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We investigated the type and extent of degradation at three sites on the Agulhas Plain, South Africa: an old field dominated by the alien grass Pennisetum clandestinum Pers. (kikuyu), an abandoned Eucalyptus plantation, and a natural fynbos community invaded by nitrogen fixing-Australian Acacia species. These forms of degradation are representative of many areas in the region. By identifying the nature and degree of ecosystem degradation we aimed to determine appropriate strategies for restoration in this biodiversity hotspot. Vegetation surveys were conducted at degraded sites and carefully selected reference sites. Soil-stored propagule seed banks and macro- and micro-soil nutrients were determined. Species richness, diversity and native cover under Eucalyptus were extremely low compared to the reference site and alterations of the soil nutrients were the most severe. The cover of indigenous species under Acacia did not differ significantly from that in reference sites, but species richness was lower under Acacia and soils were considerably enriched. Native species richness was much lower in the kikuyu site, but soil nutrient status was similar to the reference site. Removal of the alien species alone may be sufficient to re-initiate ecosystem recovery at the kikuyu site, whereas active restoration is required to restore functioning ecosystems dominated by native species in the Acacia thicket and the Eucalyptus plantation. To restore native plant communities we suggest burning, mulching with sawdust and sowing of native species.

The effectiveness of four granular wetting agents to decrease water repellency in sandy soils of contrasting organic matter (OM) content and influences on kikuyugrass [Pennisetum clandestinum (Holst. Ex Chiov)] grown as turfgrass, were evaluated. A laboratory test assessed the wettability of two non-wetting soils (low OM, 4.7%; high OM, 17%) after treatment with granular soil wetting agents, with four being selected for field experimentation. A field experiment included two turfgrass ages (established from 20 week or 20 year old turfgrass in 2005; the latter included a 50 mm ‘mat’ layer and thus had high OM content in the surface soil), four granular soil wetting agents (plus a ‘nil’ as control), and five replicates. Surface soil (0–25 mm) water repellency, measured using the molarity of ethanol droplet test (MED), ranged from 0.4 M to 4.3 M during the irrigation season, and repellency was more severe in the soil with high OM (32%) content than low OM (8.6%) content. Soil wetting agents decreased the development of soil water repellency to varying extents, and maintained turfgrass quality; with improvement related to the amount of active ingredient applied. We recommend utilising an effective soil wetting agent, in combination with practices that limit the accumulation of soil OM, to decrease the severity and incidence of soil water repellency in turfgrass grown on sandy soils.

The feeding behaviour of Xhosa lop-eared (XLE), Nguni (NGN) and Nguni × Boer crossbred (NBC) goat genotypes was compared in a False Thornveld rangeland by recording time spent on browsing, grazing and other non-foraging activities in four seasons; cool-dry (June to August); hot-dry (September to October), hot-wet (November to February) and post-rainy (March to May). The False Thornveld rangeland consists of diverse plant species dominated by Acacia karroo , Grewia occidentalis , Scurtia myrtina Themeda triandra , Panicum maximum , Digitaria eriantha , Eragrostis spp., Cynodon dactylon and Pennisetum clandestinum , and receives an annual rainfall of not more than 490 mm. Four observers monitored 8 goats per genotype at 15-minute intervals for 4 h (0800–1200 h) in the morning and 4 h (1200–1600 h) in the afternoon. Genotype, season and time of day had an effect on the feeding behaviour of goats on the rangeland (P

Gray leaf spot (GLS) disease of perennial ryegrass (Lolium perenne) and kikuyugrass (Pennisetum clandestinum) in golf courses in California was first noted in 2001 and 2003, respectively, and within 5 years had become well established. The causal agent of the disease is the fungus Magnaporthe grisea, which is known to consist primarily of clonal lineages that are highly host specific. Therefore, our objective was to investigate host specificity and population dynamics among isolates associated primarily from perennial ryegrass and kikuyugrass since the disease emerged at similar times in California. We also obtained isolates from additional hosts (tall fescue, St. Augustinegrass, weeping lovegrass, and rice) and from the eastern United States for comparative purposes. A total of 38 polymorphic amplified fragment length polymorphism makers were scored from 450 isolates which clustered by host with high bootstrap support (71 to 100%). Genetic structure between kikuyugrass and perennial ryegrass isolates differed significantly. Isolates from kikuyugrass were genotypically diverse (n = 34), possessed both mating types, and some tests for random mating could not be rejected, whereas isolates from perennial ryegrass were less genotypically diverse (n = 10) and only consisted of a single mating type. Low genotypic diversity was also found among the other host specific isolates which also only consisted of a single mating type. This is the first study to document evidence for the potential of sexual reproduction to occur in M. grisea isolates not associated with rice (Oryza sativa). Moreover, given the significant host specificity and contrasting genetic structures between turfgrass-associated isolates, the recent emergence of GLS on various grass hosts in California suggests that potential cultural practices or environmental changes have become conducive for the disease and that the primary inoculum may have already been present in the state, despite the fact that two genotypes associated with perennial ryegrass and St. Augustinegrass in California were the same as isolates collected from the eastern United States.

A common lawn grass; kikuyu grass, an abundant vegetable; cabbage and vallisneria a common macrophyte were tested for utilisation by two size classes of a herbivorous fish, Tilapia rendalli held in glass aquarium tanks. The test feeds were given to sub-adult T. rendalli for 133 days at 8% body weight and juvenile fish for 84 days at 15% body weight. Sub-adult and juvenile fish fed kikuyu grass attained a higher specific growth rate, higher protein efficiency ratio and better food conversion ratio than those fed cabbage and vallisneria. This is explained by the differences in the protein content, higher levels of lysine and the sulphur-containing amino acid, methionine in kikuyu grass. Palatability studies of the juveniles also showed that kikuyu was most preferred. However, sub-adults preferred vallisneria, kikuyu and cabbage respectively. The possible reasons for the selection are discussed.

Green leaves of six grass species in temperate Australia showed considerable circadian variation (especially in summer) in water content, which peaked late in the night and fell from sunrise to an afternoon minimum. In summer, water content of a set of ‘wetter’ species (Axonopus affinis, Pennisetum clandestinum and Paspalum dilatatum) was consistently higher and varied less profoundly through the 24 h than that of a ‘drier’ set (Imperata cylindrica, Poa labillardieri and Themeda triandra). Hour-to-hour and day-to-day variation in leaf water content of P. dilatatum in summer partly but imperfectly reflected ambient temperature. Recognizing the risks for herbivores of visiting water sources, we considered leaf water content as a source of free water for leaf-grazing herbivores, eastern grey kangaroos Macropus giganteus and common wombats Vombatus ursinus. Using known field metabolic rates, energy requirements and digestive efficiencies, we calculated these two species' free-water intakes when satisfying their energy needs with these grasses but distributing their grazing in different schedules. Both species would obtain more free water by their observed foraging schedules than by random or daytime-only schedules. We calculated that the measured grasses could satisfy the water requirements of wombats but not always those of kangaroos, who would need to drink when forage water content was less than about 70%. Water content of grass leaf could rise above and fall below this value within a day, creating some scope for kangaroos to manage their need to visit water by adjusting foraging schedules or choice of grass species. In future studies, circadian variation in leaf water content should be considered as a factor (together with their thermal physiology) driving herbivores' activity scheduling, and affecting their dietary selection.

Disturbance is a key component of many successful plant invasions. However, interactions among natural and anthropogenic disturbances and effects of these interacting disturbances on invasive plants and desired vegetation are rarely examined. We investigated the effect of anthropogenic disturbance (herbicidal and mechanical) along a natural inundation gradient (20-282 days) on the biomass and resource allocation of the invasive wetland plant, alligator weed (Alternanthera philoxeroides), and two co-occurring competitor plants, the introduced grass, kikuyu (Pennisetum clandestinum), and the native grass, couch (Cynodon dactylon), over a 2-year period. In the absence of additional disturbance, kikuyu biomass was negatively affected, alligator weed biomass was positively affected, and couch biomass was not affected by inundation disturbance. In addition, kikuyu was not affected by the selective removal of alligator weed, while couch increased in wetter habitats where kikuyu was absent due to inundation stress. This suggests that kikuyu is a superior competitor in drier habitats and inundation facilitates the invasion of alligator weed, while couch is an inferior competitor to both kikuyu and alligator weed and is therefore suppressed across its entire niche by these two introduced species. Mowing alone had no effect on the biomass of the species, suggesting the plants are equally tolerant of shoot removal. Selective herbicide reduced alligator weed biomass by 97.5% and the combination of selective herbicide and mowing reduced the biomass of alligator weed significantly more than herbicide alone, by 98.6% compared with un-manipulated controls. To predict community change and prevent sequential exotic plant invasions after weed removal, it is necessary to consider the interacting effects of disturbance and the niche space of invasive species in the local propagule pool.

