were distributed in a complete randomized block repeated measures design. Data were subjected to analysis of variance. A significant interaction between defoliation frequency and the month of utilization on total herbage mass yield and crude protein concentration was observed. The highest values for both variables were obtained at 6 leaves tiller-1 in October (herbage mass) and OctoberNovember (crude protein). Defoliation frequency did not modify yield components (proportion of blades, sheath, stems and dead material). Neutral Detergent Fiber and Acid Detergent Fiber were not affected by defoliation frequency. In conclusion, grazing of kikuyu swards, under similar environmental conditions of this study should be performed at stage of 4.5 to 6 leaves tiller-1 with a residual sward height of 5 cm.

El presente trabajo estuvo orientado a evaluar la precisión del algoritmo de análisis de imágenes Red, Green, Blue (RGB), incluido en el software TaurusWebs ®, que permite calcular el porcentaje de proteína cruda de la materia seca (%PC) de las gramíneas a partir de imágenes de las praderas tomadas por un dron acoplado con cámaras RGB. Se compararon las mediciones del %PC calculadas por el algoritmo frente a un referente, Near Infrared Reflectance Spectroscopy (NIRS), del laboratorio de Corpoica (Agrosavia), calibrado para gramíneas. Se tomaron 42 muestras para NIRS, 18 de gramíneas de trópico alto en Cundinamarca: kikuyo, Pennisetum clandestinum; falsa poa, Holcus lanatus; pasto brasilero, Phalaris arundinacea y 24 de trópico bajo en Tolima, Colombia: pangola, Digitaria decumbens; pará, Brachiaria mutica; bermuda, Cynodon dactylon y colosuana, Bothriochloa pertusa. Los resultados del NIRS se compararon contra las evaluaciones hechas con el algoritmo de las imágenes de las gramíneas provenientes del mismo potrero donde se tomaron las muestras. Los resultados fueron comparados usando las pruebas no paramétricas de correlación de Kendall, rho=0.83 y de Kruskal Wallis. No se encontraron diferencias entre el resultado del %PC de las gramíneas medida por NIRS vs el %PC medida por el algoritmo de análisis de imágenes RGB. En conclusión, la información generada con el algoritmo se puede utilizar para trabajos de análisis del %PC en gramíneas.

The turnover of soil organic carbon (SOC) under different land uses plays an important role in terrestrial carbon (C) cycling. However, the effects of warming on C decomposition dynamics have not been resolved due to seemingly inconsistent results among different experiments. Hence, the objective of this work was to assess soil aggregate-associated C and temperature sensitivity of SOC decomposition within bulk soils and aggregates under two contrasting land management systems in subtropical southern Queensland.We examined the temperature sensitivity of SOC decomposition (Q) and activation energy required for soil C mineralization (Ea) from bulk soils (

Water allocation is a principal planning method for managing water supplies to agricultural and horticultural land in drying climates. Regulatory bodies often establish the water allocation amount, but its distribution during the irrigation season is left to the land manager’s discretion. We evaluated approaches to best manage water allocations to a warm-season turfgrass [Pennisetum clandestinum (Holst. Ex Chiov)] grown on a free-draining sand prone to surface (0–25 mm) soil water repellence in a Mediterranean climate in south-western Australia under ‘deficit irrigation’, in a two-year field study. The three factorial experiment consisted of three levels for each treatment applied to plots (10 m2) of kikuyugrass: water allocation (5000, 6250 or 7500 kL ha−1 yr−1), irrigation schedule, and soil wetting agent rate (nil, recommended ‘label’ rate, double recommended ‘label’ rate), and was replicated three times. The irrigation schedules were based on historical net evaporation at the site, and then refined monthly using in-season net evaporation data or measurements of soil water content. Kikuyugrass growth and color was adequate when irrigated using the current regional water allocation (7500 kL ha−1 yr−1) under a low wear situation and to a lesser extent when the water allocation was lowered to 6250 kL ha−1 yr−1. Application of a soil wetting agent diminished water repellence and improved kikuyugrass color for 7500 or 6250 kL ha−1 yr−1 water allocations. Distributing a water allocation based on historical monthly net evaporation rates was a simple and effective scheduling approach to maintaining a warm-season turfgrass.