Grass eating behaviour in the domestic dog may be related to gastrointestinal distress. To explore this theory, the current study observed grass eating behaviours in dogs fed a standard diet with and without supplementation of a fructo-oligosaccharide (FOS). The FOS diet temporarily induced loose, watery stools to simulate a mild gastrointestinal disturbance. During both FOS Diet and Standard Diet periods, dogs were presented with couch (Cynodon dactylon) and kikuyu (Pennisetum clandestinum) grasses, and the time spent eating grass and the number of grass eating and vomiting events was recorded. Our study found that dogs spent significantly more time eating grass when fed the standard diet and producing normal stools than when they were fed the FOS diet and producing loose stools, suggesting that dogs do not use grass to self-medicate a diarrhoeal gastrointestinal disturbance. However, this does not preclude that other forms of gastrointestinal disturbance may be self-medicated by grass eating behaviours. Importantly, dogs did not use grass as an emetic, as there were only two vomiting events and 374 grass eating events observed. Alternatively, the reduction in grass eating may be attributable to a feeling of satiety caused by the fermentation of FOS. For further clarity, future research should examine the effect of other gastrointestinal disturbances, such as constipation (hard, dry stools) or nausea, on grass eating behaviour in the domestic dog.

Eighteen crossbred (Chegu×Jamunapari) goats (15.99 kg; 7–9 months) were randomly assigned to three groups. The animals were fed a common concentrate mixture as a supplement to three different forage sources (with a concentrate to roughage ratio of 30: 70) namely, green grass (PC, Pennisetum clandestinum), oak leaves i.e. Quercus semecarpifolia (QS) and Quercus leucotricophora (QL) with the latter two groups serving as tannin-containing diets while the PC group as a control. The condensed and hydrolysable tannin content of the QS and QL diets was CT 1, HT 3.4 vs. CT 1.9, HT 1.6, respectively. A metabolism trial of six days duration was conducted at 90 d post-feeding. Blood samples were collected on 0, 60 and 120 d of experiment for estimation of serum minerals. The digestibility of DM, CP and fibre fractions were lower (P

Management plans for the grazed parklands of the Auckland volcanic cones call for revegetation to restore a more natural and historic vegetation cover. The native grass Microlaena stipoides has been identified as a relevant species, and a field experiment was undertaken to determine the best approach for establishing this species into existing pasture. Seed obtained locally was broadcast or hydro-seeded in May 2007 onto kikuyu pasture, at three sowing rates (100, 250 and 750 seeds/m2) following control of the resident pasture with turf stripping or mowing and spraying, in a replicated factorial trial. After 12 months, the highest levels of Microlaena plant density (mean 56 plants/m2), cover (mean 50%) and accumulated herbage mass were observed on broadcast/sprayed plots at the highest sowing rate. Recovery of the resident pasture (dominantly Pennisetum clandestinum) occurred to a level of ~25% after 12 months, but was inhibited at the highest Microlaena sowing rate. Keywords: broadcast, hydro-seeding, kikuyu, Microlaena stipoides, re-vegetation

Little is known of the life history of the edible stinkbug, Encosternum delegorguei, although it is an important food for people living in north-eastern South Africa and southern Zimbabwe. The present study aimed to establish key elements influencing long-term sustainable harvesting. Outdoor insectaries of two sizes were constructed to observe: daily activity, utilization of plants, copulation, oviposition, eclosion and survival from May 2006 to February 2007. The rest of the annual life cycle was observed in the field in March and April 2007 and identified as univoltine. In autumn (May) E. delegorguei entered reproductive diapause and aggregated within the escarpment mist-belt where it survived the winter on vapour condensation without feeding. Monthly dissections showed that abdominal fat content was highest in June. In spring (September) E. delegorguei fed on sap of the trees Combretum imberbe, Combretum molle, Peltophorum africanum, to a lesser degree on Dodonaea viscosa and the grass Pennisetum clandestinum. Copulation occurred in October and November. An overall total of 1752 E. delegorguei eggs were laid by 103 females and incubation time averaged 18.7 ± 9.0 days (range 7-37) at outdoor temperature ranging from 11°C to 25°C. The mean number of eggs in 64 egg masses was 27.4 ± 13.9 (range of 2-56 eggs). Shade cloth (68.8%) was the most commonly used substrate for depositing eggs followed by P. clandestinum (12.5%), C. imberbe (7.8%), P. africanum (6.3%), D. viseosa (1.6%), C. molle (1.6%) and C. erytltrophyllum (1.6%). The parasitoid wasp, Anastatus sp. (Hymenoptera: Eupelmidae) infected 57% of the eggs deposited by captive females. Availability of food plants in combination with parasitoid threat may be a reason for seasonal migration between overwintering sites within the mist-belt and summer oviposition sites. Diminishing harvests could be attributed to fuelwood harvesting of food plants in the summer sites.

The conversion of montane cloud forests into pastures for grazing cattle is the main cause of important impacts on rivers and streams in most of the Andes. In order to evaluate the effects of vegetation changes we need to understand water fluxes, particularly canopy interception. We measured net precipitation responses by the canopies of Pennisetum clandestinum Hochst. ex Chiov. and Melinis minutiflora Beauv. under simulated rainfall. The samples were taken from grazed pastures during 1 year, digging out round mats of grass, placing them on wire-mesh devices after eliminating soil and underground biomass, and irrigating with different water amounts. The resulting data allow us to present a validated model for each species that predicts percentage of interception at different precipitation intensities taking into account previous canopy wetness within determined biomass ranges. We use these models to estimate 2 years of interception values for pastures of both species in the upper watershed of El Canadon, Capaz River, Venezuelan Andes. Mean annual precipitation of El Canadon is 1244 mm and the estimate of pasture interception was 36.5% and 31.8% for P. clandestinum and M. minutiflora , respectively. Interception models, such as the ones derived in this study, provide a basis for quantifying interception rates as a function of previous wetness of canopies and grass species.

Kikuyugrass (Pennisetum clandestinum Hochst. ex Chiov.) is an active silicon (Si) accumulator, and Si can reduce the organic‐matter digestibility of forage grasses. Calcium carbonate (crushed coral) applications to a low Si Maile silt loam soil (Acrudoxic Hydrudands) had no effect on the in vitro digestible organic matter (IVDOM) concentration of 3‐week‐old (4.5‐leaf‐per‐tiller stage of development) ‘Whittet’ kikuyugrass regrowth, whereas calcium silicate (wollastonite) applied at the calcium equivalent of the calcium carbonate rates produced a curvilinear (crescent‐shaped quadratic) IVDOM response. Whittet IVDOM decreased when grass Si concentration exceeded about 22 g kg−1 or when 0.5 M acetic acid–extractable soil Si exceeded about 230 mg kg−1. Common and ‘Hosaka’ kikuyugrass regrowth on the Maile soil had less Si and greater IVDOM concentrations than those observed for high‐Si Kohala (Humic Dystrustepts) and Waialua (Pachic Haplustolls) silty clay soils. Whittet had greater crude protein and IVDOM con...

En esta investigación se determinó el balance de nitrógeno en dos tipos de pasturas de clima frío: una pastura mixta de dos gramíneas -kikuyo (Pennisetum clandestinum) y festuca alta (Festuca arundinacea)- y pastura asociada de la gramínea festuca alta más la leguminosa trébol pata de pájaro (Lotus uliginosus), en un área de 1 ha cada una, con un diseño al azar con la vaca como unidad experimental y la pastura como tratamiento. Se emplearon cinco vacas Holstein para cada tratamiento durante un período experimental de 14 días. Se determinó la producción de biomasa (g MS/m2), cantidad de nitrógeno en la pastura, suplemento, salidas en heces, orina y leche, y el valor de eficiencia de uso del nitrógeno por los animales. En el balance del nitrógeno en el animal, se observó mejor eficiencia en su uso en la pastura asociada comparada con la pastura mixta, y cambios en las vías de excreción, siendo mayor la salida en orina de los alimentados con pastura mixta y mayor en leche en los alimentados con la asociada. El balance de nitrógeno en la pastura in situ se realizó con un modelo de simulación, empleando los valores determinados en este ensayo, y se observó que fue positivo para la pastura asociada frente a la mixta; esto indica menor necesidad de nitrógeno externo en la pastura asociada. La pastura asociada mejoró la eficiencia de uso del nitrógeno en ganado para leche y presentó un balance positivo en el sistema de pastura.

SUMMARYA 3-year experiment (2005–07) was conducted on Reunion Island (France) to evaluate the effect of species, climate and fertilization levels on fibre and protein fractions of tropical (C4;Chloris gayanaandPennisetum clandestinum) and temperate (C3;Dactylis glomerataandLotium multiflorum) grasses. A near infrared reflectance spectroscopy (NIRS) prediction referential was developed to estimate neutral detergent fibre (NDF), acid detergent fibre (ADF), crude protein (CP), NDF insoluble protein (NDF-IP) and ADF insoluble protein (ADF-IP). The NIRS equations were then used to screen many regrowth grass samples collected at heading stage continuously for 3 years to evaluate their changes during the seasons. Results showed that grass species differed significantly in fibre and protein fractions. NDF, ADF and ADF-IP were the lowest inD. glomerata/L. multiflorumand the highest inC. gayana. The wet season was associated with higher NDF, ADF and NDF-IP inD. glomerata/L. multiflorumand lower NDF-IP inP. clandestinum.Fertilization increased the CP inC. gayanaand the NDF-IP inP. clandestinum, but decreased the ADF-IP of bothC. gayanaandD. glomerata/L. multiflorum. Growth rate strongly changed NDF, ADF, NDF-IP and ADF-IP although no change in CP appeared. In general, NDF, ADF and NDF-IP increased with the growth rate. In contrast, the ADF-IP content decreased from slow to fast growth rate inC. gayanaandD. glomerata/L. multiflorum. Growth rate changes were thus considered as a general indicator for fibre and protein fraction variations of these grasses.