This study investigated the type and quality of forages used in smallholder farms dairy in three agro-ecological zones (Mayaga and peripheral Bugesera, Eastern Savanna and Central Bugesera, and Eastern plateau) of the Eastern Province of Rwanda in the four seasons of the year. Representative farms were randomly selected from the beneficiaries of Girinka programme. Daily feed types and quantities were recorded and samples were taken for proximate analysis. The analysis of variance (ANOVA) was used to assess the differences in use and quality between zones and seasons. Twenty-two (22) types of feeds were identified across the three zones and four seasons. Roadside grasses, Napier grass ( Pennisetum Purpureum ), and Kikuyu grass ( Pennisetum clandestinum ) were the only grasses that were used in the three zones throughout the year. However, Leersia grass ( Leersia hexandra ) and Rhodes grass ( Chloris gayana ) were only used during the dry season in Eastern Savanna and Central Bugesera zone. The forages harvested from roadside and weeds were the most used (56.1%) followed by the crop residues (28.7%), while the planted forages, were the second least used forages. The only legume forage identified during the study period was Calliandra ( Calliandra Spp ) which contributed up to 0.16% of the overall dry matter intake (DMI). The DMI was higher (p 0.05) within the zones throughout the year. To enhance dairy cow productivity in the Girinka programme, there is a need for introducing and promoting new legumes, grasses, and trees in the region to improve feed supply, especially in dry seasons.

More than half of the applied conventional fertiliser nitrogen (N) in cropping systems can be lost to the environment, resulting in water and air pollution. Farming systems that ensure efficient fertiliser use are crucial to sustain crop productivity without harming the environment. One avenue to achieve this is the use of bio-fertilisers with recognised benefits for plant nutrition and soil heath. Within this area, plant growth promoting rhizobacteria (PGPR) are increasingly applied to enhance plant nutrient acquisition and assimilation. Here, we investigated if PGPR can improve fertiliser performance. We show that the addition of PGPR to soils amended with 50% organic and 50% conventional N fertilisers increased the growth of kikuyu grass (Pennisetum clandestinum), producing yields similar to those obtained using 100% conventional N fertiliser. Encouragingly, this combination also reduced mineral N leaching by 95% relative to the all conventional fertiliser treatment. These findings suggest that using organic and synthetic fertilisers together in the presence of PGPR is a promising approach for sustaining plant growth while reducing potential pollution from inefficient use of conventional N fertilisers.

Resumen Los sistemas de producción de rumiantes en Colombia están soportados en el uso de forrajes, principalmente el kikuyo en el trópico alto (Cenchrus clandestinus, previamente Pennisetum clandestinum). El objetivo de este trabajo fue recopilar la información relacionada con el kikuyo e identificar nuevos campos de investigación que permitan promover un manejo eficiente y sostenible de los sistemas de producción bovino soportados en praderas de kikuyo. Los trabajos sugieren que el kikuyo presenta gran resiliencia ante condiciones ambientales adversas, lo que lo perfilan como una especie de interés ante los nuevos escenarios de variabilidad climática. Además, la literatura reporta estrategias de manejo que promueven el aumento en la producción animal, el mejoramiento en la calidad final del producto y la disminución en el impacto sobre el ambiente. Sin embargo, el kikuyo presenta limitaciones en la respuesta agronómica y composicional que hace necesario desarrollar trabajos de investigación que permitan profundizar en el conocimiento de las relaciones entre las condiciones edafoclimáticas y de manejo que promueva el desarrollo de modelos de optimización de los sistemas de producción. Finalmente, se debe promover programas que permitan conocer las características fenotípicas y genotípicas del kikuyo y definir programas de mejoramiento genético que potencialicen la expresión de esta gramínea en condiciones ambientales específicas. Abstract Colombian ruminants’ systems are supported in grasslands, mainly kikuyu in highlands (Cenchrus clandestinus, previously Pennisetum clandestinum). The objective of this work was to compile information related to kikuyu and identify new research areas to promote an efficient and sustainable ruminants’ systems supported in kikuyu. The literature suggests that kikuyu presents great resilience to adverse environmental conditions, especially in new scenarios of climatic variability. In addition, literature reports management strategies to improve animal production, product quality and reduce environmental impact. However, kikuyu presents limitations of agronomic and compositional response, that makes necessary to develop research works that allow increase knowledge between edafo-climatic relations and management conditions to development optimization models for kikuyu production systems. Finally, it is necessary to promote phenotype and genotype studies and define genetic improvement programs to enhance grass expression under specific environmental conditions. Resumo Os sistemas de produção de ruminantes na Colômbia são baseados na utilização de forragens, principalmente kikuyo nos trópicos superiores (Cenchrus clandestinus, anteriormente Pennisetum clandestinum). O objetivo deste trabalho foi coletar informações relacionadas à kikuyo e identificar novos campos de pesquisa que promovam o manejo eficiente e sustentável de sistemas de produção bovino alimentados com pastagens de kikuyo. Estudos sugerem que o kikuyo tem grande resiliência a condições ambientais adversas, despertando grande interesse tendo em vista os novos cenários de variabilidade climática. Além disso, a literatura relata estratégias de manejo que promovem o aumento da produção animal, a melhoria na qualidade final do produto e a diminuição do impacto no meio ambiente. Entretanto, o kikuyo apresenta limitações no que diz respeito à resposta agronômica e composição necessárias para desenvolver pesquisas que aprofundem a compreensão das relações entre as condições e manejo do solo e o clima que promovam o desenvolvimento de sistemas de modelos de otimização da produção. Finalmente, devem ser desenvolvidos programas que permitam conhecer as características fenotípicas e genotípicas desta forragem, além de definir programas de melhoramento genético que potencializem a expressão dessa gramínea em condições ambientais específicas.

Bu saksı denemesi bazı sıcak iklim çim buğdaygillerinden Uganda (Cynodon dactylon x C.transvaalensis), Yengeçotu (Stenotaphrum secundatum) ve Zenci darısı’na (Pennisetum clandestinum) uygulanan farklı tuz (0-100-200-300 mM) konsantrasyonlarının verim ve beslenme durumu üzerine etkilerini incelemek amacıyla yürütülmüştür. Artan tuzluluk ile tüm çeşitlerin yeşil aksam ve kök kuru ağırlıkları azalmıştır. Aynı şekilde tuzluluk arttıkça en temel üç besin maddesi olan N, P, K element içerikleri de olumsuz bir şekilde etkilenmiştir. Bu çalışmanın sonuçlarına dayanarak, Zenci darısı (Pennisetum clandestinum) çimi 200 mM ve 300 mM tuz uygulamalarından etkilenmesine rağmen, incelenen diğer bitkilere göre tuzluluğa daha yüksek dayanım göstermiştir.

This study was conducted in the municipality of Guachucal, Department of Narino, existing farming systems were characterized, analyzed the function and structure of the tree component and relate tree cover with the intensification of production systems. Stratified farms according to its area, where three strata were obtained: I (0.5 - 3 has), II (3.1 - 6 has) and III (> 6 has). Then applied a stratified sampling using the formula of Ballesteros, with a total of 200 farms, which were classified according to each stratum. To obtain the different diagnoses was a semi-structured survey, which was analyzed using a statistical analysis of major components, multiple correspondence (ACM) and Pearson correlations. The predominantly traditional production system is the perennial ligneous forestry - potato-pasture-bovine milk, characterized by being made with tree species such as: pandala (Clethra sp.), capuli (Prunus cerotina), alder (Alnus acuminata), acacia (Acacia decurrens), eucalyptus (Eucalyptus globulus), Cypress (Cupressus sp.). Regarding grasses predominated the mixture of Pennisetum clandestinum, Holcus lanatus, Lolium multiflorum, and Trifolium repens L; and dominates the race of Holstein cattle. He was also obtained that 95% of farms are paddocks, 100% present mix of native and improved pastures, where the 70.5% manages a production system no stanchion, t 19% and 10.5% stanchion. In the hedgerows, the most representative species of the farms were acacia (Acacia melanoxylom) pine (Pinus patula), used mainly for firewood, poles and wood. The relationship of tree cover with the intensification of production systems is given in a positive way by the area of the estate, area in pasture, cows in production, calf nursing, total production of milk per day, and costs of livestock. Key words: Forestry system, multivariate analysis, hoists cover