Many studies have demonstrated that reduced light availability, which can be manipulated at local scales by planting or seeding canopy species, can curtail the growth of invasive species and promote the growth of native species. Species differences in functional traits, such as light use and stress tolerance, may be used to determine how native and invasive species will respond to these resource manipulations. We altered light availability in a mesic Hawaiian forest understory and found that low light levels reduced the biomass and growth of two invasive grasses (Pennisetum clandestinum and Ehrharta stipoides) relative to two native shrubs (Pipturus albidus and Coprosma rhynchocarpa) and two native canopy species (Metrosideros polymorpha and Acacia koa). Native species generally displayed traits associated with shade tolerance (high quantum yield, chlorophyll content, and leaf mass per area), whereas the two invasive grasses displayed traits associated with shade intolerance (high photosynthetic rate and growth rate). Several key traits pertaining to light acquisition and shade tolerance (quantum yield, chlorophyll content, and leaf mass per area) predicted seedling survival in low-light treatments. Our data suggest that differences in light use among native and invasive species can help to determine the utility of resource manipulation as a restoration tool and, more specifically, to predict which native species will be optimal for restoration efforts that manipulate light availability.

Eight castrated male lambs (35 ± 4 kg live weight), fed a basal diet of kikuyu grass hay, were used in a replicated 4 × 4 Latin Square experiment with a 2 × 2 factorial arrangement of treatments to evaluate the effect of supplemental feeding frequency and source of rumen degradable N on intake, digestibility, ruminal fermentation, and microbial protein yield. Treatments were supplementation with cassava meal plus calcium caseinate or cassava meal plus urea offered at a rate of 7 g/kg live weight daily in one or two meals per day. Lambs were fed twice daily in such manner to allow ad libitum comsumption of forage. There was significant feeding frequency by N source interaction on variables of intake. In general, intake of feed components was higher (P ≤ 0.05) by lambs offered the caseinate-supplement twice daily over intake observed in lambs given the others diet treatments. Digestibility of feed components was neither affected by supplemental N source (DM, P = 0.541; OM, P = 0.585; NDF, P = 0.828) nor by feeding frequency (DM, P = 0.122; OM, P = 0.175; NDF, P = 0.591). Urinary excretion of N increased (P ≤ 0.05) in lambs supplemented twice daily whereas N retention was similar for all treatments (N source, P = 0.748; feeding frequency, P = 0.418). Microbial protein entering into the small intestine was affected by the interaction between feeding frequency and N source such as an increasing (P

Excessive thatch and mat can be detrimental to turfgrass health and management. Mechanical and topdressingtechniques to reduce accumulation of thatch and mat were evaluated in a 24-mo field study ofkikuyu [Pennisetum clandestinum (Hochst. ex Chiov.)] turfgrass of two contrasting organic matter (OM) contents in the surface 50 mm of soil. Treatments included two kikuyugrass ages (established from 20 wk or 20-yr-old kikuyugrass) and five renovation techniques (none, verticutting, coring, topdressing with sand, coring + topdressing). The renovation techniques varied in effectiveness depending on the initial OM content of the soil immediately underlying the kikuyugrass. Annual verticutting, or twice annual topdressing with or without annual coring a young kikuyugrass were most successful at restricting the accumulation of soil OM (P < 0.05), with OM content

Temperate species and tropical crop silage are the basis for forage production for the dairy industry in the Australian subtropics. Irrigation is the key resource needed for production, with little survival of temperate species under rain-grown conditions except for lucerne. Annual ryegrass (Lolium multiflorum), fertilised with either inorganic nitrogen or grown with clovers, is the main cool season forage for the dairy industry. It is sown into fully prepared seedbeds, oversown into tropical grasses, especially kikuyu (Pennisetum clandestinum) or sown after mulching. There has been a continual improvement in the performance of annual and hybrid ryegrass cultivars over the last 25 years. In small plot, cutting experiments, yields of annual ryegrass typically range from 15 to 21 t DM/ha, with equivalent on-farm yields of 7 to 14 t DM/ha of utilised material. Rust (Puccinia coronata) remains the major concern although resistance is more stable than in oats. There have also been major improvements in the performance of perennial ryegrass (L. perenne) cultivars although their persistence under grazing is insufficient to make them a reliable forage source for the subtropics. On the other hand, tall fescue (Festuca arundinacea) and prairie grass (Bromus willdenowii) cultivars perform well under cutting and grazing, although farmer resistance to the use of tall fescue is strong. White clover (Trifolium repens) is a reliable and persistent performer although disease usually reduces its performance in the third year after sowing. Persian (Shaftal) annual clover (T. resupinatum) gives good winter production but the performance of berseem clover (T. alexandrinum) is less reliable and the sub clovers (T. subterraneum) are generally not suited to clay soils of neutral to alkaline pH. Lucerne (Medicago sativa), either as a pure stand or in mixtures, is a high producing legume under both irrigation and natural rainfall. Understanding the importance of leaf and crown diseases, and the development of resistant cultivars, have been the reasons for its reliability. Insects on temperate species are not as serious a problem in the subtropics as in New Zealand (NZ). Fungal and viral diseases, on the other hand, cause many problems and forage performance would benefit from more research into resistance.

Atributos químicos e físicos de um Nitossolo Vermelho Eutrófico léptico argiloso foram avaliados em Passo Fundo (RS) em um experimento sobre o desempenho agronômico de três gramíneas perenes de verão (capim quicuio, capim elefante e capim Tifton 68) para a produção de leite após duas estações de crescimento. O delineamento experimental foi em blocos ao acaso com quatro repetições. Avaliou-se também o solo sob floresta subtropical em área adjacente ao experimento. Os valores de pH, Al, Ca e Mg trocáveis, e P extraível diferiram, em algumas camadas, entre as pastagens estudadas. Algumas pastagens, em relação à floresta nativa favoreceram a elevação do teor de P, em todas as camadas avaliadas. Entre as pastagens, não houve diferença significativa para o teor de carbono do solo. Sob capins houve maior acúmulo de carbono, na camada de 0-20 cm do solo, em comparação à floresta. A densidade do solo e a resistência à penetração não diferiram entre as pastagens, em ambas as camadas, porém nas camadas de 0 a 5 cm e na de 10 a 15 cm, houve aumento desses valores, em relação à floresta subtropical. As porosidades totais e a macroporosidade não diferiram entre as três espécies de pastagens, mas houve redução dos valores em comparação com a floresta subtropical.Soil chemical and physical characteristics were evaluated on a Rhodic Nitisol Eutrophic clayey located in Passo Fundo, Rio Grande do Sul State, Brazil in a trial of agronomic performance of three perennial summer grasses (kikuyu grass, elephant grass and Tifton 68 grass) for milk production after two growing seasons. The trial used a complete randomized block design replicated three times. Soil samples were also taken in a fragment of subtropical forest near the experiment. Soil reaction (pH), aluminum, calcium, magnesium, and phosphorus varied according to the studied soil layer. Some grasses increased the level of phosphorus content in all layers. Pastures increased accumulated carbon levels in the 0-20 cm layer in comparison to subtropical forest. No differences among grass species were observed for soil organic matter contents. Soil bulk density and soil mechanical resistance did not differ among pastures in both sampling layers. However, in the 0-5 cm layer (and in the 10-15 cm), these values increased in comparison to the subtropical forest. Total porosity and macroporosity did not differ among of three grass species, but the values were respectively lower and greater in comparison to soil forest.

A monitoring programme for the tropical grass webworm (TGW) (Herpetogramma licarsisalis) has been operating in the Far North since 1999, when high densities of the larva resulted in severe defoliation of large areas of kikuyu (Pennisetum clandestinum) pasture. Keywords: tropical grass webworm, kikuyu, pheromone, monitoring programme

The effect ofN fertilizer rate on Kikuyu turfgrass [Pennisetum clandestinum (Hochst. ex Chiov)] evapotranspiration was evaluated during two summers. Evapotranspiration was measured using weighing lysimeters (205 mm in diameter by 625 mm in length) inserted in turfgrass field plots (10 m 2 ). The experiment was a randomized plot design with three replicates. Treatments included two turfgrass ages (established from 20 wk or 20-yr-old turfgrass) and three N application rates (0, 50, or 150 kg N ha -1 yr -1 ). Evapotranspiration ranged from 2.8 to 7.5 mm d -1 (or 56-81% of evaporative demand),and varied with daily evaporative demand, turfgrass age, and N fertilizer rate. The older turfgrass used more water than the younger turfgrass during both summers; while increasing the N application rate also increased evapotranspiration for both turfgrass types (younger turfgrass only in the second summer). Evapotranspiration was positively correlated with turfgrass growth (r 2 = 0.74-0.80) and transpiring leaf area (r 2 = 0.78). Older turfgrass at all N treatments, and the younger turfgrass receiving 150 kg N ha -1 yr -1 , had adequate growth, color, and leaf N concentrations. Optimizing fertilizer applications such that the minimum N required to maintain turfgrass quality is applied, is an approach for decreasing water consumption by turfgrass.

The high dry matter yield of kikuyu (Pennisetum clandestinum) under favourable conditions supports high stocking rates and milk production per hectare. However, the quality of kikuyu is generally low and consequently the milk production per cow is also low. The aim of the study was to determine the grazing capacity, milk production and milk composition from kikuyu, kikuyu over-sown with annual ryegrass (Lolium multiflorum var. westerwoldicum), kikuyu over-sown with a mixture of perennial ryegrass (L. perenne), white clover (Trifolium repens) and red clover (T. pratense), and kikuyu over-sown with a mixture of white and red clovers. Milk production per cow was highest on pasture with high clover content and the grazing capacity of pasture increased as the grass component increased. The milk produced from kikuyu during spring (15 kg cow–1 d–1) and summer (14.4 kg cow–1 d–1) was higher than during the autumn (12.1 kg cow–1 d–1). The total milk production from kikuyu during spring (3 876 kg milk ha–1) increased when kikuyu was over-sown with annual ryegrass (8 133 kg milk ha–1) or with clover (7 370 kg milk ha–1). The summer and autumn grazing capacity of kikuyu and kikuyu–annual ryegrass fertilised with nitrogen was higher than the kikuyu–clover pastures not receiving nitrogen. The clover content of the pastures did not affect the milk protein or butterfat content. The mean annual grazing capacity of kikuyu (6.7 cows ha–1) and kikuyu–annual ryegrass (8 cows ha–1) pasture was higher than the kikuyu clover (5.3 cows ha–1) pasture. The grazing capacity and milk production per cow from kikuyu over-sown with ryegrass varied less than from kikuyu or kikuyu–clover pastures. This resulted in a similar or higher milk production per hectare from kikuyu–ryegrass compared to that of kikuyu or kikuyu–clover pastures. Keywords: annual ryegrass, butterfat, kikuyu, milk, milk protein, perennial ryegrass, red clover, white cloverAfrican Journal of Range & Forage Science 2008, 25(3): 103–110

The effects of N fertiliser regimes on N leaching and turfgrass quality during the establishment and maintenance of Kikuyu turfgrass (Pennisetum clandestinum (Holst. Ex Chiov)) were evaluated in a 24 month field study. Treatments included two turfgrass ages (established from 20 week or 20 year old turfgrass, the later included a 50 mm ‘mat’ layer), three N application rates (50, 100 or 150 kg N ha−1 yr−1) and three application frequencies (every 4 weeks, 4 applications per year, 2 applications per year); and included turfgrass plots that received no N fertiliser. Nitrogen leaching, measured using soil lysimeters, ranged from 35 to 69 kg N ha−1 by the end of 24 months, and varied with turfgrass age, but not N fertiliser regime. Greatest N losses occurred during turfgrass establishment, with up to 50% of all N leached in the organic form. We recommend measuring both total N and mineral N when assessing N leaching from turfgrass. The quality of the older turfgrass was maintained using less N fertiliser than the younger turfgrass, while increasing N application frequency improved the consistency of turfgrass growth and colour.

The changes in chemical composition of hay of kikuyu grass (Pennisetum clandestinum) harvested at 50, 70 and 90 d of regrowth, and its effect on intake, digestibility, fermentation and microbial protein synthesis in the rumen (Experiment 1) and oxygen uptake by portaldrained viscera (PDV) (Experiment 2) were evaluated. The experiments were carried out with Polwarth · Texel crossbreed lambs with a mean live weight (s.e.m.) of 35(3AE0) kg housed in metabolic cages. Organic matter (OM), neutral-detergent fibre (NDF) and nitrogen (N) intake, as well as rumen ammonia-N concentration, decreased linearly with age of regrowth (P

Com o objetivo de avaliar a rentabilidade da produção de leite no sistema de produção integração lavourapecuária, foi conduzido um experimento, no período de julho de 2004 a abril de 2005, em Castro, Paraná. O delineamento utilizado foi de blocos ao acaso com quatro tratamentos e três repetições, com os tratamentos correspondendo a diferentes níveis de suplementação. Os tratamentos utilizados foram: 1 – pastagem + 20% de suplementação, com Dieta Total Misturada (DTM), suficiente para mantença e produção de 28 litros vaca -1dia-1; 2 – pastagem + 45% de suplementação; 3 – pastagem + 65% de suplementação; e 4 – pastagem + 100% de suplementação. A área experimental utilizada foi de 32,40ha, com 22,4ha no inverno, implantada com o consórcio azevém anual (Lolium multiflorum L.) e aveia preta (Avena strigosa Schreb.), dividida em 12 piquetes. No verão foi utilizada área de 10,0ha, com Quicuio (Pennisetum clandestinum), dividida também em 12 piquetes. Em cada repetição, foram utilizados quatro animais “testers”, sendo três vacas da raça HPB e uma da raça Jérsei. O sistema de pastejo adotado foi o de lotação contínua, com carga variável. Foram utilizados animais reguladores para controlar a altura do pasto, mantida em torno de 20cm. Foram avaliadas, duas vezes por semana, a produção individual de leite das vacas, e a cada duas semanas a percentagem de gordura, a percentagem de proteína e a contagem de células somáticas no leite. A análise econômica foi realizada utilizando a metodologia proposta pelo Sistema de Acompanhamento do Custo de Produção de Leite no Paraná – FAEP. O tratamento 1, com 20% de suplementação, apresentou o melhor resultado econômico, com custo operacional total de R$ 0,4635 litro-1, e margem líquida de R$ 0,13 litro-1. Aiming to evaluate the profitability of milk production under an integrated dairy-crop system, on experiment was carried out at a commercial farm, of Paraná State, from July 2004 up to April 2005. A completely randomized block design, with four treatments, corresponding to different supplementation levels, with three replicates was applied. Treatments were pastures supplemented with 20%, 45%, 65% and 100% of supplementation (total diet calculated to give maintenance and milk production of 28kg/cow per day). The experimental area contained 32.4 hectares, being 22.4 hectares used during winter, composed of a mixture of annual ryegrass (Lolium multiflorum L.) and black oat (Avena strigosa Schreb), divided into twelve paddocks. During summer an area of 10 hectares was used, with Kikuyo (Pennisetum clandestinum) also divided in 12 paddocks. Three Holstein and one Jersey cows were used in each experimental unit as testers animals. The grazing system was continuous, with variable stocking. Put-and-take animals were used to control ward height, maintained around 20cm. Individual milk production was evaluated twice a week and percentage of fat, protein and somatic cell count were evaluated weekly. The economic analysis was proceeded using the methodology proposed by the Milk Cost Follow Up System of Paraná State. During the evaluation period, treatment 1 with 20% of supplementation showed the best results, with a total operational cost of R$ 0.4635 liter-1 and net income of R$ 0.13 liter-1.

Remote sensing offers the potential to spatially map forest cover quickly and reliably for inventory purposes. We developed a new image analysis approach using an integrated methodology of “object-based” image classification techniques and field-based measurements to quantify forest cover in a degraded dry forest ecosystem on the leeward side of the Island of Hawaii. This new approach explicitly recognized the transitional areas between tree crowns and tree shades (tree shadows) as a unique class and fully utilized them for the quantification of canopy cover. Object-oriented classification of Ikonos-2 satellite images allowed delineation of tree shades and crowns and the transitional areas between them from objects with similar reflectance and size that were surrounding the trees. These included patches of fountain (Pennisetum setaceum) and kikuyu (Pennisetum clandestinum) grass, lava outcrops and lava–grass mixtures. Crown-shade transitions were clearly differentiated in spite of their wide range of spectral values and reflectance similarities with areas of lava–grass mixture. Segments representing tree shades and dark lava outcrops were also classified into their respective classes even if they were contiguous. The image estimates of canopy cover using the tree shade plus transition classes were linearly related with field estimates of canopy cover (R2 = 0.86 and slope = 0.976). Based on this relationship, dry forest cover throughout the 2627-ha area was estimated at 7.7 ± 1.9%. An immediate application of this new approach is to select and delineate areas with higher canopy cover in order to concentrate ecological restoration and conservation efforts.