The study evaluated small-scale dairy systems with continuous grazing of pastures based on three temperate grasses festulolium (FL), tall fescue (TF), and perennial ryegrass (RG), compared with subtropical kikuyu grass (KG). All pastures were associated with white clover (Trifolium repens L.). Twelve multiparous Holstein cows were assigned to a 4 × 4 Latin square replicated three times with 14-day experimental periods. Sampling and analyses of pastures, concentrates, and animal variables followed standard procedures. FL showed a significantly (p 0.05) higher mean sward height, but there were no differences (p 0.05) in net herbage accumulation. There were significant differences (p 0.05) among pastures for CP, NDF, ADF, in vitro digestibility of OM (IVOMD), and estimated metabolizable energy (eME). There were no differences (p 0.05) between treatments for milk yield and composition, live weight, or body condition score. There were significant differences (p 0.05) in fatty acid values for pastures in C14:0, C16:1, and C18:3n3. There were significant differences between treatments (p 0.05) in milk contents for C18:0, C18:1t11, and C18:2c9t11. Grazing FL, TF, RG, or KY pastures showed no differences in milk yields. Higher values for C18:0, C18:1t11, and C18:2c9t11 were detected in KY, RG, and TF. RG had significantly higher MUFA than FL and higher PUFA than TF. A value under 65% of SFA, a ratio of n-6/n-3 lower than 4, and an atherogenic index of 1.7 are indicators of milk with beneficial effects for human health.

Metal contamination is a recurring problem in Peru, caused mainly by mine tailings from a past active mining activity. The Ancash region has the largest number of environmental liabilities, which mobilizes high levels of metals and acid drainages into soils and freshwater sources, posing a standing risk on human and environmental health. Native plant species spontaneously growing on naturally acidified soils and acid mine tailings show a unique tolerance to high metal concentrations and are thus potential candidates for soil phytoremediation. However, little is known about their propagation capacity and metal accumulation under controlled conditions. In this study, we aimed at characterizing nine native plant species, previously identified as potential hyperaccumulators, from areas impacted by mine tailings in the Ancash region. Plants were grown on mine soils under greenhouse conditions during 5 months, after which the concentration of Cd, Cu, Ni, Pb, and Zn was analyzed in roots, shoots, and soils. The bioaccumulation (BAF) and translocation factor (TF) were calculated to determine the amount of each metal accumulated in the roots and shoots and to identify which species could be better suited for phytoremediation purposes. Soil samples contained high Cd (6.50-49.80 mg/kg), Cu (159.50-1187.00 mg/kg), Ni (3.50-8.70 mg/kg), Pb (1707.00-4243.00 mg/kg), and Zn (909.00-7100.00 mg/kg) concentrations exceeding national environmental quality standards. After exposure to mine tailings, concentrations of metals in shoots were highest in Werneria nubigena (Cd, 16.68 mg/kg; Cu, 41.36 mg/kg; Ni, 26.85 mg/kg; Zn, 1691.03 mg/kg), Pennisetum clandestinum (Pb, 236.86 mg/kg), and Medicago lupulina (Zn, 1078.10 mg/kg). Metal concentrations in the roots were highest in Juncus bufonius (Cd, 34.34 mg/kg; Cu, 251.07 mg/kg; Ni, 6.60 mg/kg; Pb, 718.44 mg/kg) and M. lupulina (Zn, 2415.73 mg/kg). The greatest BAF was calculated for W. nubigena (Cd, 1.92; Cu, 1.20; Ni, 6.50; Zn, 3.50) and J. bufonius (Ni, 3.02; Zn, 1.30); BCF for Calamagrostis recta (Cd, 1.09; Cu, 1.80; Ni, 1.09), J. bufonius (Cd, 3.91; Cu, 1.79; Ni, 18.36), and Achyrocline alata (Ni, 137; Zn, 1.85); and TF for W. nubigena (Cd, 2.36; Cu, 1.70; Ni, 2.42; Pb, 1.17; Zn, 1.43), A. alata (Cd, 1.14; Pb, 1.94), J. bufonius (Ni, 2.72; Zn, 1.63), and P. clandestinum (Zn, 1.14). Our results suggest that these plant species have a great potential for soil phytoremediation, given their capability to accumulate and transfer metals and their tolerance to highly metal-polluted environments in the Andean region.