The objective of this work was to evaluate the intake (I) of all Buddleia skutchii foliage (BSF), collected from three different sites (places: A, B and C) in feeding sheep (phase 1), and in combination with Pennisetum clandestinum (Pc) (phase 2). Trials of feed intake, in vivo dry matter digestibility (IVDMD), and digestibilities of crude protein (CP), acid detergent fiber (ADF), neutral detergent fiber (NDF), and nitrogen balance were carried out during phase 1. Diet was given to nine Creole male lambs of 23(±3) kg body weight (BW), located in individual metabolism crates. During phase 2, four treatments were evaluated (T1 = 100% Pc, T2 = 20% BSF + 80% Pc, T3 = 40% BSF + 60% Pc and T4 = 60% BSF + 40% Pc) in a 4 × 4 Latin square design, using four ruminal cannulated Creole male rams of 50 ± 2 kg BW and remained in individual metabolism crates. In vivo digestibility (DM, CP and gross energy (GE)) and kinetics of in situ disappearance of DM were evaluated. The results in phase 1 indicated that BSF from Site B had relatively higher CP (14.9%), ADF (50.6%) content and nitrogen retention (1.93 g d−1). On the other hand, the lambs showed intake levels of 376.29 g d−1 DM, 56.21 g d−1 CP, 206.24 g d−1 ADF and 1418.21 kcal gross energy (P > 0.05); and digestibilities of 54.23% DM, 47.17% CP and 39.31% NDF. Therefore, BSF from Site B was selected for the second phase of this work as the best result. We observed that the nutrition quality of the diets was higher as a result of increasing BSF concentration in the diet. When sheep were fed on 40% BSF–60% Pc, DM intake levels of 900.6 g d−1, and DM, CP and GE digestibility of 70.0, 52.82 and 55.1%, respectively, were observed. There were not significant differences among diets, and in situ disappearance, Kd and Kp, but the diet with 60% of BSF presented higher ruminal digestibility (42.3%). The results allowed to validate the local knowledge on BSF as a promising forage species, and showed that BSF should be incorporated in a sheep production system.

Kikuyu grass, Pennisetum clandestinum Hochst. ex Chiov., is an important pasture species in many subtropical areas. Infestations of yellow sugarcane aphid (YSA), Sipha flava (Forbes) (Homoptera: Aphididae), have reduced kikuyu forage production in Hawaii. A novel method was developed to screen cultivars of kikuyu, and species of other forage and turf grasses for resistance to YSA. Kikuyu germplasm differed significantly in response to YSA with certain kikuyu hybrids more resistant to YSA than the common cultivar. However, even the kikuyu cultivars with the lowest damage ratings were considered only to be moderately resistant to YSA. Other forage grass species differed significantly in YSA damage, with Pacific fountain [Pennisetum macrostachys (Brongn.) Trin.], dallis (Paspalum dilatatum Poir.), torpedo (Panicum repens L.), tall fescue (Festuca arundinacea Schreb.), signal [Urochloa brizantha (Hochst. ex A. Rich.) R.D. Webster, formerly known as Brachiaria decumbens], bahia (Paspalum notatum Flugge), small buffalo (Panicum coloratum L.), velvet (Holcus lanatus L.), and switch (Panicum virgatum L.) grasses considered to be resistant to YSA. Turf grass species also differed significantly in YSA injury, with seashore paspalum (Paspalum vaginatum Sw.), St. Augustine [Stenotaphrum secundatum (Walter) Kuntze], and Japanese lawn (Zoysia japonica Steud.) grasses evaluated as resistant. Reduction of pasture forage by YSA could be ameliorated either by utilization of moderately tolerant kikuyu hybrids or resistant forage grass species.

In Hawaii, infestations of yellow sugarcane aphid (YSA), Sipha flava (Forbes) (Homoptera: Aphididae) reduced growth of the forage grass, kikuyu (Pennisetum clandestinum Hochst. ex Chiov). To determine the effects of nitrogen (N) and potassium (K) on tolerance of kikuyu grass to YSA, cuttings of eight and five cultivars were grown in the greenhouse using nutrient solutions in two separate trials, respectively. The first trial was conducted during the summer of 1991 and the second during the winter of 1993. In both trials, kikuyu was grown at three N levels (0.05, 0.5 and 3.0 mM) and four K levels (0.05, 0.5 1.0 and 3.0 mM), with one cultivar comprising a block. Prior to exposure to aphids, representative plants were harvested, and shoots were analyzed for foliar nutrients. Then, plants were confined with aphids and rated visually for YSA injury. Dry matter yields and foliar N concentration increased significantly with increasing N fertilization in both trials. In the first trial, there was a significant interaction between N and K levels, in which the greatest increases of shoot and root dry matter with increasing N levels were found at the highest K level. In the second trial, K fertilization had no effect on dry weight of shoots. In both trials, foliar K concentration increased significantly with increasing K levels. Damage due to YSA tended to increase with increasing N levels, although it was unaffected by K fertilization in both trials. Thus, fertilization with increasing N resulted in greater kikuyu dry matter production, but it also tended to increase the damage caused by YSA feeding.

The objective of this study was to quantify the differences in the nutritive value over 4 seasons, of 7 C 3 temperate grasses, 2 C 4 tropical grasses and 11 clover species used as forages for dairy cows. The nutritive value was assessed in terms of nutrient content and the availability of effective rumen degradable protein, rumen by pass protein, metabolisable protein (MP) and fermentable metabolisable energy. All species were grown in plots as monocultures under conditions of non limiting nutrients and moisture and harvested by mechanical means. All species had a high crude protein content and this resulted in a high effective rumen degradable protein: fermentable metabolisable energy ratio varying from 15, for cowpeas ( Vigna unguiculata ) to 29 for birdsfoot clover ( Lotus corniculatus ), and all were above the ratio of 11 required for optimal microbial protein synthesis in the rumen of dairy cows. The calculated availability of MP varied from 105 g/kg dry matter (DM) for cowpeas to 173 g/kg DM for berseem clover ( Trifolium alexandrinum ) indicating that all forages would be able to meet the requirements of dairy cows producing up to 30 L/milk/day, provided they were able to consume over 19 kg DM of forage/cow/day. Grasses had much higher hemicellulose (neutral detergent fibre minus acid detergent fibre) content than legumes. Kikuyu ( Pennisetum clandestinum ), a C 4 grass, had a higher proportion of hemicellulose content than the C 3 temperate grasses. Perennial ryegrass ( Lolium perenne ) and kikuyu had a similar metabolisable energy (ME) density (9.9 MJ/kg DM) in summer. The mean ME density of perennial ryegrass, prairie grass ( Bromus wildinowii ) and short rotation ryegrass ( Lolium multiflorum ) winter was similar at 10.6 MJ/kg DM and slightly higher than cocksfoot ( Dactylus glomeratus ), phalaris ( Phalaris tuberosa ) and fescue ( Fescue arundunicea ) which had a mean ME density of 10 MJ/kg DM. All forages grown were able to satisfy MP and ME requirements of dairy cows producing up to 30 L milk/cow/day, provided they were able to consume sufficient forage to achieve this level of production.

Summary Warm-season grasses and legumes have the potential to provide forage throughout the Mediterranean summer when there are high temperatures and low rainfall and when cool-season grasses become less productive. Twenty-nine non-native, warm-season pasture species (twenty-three grasses and six legumes) were assessed for their adaptability to the coastal plain of southern Italy in terms of their productivity and nutritional quality. The investigated species were compared with two reference species widely used in a Mediterranean environment: a grass (Festuca arundinacea) and a legume (Medicago sativa). The species differed in their phenological and biological characteristics, i.e. start of vegetative resumption, first flowering and cold resistance, from each other and from the control species. From the second year after establishment, warm-season perennial grasses had high dry-matter (DM) yields and, in many cases, a more than adequate nutritional quality. As for legumes, the control, M. sativa gave the best results in all the investigated characters. Among the grasses, seven species (Chloris gayana, Eragrostis curvula, Panicum coloratum, Paspalum dilatatum, Pennisetum clandestinum, Sorghum almum, Sorghum spp. hybrid) had DM yields greater than the control species and had their maximum growth during the hottest period of the year, when F. arundinacea, the control grass species, was dormant. Eragrostis curvula had the highest annual DM yield (21·1 t ha−1) and P. clandestinum provided the best combination of agronomic and yield characteristics which were similar to those of M. sativa. The seven above-mentioned species have the potential to supply hay or grazing and contribute to broadening and stabilizing the forage production calendar in Mediterranean-type environments.

Objective. To evaluate the effect of Kikuyu grass (Pennisetum clandestinum) harvested at two different ages and three forage: concentrate supplement ratios (F/C) on methane (CH4) production, dry matter digestibility (DMD), and fermentation profile using the in vitro gas production technique. Materials and methods. six treatments, resulting from the combination of pasture age (30 or 60 days) and F/C (100/0, 75/25, or 50/50) were evaluated using a 2x3 factorial design. The response variables were measured 6, 12, 24 and 48 hours after incubation. A repeated-measure over time design was used to analyze the data, and differences between means were determined with the LSMEANS procedure of SAS. Results. the youngest grass (30 days) was more digestible, produced less CH4 per gram of digestible dry matter (dDM) and more total volatile fatty acids (VFA) compared to the oldest grass (60 days; p 0.05). Conclusions. under in vitro conditions and pH close to neutrality, the older grass reduces DMD and increases CH4 production per gram of dDM, while a F/C reduction increases DMD and CH4 production per gram of dDM, which differs with reports conducted in vivo.