Made available in DSpace on 2018-12-11T17:15:08Z (GMT). No. of bitstreams: 0 Previous issue date: 2017-10-03 The challenge of agricultural sector is to reduce greenhouse gas (GHG) emissions while increasing food, fiber and energy production without jeopardizing environmental integrity. In the Andean zone of Colombia, there is a growing need to develop GHG mitigation techniques associated with milk production. The present study focuses on GHG emissions and potential sinks associated with milk production scenarios in the Andean zone of Colombia. The scenarios considered were as follows: conventional agriculture of Pennisetum clandestinum in rotation with potatoes (PRP), improved pastures of Lolium multiflorum (IP) and silvopastoral system of P. clandestinum in association with Acacia decurrens and Trifolium repens (SPS). Based on the IPCC (Guidelines for national greenhouse gas inventories. The intergovernmental panel on climate change, Institute for Global Environmental Strategies, Kanagawa, 2006. http://www.ipcc-nggip.iges.or.jp/support/Primer_2006GLs.pdf) methodologies, the annual GHG emissions considering a 6-year production cycle included agricultural sources and gasoline consumption related to the most important agricultural phases in the field, and a potential for soil carbon accumulation and biomass carbon fixation in all the studied scenarios. The lowest GHG emissions were estimated in PRP scenario (3684 kg CO2-eq ha−1 year−1), which also presented additional emissions because of soil carbon losses beyond the lower milk productivity. Highest GHG emissions were observed in IP scenario (7711 kg CO2-eq ha−1 year−1), which exhibited the highest milk productivity and a considerable potential for soil carbon accumulation that could help to offset its emissions. Nevertheless, SPS scenario, which had milk productivity close to that of IP, presented the highest potential to offset the total GHG emission (4878 kg CO2-eq ha−1 year−1) because of soil carbon accumulation and biomass carbon fixation in trees. This study contributed to indicate management strategies that should be prioritized to mitigate the main sources of GHG emission in the extensive and intensive dairy cattle production in the Andean region of Colombia. Department of Exact Sciences College of Agricultural and Veterinarian Sciences São Paulo State University FCAV/UNESP), Via de Acesso Prof. Paulo Donato Castellane s/n Department of Rural Development Centro do Ciências Agrárias Federal University of São Carlos (UFSCar), Rodovia Anhanguera, km 174 Brazilian Bioethanol Science and Technology Laboratory/Brazilian Center for Research in Energy and Materials (CTBE/CNPEM), Rua Giuseppe Máximo Scolfaro 10000, Polo II de Alta Tecnologia Department of Exact Sciences College of Agricultural and Veterinarian Sciences São Paulo State University FCAV/UNESP), Via de Acesso Prof. Paulo Donato Castellane s/n

El objetivo de esta investigación fue evaluar la cinética de degradación ruminal de los nutrientes in situ, así como la digestibilidad aparente de los nutrientes, población de protozoarios del rumen y producción de gas in vitro de dietas a base de biomasa poscosecha de Amaranthus cruentus. La biomasa pos-cosecha del A. cruentus con el forraje de Pennisetum clandestinum se mezcló en base seca de acuerdo a los siguientes tratamientos: T1: 100% A. cruentus, T2: 100% P. clandestinum, T3: 75% P. clandestinum + 25% A. cruentus, T4: 50% P. clandestinum + 50% A. cruentus, bajo un diseño completamente aleatorizado. Los parámetros de degradación ruminal muestran diferencias entre tratamientos (p, The aim of this research was to evaluate the in situ rumen degradation kinetics of nutrients, as well as the apparent digestibility of nutrients, population of rumen protozoa, and in vitro gas production of based diets from post-harvest biomass of Amaranthus cruentus. Post-harvest biomass of A. cruentus with Pennisetum clandestinum forage was mixed in dry basis according to four treatments: T1: 100% A. cruentus, T2: 100% P. clandestinum, T3: 75% P. clandestinum + 25% A. cruentus, T4: 50% P. clandestinum + 50% A. cruentus, under a completely randomized design. The ruminal degradation parameters showed differences between treatments (p