Para determinar la mezcla de abonos, natural y sintético, que optimicen la calidad de un suelo agrícola, se realizó el presente trabajo en Pampa del Arco, Ayacucho, con suelo agrícola en descanso (por cinco años) bajo cobertura de Pennisetum clandestinum. La unidad experimental consistió en baldes plásticos para 20 kg de suelo con cultivo de tomate. Se utilizó el diseño 03 de julio para dos factores (a: abono natural, compost; b: fertilizantes sintéticos, NPK). Se evaluaron la calidad del suelo y salud del cultivo. Los resultados encontrados permiten concluir lo siguiente: 1. La calidad del suelo sufre cambios significativos según la mezcla de abonos, siendo más perjudiciales las que llevan altos niveles de abono sintético; contrariamente el compost contribuye a mantener una adecuada tasa de infiltración del agua en el perfil del suelo. La aplicación de abono sintético, sin compost, afecta la actividad microbiana del suelo; 2. El menor impacto negativo sobre la infiltración del agua en el perfil del suelo se consigue aplicando mezclas de un mínimo de 5 t.ha-1 de compost con 80-90-70 kg.ha-1 de NPK, o 7.5 t.ha-1 de compost con 160-180-140 kg.ha-1 de NPK; 3. Los modelos que predicen la influencia del abono orgánico (compost) y del abono sintético en la calidad del suelo y salud del cultivo son: Y = 22.74 + 2.0949X1 - 4.3154X2 + 0.8430X1² - 0.5648X2² + 0,2771X1X2, para la infiltración del agua; Y = 805.9 + 35.98462X1 + 52.72179X2 + 2.20291X1² - 10.23337X2² - 9.05208X1X2, para el rendimiento de tomate., To determine the mix of fertilizers, natural and synthetic, that optimize the quality of an agricultural soil, the present work was carried out in Pampa del Arco, Ayacucho, with agricultural soil at rest (for five years) under cover of Pennisetum clandestinum. The experimental unit consisted of plastic buckets for 20 kg of soil with tomato cultivation. The July 3 design was used for two factors (a: natural fertilizer, compost; b: synthetic fertilizers, NPK). Soil quality and crop health were evaluated. The results found allow us to conclude the following: 1. The quality of the soil undergoes significant changes according to the mix of fertilizers, being more damaging those that carry high levels of synthetic fertilizer; On the contrary, compost contributes to maintaining an adequate rate of water infiltration in the soil profile. The application of synthetic compost, without compost, affects the microbial activity of the soil; 2. The least negative impact on water infiltration in the soil profile is achieved by applying mixtures of a minimum of 5 t.ha-1 of compost with 80-90-70 kg.ha-1 of NPK, or 7.5 t. ha-1 of compost with 160-180-140 kg.ha-1 of NPK; 3. The models that predict the influence of organic manure (compost) and synthetic manure on soil quality and crop health are: Y = 22.74 + 2.0949X1 - 4.3154X2 + 0.8430X1² - 0.5648X2² + 0.2771X1X2, for water infiltration; Y = 805.9 + 35.98462X1 + 52.72179X2 + 2.20291X1² - 10.23337X2² - 9.05208X1X2, for tomato yield.

La adecuada estimación del consumo de nutrientes de animales en pastoreo permite identificar estrategias para aumentar la sustentabilidad productiva y ambiental de la producción ganadera. En este estudio, se estimó el consumo, digestibilidad y excreción de nutrientes de novillos de diversos cruces, pastoreando en praderas de kikuyo (Pennisetum clandestinum), en una finca de trópico de altura y distribuidos en dos grupos: el grupo SS (peso inicial: 380,0±19,97 kg) que se encontraba únicamente en pastoreo y el grupo CS (peso inicial: 374,7±20,81 kg), que además del pastoreo, recibió 0,55 kg/día de un suplemento de maíz, melaza y grasa animal (51, 12 y 37%, respectivamente). Los animales CS pastoreaban en 2,5 ha y los SS en 3,2 ha. El consumo de materia seca (CMS) y la producción de heces fueron determinados mediante la técnica de alcanos. El CMS fue de 7,97 y 7.19 kg de MS, 2,13±0,07 y 1,89±0,027 como porcentaje del peso vivo o 93,59 y 83,54 g por kilogramo de peso metabólico en los animales CS y SS, respectivamente. La excreción fecal fue de 3,40±0,25 y 3,29±0,51 kg/día, siendo la digestibilidad de 56,2 y 54,7% para el grupo CS y SS, respectivamente. Hubo un consumo alto de PC y un consumo intermedio de FDN, FDA y cenizas y el consumo de calcio y fósforo fue bajo. Se determina para mejorar los parámetros zootécnicos de la ceba de novillos en praderas de P. clandestinum es necesario identifi car una fuente energética adecuada para mejorar la relación energía: proteína de la dieta. Adequate estimates of nutrient intake by grazing animals are necessary to increase production and environmental sustainability of livestock production. In this study, intake, digestibility and nutrient excretion by steers of various crosses grazing on Kikuyu grass (Pennisetum clandestinum) on a tropical highland farm were estimated. Animals were distributed into two grazing groups: Animals in one group (NS: 380.0±19.97 kg initial weight) were only grazing, whereas those of the other group (S: 374.7±20.81 kg initial weight) also received 0.55 kg/ day of a corn, molasses and tallow (51, 12 and 37%, respectively) supplement. Supplemented animals grazed in 2.5 ha whereas NS animals grazed in 3.2 ha. Both intake and fecal output were determined by the alkane technique. Daily dry matter intake in the S animals, was 2.13±0.07 of liveweight, 93.59 g per kg of metabolic weight (MW) and 7.97 kg of DM, while that of NS animals was y 1.89±0.027 of liveweight, 83.54 g per kg of PM and 7.19 kg of DM. Fecal excretion was 3.40±0.25 and 3.29±0.51 % kg/ day, thus digestibility was 56.2 and 54.7 % for S and NS groups, respectively. High crude protein intake, intermediate intakes of NDF, ADF and ash and low intakes of calcium and phosphorus were observed. It was determined that to improve zootechnical parameters when fattening steers on kikuyu pastures, it is necessary to identify a suitable energy source to improve the energy: protein ratio of the diet.

En Colombia, la producción de carne bovina tradicionalmente se realiza en el trópico bajo, mientras que en el trópico de altura, los sistemas ganaderos predominantes son de lechería especializada. Las gramíneas de trópico alto son de mayor valor nutricional que las de trópico bajo, aunque pueden presentar un exceso de proteína, por lo cual una estrategia de suplementación debe basarse en la inclusión de materias primas energéticas. Al analizar la oferta de nutrientes en el pasto kikuyo (Pennisetum clandestinum) se observan altos contenidos de proteína (20.6%) y baja disponibilidad de energía (2.31 Mcal EM/ kg). Así, el presente estudio se realizó con el propósito de evaluar la producción de carne bovina en condiciones de trópico de altura (Santa Rosa de Osos, Antioquia). Durante 122 días se evaluó el crecimiento de 18 novillos de diversos cruces, que pastoreaban en dos grupos en praderas de kikuyo hasta alcanzar el peso de beneficio (420 kg). El primer grupo (peso inicial 316±370 kg) recibió 0.55 kg/día de un suplemento energético a base de maíz, melaza y sebo (51%, 12% y 37%, respectivamente), mientras el segundo grupo (peso inicial 322,8±27.8 kg) se encontraba sólo en pastoreo. Los animales suplementados (CS) pastoreaban en 2.5 ha y los no suplementados (SS) en 3.2 ha. Hubo una ganancia total de 78.8 y 73.3 kg de peso/novillo durante todo el período, equivalentes a ganar 646 y 601 gr/animal/día y a producir 848.5 y 617.1 kg de carne/ha/año en el sistema CS y SS, respectivamente. Cebar novillos en trópico de altura puede ser una actividad productiva exitosa, pero es necesario identificar, tanto el nivel de inclusión, como la fuente energética adecuada para mejorar la relación energía:proteína en la dieta de animales pastoreando P. clandestinum. In Colombia, beef cattle are traditionally raised in lowland areas, whereas dairies are the predominant production systems in the highland areas. Highland grasses are of greater nutritional value (protein content and digestibility) than lowland grasses, but may have an excess of protein, so supplementation strategies should be based on the inclusion of energy feeds. After determining that the protein content in kikuyu grass (Pennisetum clandestinum) is very high (20.6%) and that the availability of energy (2.31 Mcal ME/ kg DM) is the most limiting dietary factor, a study to evaluate the production of beef under tropical highland conditions was carried out in santa Rosa de Osos, Antioquia. in this study, the growth of 18 steers of different crosses, homogeneously distributed in two groups grazing on Kikuyu pastures was assessed for 122 days until animals reached harvest weight (420 kg). The first group (316 ± 37.0 kg initial live weight) received 0.55 kg/day of a corn, molasses and tallow (51, 12, and 37%, respectively) energy supplement, while the second group (322.8 ± 27.8 kg initial live weight) was only grazing. supplemented animals (s) grazed in 2.5 ha, whereas non-supplemented animals (Ns) grazed in 3.2 ha. Total weight gain for the entire period was 78.8 and 73.3 kg for s and Ns animals, respectively. Fattening steers in tropic highlands can be a successful production activity, but it is necessary to identify both an appropriate energy source and its level of inclusion to improve the protein:energy ratio in the diet of beef steers grazing in P. clandestinum pastures.

The use of plant growth regulators (PGRs) and biostimulants to enhance phytoextraction is gaining popularity in phytoremediation technology. This study investigated the stimulatory effects of smoke-water (SW), a smoke-derived compound karrikinolide (KAR1) and other known plant growth regulators (PGRs) [gibberellic acid (GA3), kinetin (Kin) and indole-3-butyric acid (IBA)] to enhance the phytoextraction potential of Pennisetum clandestinum. Pennisetum clandestinum seedlings were grown for 10 weeks in vermiculite using Hoagland's nutrient solution and were treated with cadmium (Cd) (2, 5, and 10 mg L(-1)) and SW, KAR1 and PGRs. KAR1 exhibited positive effects on shoot and root dry weight (140 and 137 mg respectively) at the highest concentration of Cd (10 mg L(-1)) compared to all the other treatments. KAR1 and SW treatments used in the present study significantly improved the phytoextraction potential of P. clandestinum (602 and 575 mg kg(-1) respectively) compared to the other tested PGRs. This is the first report on the use of SW and KAR1 to enhance phytoremediation potential in P. clandestinum. Further studies are needed to elucidate the exact mechanisms of smoke constituents involved in phytoextraction potential of plant species.

Article first published online: 10 MAR 2014.--11 páginas, 6 tablas., The effects of three treatments of fibrolytic enzymes (cellulase from Trichoderma longibrachiatum (CEL), xylanase from rumen micro-organisms (XYL) and a 1:1 mixture of CEL and XYL (MIX) on the in vitro fermentation of two samples of Pennisetum clandestinum (P1 and P2), two samples of Dichanthium aristatum (D1 and D2) and one sample of each Acacia decurrens and Acacia mangium (A1 and A2) were investigated. The first experiment compared the effects of two methods of applying the enzymes to forages, either at the time of incubation or 24 h before, on the in vitro gas production. In general, the 24 h pre-treatment resulted in higher values of gas production rate, and this application method was chosen for a second study investigating the effects of enzymes on chemical composition and in vitro fermentation of forages. The pre-treatment with CEL for 24 h reduced (p < 0.05) the content of neutral detergent fibre (NDF) of P1, P2, D1 and D2, and that of MIX reduced the NDF content of P1 and D1, but XYL had no effect on any forage. The CEL treatment increased (p < 0.05) total volatile fatty acid (VFA) production for all forages (ranging from 8.6% to 22.7%), but in general, no effects of MIX and XYL were observed. For both P. clandestinum samples, CEL treatment reduced (p < 0.05) the molar proportion of acetate and increased (p < 0.05) that of butyrate, but only subtle changes in VFA profile were observed for the rest of forages. Under the conditions of the present experiment, the treatment of tropical forages with CEL stimulated their in vitro ruminal fermentation, but XYL did not produce any positive effect. These results showed clearly that effectiveness of enzymes varied with the incubated forage and further study is warranted to investigate specific, optimal enzyme-substrate combinations., The authors wish to acknowledge the financial support received from the Junta de Castilla y Leon (Pro- ject LE040A05), MICINN (Project AGL2008-04707- C02-02) and the MAE-AECID (Project A/4951/06). A. Dıaz and L.A. Giraldo gratefully acknowledge receipt of grants from the Spanish AECID and the Fundacion Carolina respectively. M.L. Tejido gratefully acknowledges a postdoctoral contract from Spanish CSIC (JAE-doc program).

Distintas especies forrajeras, como kikuyo (Penninsetum clandestinum) y rye grass anual (Lolium multiflorum), están ampliamente difundidas en la sierra ecuatoriana. Si bien pueden ser una solución al problema de la alimentación que enfrentan los productores, por ser una fuente nutricional de fácil acceso, en la actualidad estos recursos se están subutilizando al no considerarse su verdadero aporte nutricional. El objetivo de este estudio fue determinar el valor de la energía, para ganado de carne y leche, del kikuyo y el rye grass perenne (Lolium perenne) a diferentes edades de corte. Cuenca

The new monotypic genus Kikuyuochloa, based on Pennisetum clandestinum, is erected. Contrary to the common view in Pennisetum clandestinum (Kikuyuochloa clandestina) 1–4(–6) unispiculate inflorescences each subtended by bristles are grouped in one cluster, the cluster representing the real inflorescence unit homologous to the partial inflorescence of Pennisetum. A basal bristled involucrum is absent in Kikuyuochloa; the bristle configuration beneath the individual spikelets of Kikuyuochloa is not comparable to the bristled involucrum of Pennisetum. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) Kikuyuochloa, genus novum (Poaceae: Paniceae) Fur Pennisetum clandestinum wird die neue Gattung Kikuyuochloa beschrieben. Entgegen allgemeiner Ansicht ist die Gruppe der jeweils von basalen Borsten umgebenen 1–4(–6) einahrigen Blutenstande (Infloreszenzen) des Pennisetum clandestinum (Kikuyuochloa clandestina) homolog dem Teilblutenstand (Partial-Infloreszenz) des Pennisetum. Eine grundstandige Borstenhulle (Involucrum) fehlt der Kikuyuochloa; die Anordnung der Borsten der einzelnen Ahrchen bei Kikuyuochloa ist nicht vergleichbar derjenigen der Borstenhulle des Teilblutenstandes bei Pennisetum.

In this study, the effect of increasing the proportion of concentrate in the diet, on efficiency of feed utilisation, was determined when Holstein–Friesian cows grazed short-rotation ryegrass (Lolium multiflorum) or kikuyu (Pennisetum clandestinum) pastures. The concentrates were energy-dense dairy pellets fed twice-a-day at milking and the roughage component was lucerne hay and the pasture. When cows grazed ryegrass, there was no effect on animal performance as the proportion of concentrate in the diet increased from 0.23 to 0.35 (4.75 to 7.50 kg concentrate/cow/day). The substitution rate of concentrates for pasture for the first 1.57 kg concentrate/cow/day fed was 0.58 but rose to 1.18 for the next 1.28 kg concentrate/cow/day. When cows grazed kikuyu, there was also no effect of increasing the proportion of concentrate in the diet on total dry matter intake (DMI) or milk production. However, there was a substantial increase in the in vivo digestibility of whole diet, pasture and acid detergent fibre (ADF) was observed when the proportion of concentrate in the diet increased from 0.08 to 0.25. However, there was a marked decline in pasture digestibility (72% to 64%), and more so in ADF digestibility (61.3% to 48.4%), as the proportion of concentrate in the diet increased further to 0.29 (5.52 kg/cow/day). The intake of kikuyu, when determined by difference between pre- and post-grazing pasture mass, was substantially underestimated compared to the use of the n-alkane technique, and this discrepancy increased as the pasture on offer increased. On both pasture types, the neutral detergent fibre intake, as a % of bodyweight varying from 1.6% to 2.2% for kikuyu and 1.5% to 1.6% for ryegrass was far above the values claimed of 1.2% to restrict intake. The results of this study highlight the limits to the amount of concentrate that can be fed on a typical Australian dairy farm where concentrates can only be fed twice-a-day at milking. The results also provide a more appropriate benchmark for fibre limitation in the ration when cows graze pasture, particularly poorer quality tropical grasses, and this value is well above that found in more intense feeding situations.

Pennisetum clandestinum (Kikuyu grass, Graminae) is an active Si accumulator growing in altitude in Kenya. To verify the influence of Si on mineral uptake, P. clandestinum was cultivated in two different substrata both with low silicon levels. P. clandestinum growing in organic-rich soils (43.3% organic matter) contained much more Cu, Mn and Zn but less Si in the whole plant and Fe in the roots than species growing in a sandy matrix, indicating that Si does not interfere with the uptake of such nutrients. In 90% of the cases, roots have the highest average values regardless of the type of culture considered. Plants in sand substrates (82.2% sand) exhibited much more Si (particularly roots) than plants in organic-rich soils, despite the high carbonate content of both matrices and the acid pH used in the nutrient solution. The more Si is present in shoots and roots, the less P is detected. N/P ratios of shoots of sand culture confirm a nutrient limitation of P. Shoot biomass in organic-rich soils w...

Yearling Hereford and Holstein-Friesian heifers were grazed on kikuyu pasture during summer and the intake and apparent digestibility were estimated using the n-alkane procedure. There were eight animals of each breed. The trial was conducted during the last two weeks of January at the Cedara Research Station in the KwaZulu-Natal mist-belt of South Africa. The animals were on a continuous grazing regime at a stocking rate of four heifers per hectare. Herbage availability was estimated using a disc meter at about 1545 kg dry matter (DM) per hectare. Crude protein (CP), acid detergent fibre (ADF) and neutral detergent fibre (NDF) in hand plucked samples were estimated at 179 g/kg DM, 332 g/kg DM and 667 g/kg DM, respectively. The Herefords had a 22% higher intake (P 0.05), which was on average 0.58.

The turf grass Pennisetum clandestinum Hochst. (kikuyu grass) is one of the candidate plants for utilization and reclamation of salinized areas. The capability of kikuyu grass to grow under saline conditions was tested during 6 months, under various irrigation treatments (tap water control, 80‐mM, 150‐mM, 200‐mM, 240‐mM NaCl). Plant biomass production was visibly affected only at NaCl concentrations greater than 150‐mM NaCl. Plant growth and plant regeneration capability in the 200‐ and 240‐mM NaCl treatments gradually decreased as the experiment progressed in time. The photosynthetic potential of the plants remained unchanged and was neither affected by the treatment nor with time. Proline content of leaves as well as the content of Na+ and Cl− increased with increasing salinity stress. Apparently, kikuyu grass can withstand moderate concentrations of NaCl for prolonged periods and under repeated mowing. Thus, this grass can be used as a potential ground cover and as fodder grass in saline habitats.

The response of introduced (Pennisetum clandestinum Hochst.) and native (Stipa aristiglumis F. Muell., Themeda australis (R. Br.) Stapf, Danthonia spp. (L.) grasses to the herbicide atrazine was studied in plants with the potential for use in vegetated filters (biofilters) designed to reduce chemical loads in agricultural runoff. The response was detected by photosynthetic inhibition using leaf chlorophyll fluorescence. With continuous short-term (14 days) dosing with atrazine in sand culture, P. clandestinum showed the greatest tolerance, regardless of the dose (20–500 μg/L). In a clay vertosol soil in the glasshouse, the four species were tolerant to longer-term (84 days) application of three successive doses of simulated run-on, each dose containing 100 μg/L atrazine, a concentration which is comparable to the highest reported in runoff from agricultural land in Australia. Even with a subsequent single atrazine dose at ∼ ∼5000 μg/L, established plants of the four species showed signs of quick recovery (7–21 days) to normal photosynthetic activity. In a field experiment with simulated run-on, applied to P. clandestinum pasture in sandy loam soil, repeated doses at concentrations up to 1000 μg/L gave no significant response; only a subsequent single dose of 5000 μg/L had significant effects, from which plants soon recovered. Although damage from atrazine can be demonstrated with continuous dosing in non-adsorbing media, in soil culture the tolerance of the four selected species to repeat doses of atrazine shows they may be used confidently for biofiltering purposes. P. clandestinum was especially tolerant.

Take-all, caused by the soil-borne pathogen Gaeumannomyces graminis var. tritici (Ggt), is a devastating root disease of wheat. As well as infected host residues from previous wheat crops, grass crop or weed species also play an important role in the carry-over of inoculum to the next wheat crop. However, the survival and spread of inoculum on different grasses differs considerably depending on their susceptibility to the pathogen. Using Triticum aestivum (wheat) and Avena sativa (oat) as susceptible and resistant standards, the susceptibility to Ggt of 24 grass species commonly found within wheat crops in New Zealand was examined in a simple laboratory assay. Of all the grass species evaluated, 83% were susceptible to Ggt with Bromus diandrus, Bromus willdenowii, Bromus inermis and Pennisetum clandestinum being highly susceptible, while Cynosurus cristatus, Cynodon dactylon and Paspalum dilatatum were highly resistant to the pathogen.

Solid-state 15N NMR spectroscopy was used to determine the chemical nature of nitrogen in 15N-enriched material from the roots and stems of wheat (Triticum aesitivum), field pea (Pisum sativum) and kikuyu grass (Pennisetum clandestinum) and from the roots, stems and leaves of a eucalyptus species (Eucalyptus globulus). Nitrogen-15 cross polarization (CP) spectra of the materials were all very similar, with 64–75% of total signal assigned to amide N. Spin counting analysis indicated that 37–80% of potential signal was accounted for in the CP spectra, and that NMR observability using the CP technique (N obs -CP) was higher for stems and leaves than for roots, and higher for wheat and eucalyptus than for peas and kikuyu. The 15N direct polarization (DP) spectra contained higher proportions of signal assigned to amine (up to 22%) and nitrate (up to 17%), and less assigned to amide N (50–72%) than the corresponding CP spectra. Spin counting analysis indicated that 68–93% of potential signal was accounted for in the DP spectra, confirming the DP technique to be more quantitatively reliable than CP.

Con el propósito de evaluar la calidad nutricional en ensilajes de follaje de árboles como fuentes forrajeras altemativas para ganado lechero se realizó una simulación productiva y económica de un hato lechero de la Sabana de Bogotá. Para la simulación se utilizó la información del hato lechero del C. I. Tibaitatá aplicando el modelo Comell Net Carbohydrate and Protein System (CNCPS). La base alimenticia del hato fue pastoreo libre de Pennisetum clanilestinum (Kikuyo) suplementado con seis tipos diferentes de ensilaje (T1 a T6) a base de follaje de Sambucus peruoiana, Acacia Decurrens y Avena sativa, tratados con ácido fórmico al 85%, extracto enzimático y el producto comercial Kem Lac®*. Las dietas de ensilajes tratados con extracto enzimático presentaron el mejor desempeño productivo y económico en la simulación, así: (T3) 1,8 L/día e ingreso neto diario de $7.216 por vaca; (T1) 18 L/día e ingreso neto diario de $7.623 por vaca; y (T6) 1,8.2 L/día e ingreso neto diario de $ 6.146 por vaca. Cuando se adicionó melaza de caña, la respuesta en T3 fue de 229 L/día y $ 9.548 de ingreso neto vaca/día, con una tasa de retomo marginal de 65.5%. E sta respuestas e atribuyó a la mayor eficiencia en la utilización de los nutrientes y al adecuado sincronismo de éstos en el rumen, que se reflejó en un incremento de la proteína de origen microbial y en un equilibrio adecuado de péptidos ruminales estimados en la simulación. * Kem Lac®: Kemin lrdustries, Inc. 2100 Maury St., Box 70. Des Moines, AL USA. 50031-0070.515/226-2111.

The effects of agricultural land use [kikuyu pasture (Pennisetum clandestinum), annual ryegrass pasture (Lolium multiflorum). maize (Zea mays), preharvest burnt sugarcane (Saccharum spp.) and undisturbed native grassland] on the catabolic diversity of soil microbial communities were determined using Biolog Grain Negative (GN) microplates or a substrate-induced respiration (SIR) technique. These techniques were also used to determine catabolic diversity in sugarcane soil under long-term preharvest burning or under green cane harvesting with retention of a trash mulch (with or without annual fertilizer additions). Principal component analysis (PCA) of Biolog data revealed large differences in catabolic capability of soil microbial communities between burnt sugarcane, annually tilled (annual ryegrass and maize) and non-tilled grass (kikuyu pasture and native grassland) land uses. For SIR data, differences in catabolic capability existed between all land uses. PCA of Biolog data showed large differences in catabolic capability between sugarcane soil under trashing and preharvest burning but there was little effect of fertilizer applications. However, for SIR data, differences due to both trashing versus burning and fertilizer versus no fertilizer were evident. For Biolog data values for Shannon's diversity index followed the order: kikuyu pasture = native Grassland = ryearass pasture > maize = burnt sugarcane and trashed sugarcane had higher values than burnt sugarcane. For SIR data, substrate richness was similar between treatments and catabolic evenness followed the order: native Grassland > kikuyu pasture > ryegrass pasture > maize = burnt sugarcane and was greater for trashed than burnt sugarcane. It was concluded that the SIR method was more effective at separating treatments with broadly similar land uses and managements than the Biolog method. In general, land uses and managements that increased soil organic matter tended to increase catabolic diversity. (c) 2004 Elsevier B.V. All rights reserved.

A series of in vitro incubations with kikuyu grass (Pennisetum clandestinum), lucerne and six legumes containing condensed tannins (CT) were undertaken to evaluate this technique against in vivo trials in New Zealand, measuring methane emissions. Published trials have demonstrated a reduction in methane emissions associated with CT and in one instance from kikuyu. The incubations used fresh minced forage (equivalent to 0.5 g dry matter (DM)) and were carried out in 50 ml sealed bottles containing buffer and rumen inoculum. Gas was sampled through a septum to monitor volume and composition throughout the 24h incubation. Incubation for 24 h resulted in 2.4-6.6 % conversion of DM to methane, and suggested CT concentrations below about 8% of the DM can reduce methane production without inhibiting fermentation rate. Higher concentrations of CT (> 8%) were associated with a lower rate of digestion. In common with in vivo trials, CT concentration in forage DM was inversely related to methane (adjusted R2 = 0.49; P = 0.01) and volatile fatty acid (adjusted R2=0.86; P