Popondetta, Papua New Guinea
Popondetta, Papua New Guinea

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Gitau C.W.,Charles Sturt University | Gurr G.M.,Charles Sturt University | Dewhurst C.F.,PNG Oil Palm Research Association | Mitchell A.,College Street | And 3 more authors.
Annals of Applied Biology | Year: 2011

Finschhafen disorder (FD) affects coconut and oil palms in Papua New Guinea (PNG). It is characterised by yellow-bronzing of fronds which begins at the tips and progresses towards the petiole. Although the planthopper Zophiuma lobulata (Hemiptera: Lophopidae) has been posited as a cause of FD, the basis of the relationship has not been established. Studies conducted previously on FD predate the availability of DNA-based techniques to test for the involvement of plant pathogens such as phytoplasmas that cause yellows-type diseases in many plant taxa and are transmitted by the order of insects to which Z. lobulata belongs. In this study, polymerase chain reaction (PCR) assays found no evidence of phytoplasmas or bacteria-like organisms (BLOs) in tissues of coconut and oil palm symptomatic for FD and from Z. lobulata feeding on these plants. Further studies involved releasing Z. lobulata adults and nymphs onto caged, potted coconut and oil palms and onto palm fronds enclosed in mesh sleeves. In both experiments, chlorotic symptoms on the palms were observed in the presence of Z. lobulata. Insect-free control palms did not exhibit chlorotic symptoms of FD. In the frond sleeve experiment, only the fronds where Z. lobulata fed developed chlorosis indicating that the disorder is not systemic. Unlike most yellows-type diseases associated with Hemiptera, this study indicates that FD is because of a direct feeding effect on palms by Z. lobulata rather than transmission of a pathogen. © 2010 Association of Applied Biologists.


Gitau C.W.,Charles Sturt University | Fletcher M.J.,Charles Sturt University | Fletcher M.J.,Orange Agricultural Institute | Mitchell A.,College Street | And 2 more authors.
Australian Journal of Entomology | Year: 2011

An examination of the five described species of the New Guinean genus Zophiuma Fennah (Hemiptera: Fulgoromorpha: Lophopidae), has confirmed that Zophiuma guineae (Lallemand) is a new synonym of Zophiuma pupillata (Stål) and that Zophiuma lobulata Ghauri is a new synonym of Zophiuma butawengi (Heller). The third species of the genus, Zophiuma doreyensis Distant, is known only from the male holotype. The morphology of the male genitalia and mitochondrial cytochrome oxidase subunit I (COI) gene sequences were used to compare Z. pupillata and Z. butawengi. Both the male genitalia and the COI sequences showed clear cut differences between the two species with little intraspecific variation in comparison to interspecific variation. Sequence data demonstrated that males collected with the distinctively coloured Z. pupillata females are the males of that species. Male genitalia of Z. pupillata are described and illustrated for the first time and a key for the discrimination of the three species of the genus is provided. © 2011 The Authors. Journal compilation © 2011 Australian Entomological Society.


Huber J.T.,Natural Resources Canada | Gitau C.W.,Charles Sturt University | Gurr G.M.,Charles Sturt University | Dewhurst C.F.,PNG Oil Palm Research Association | And 2 more authors.
Zootaxa | Year: 2011

Both sexes of Parastethynium maxwelli (Girault), a parasitoid of Zophiuma lobulata Ghauri eggs on coconut and oil palm in Papua New Guinea, are described and illustrated. The second known species in the genus Parastethynium, P. hirsutum Huber sp. n., from Indonesia (Sulawesi) is also described. The latter represents the first record from the Oriental region. The basic biology of P. maxwelli is presented. Mean progeny produced per female was 57 with a female proportion of 0.59. Mean egg to adult development time was 11 days, at 24.5°C-29.7°C and 72-93% relative humidity. Survival time of females and males fed on honey and water was longer compared to males and differed significantly with those provided with water only or nothing at all. Copyright © 2011 Magnolia Press.


Nelson P.N.,James Cook University | Webb M.J.,James Cook University | Banabas M.,PNG Oil Palm Research Association | Nake S.,PNG Oil Palm Research Association | And 4 more authors.
Plant and Soil | Year: 2014

Background and aims: Lateral tree-scale variability in plantations should be taken into account when scaling up from point samples, but appropriate methods for sampling and calculation have not been defined. Our aim was to define and evaluate such methods. Methods: We evaluated several existing and new methods, using data for throughfall, root biomass and soil respiration in mature oil palm plantations with equilateral triangular spacing. Results: Three ways of accounting for spatial variation within the repeating tree unit (a hexagon) were deduced. For visible patch patterns, patches can be delineated and sampled separately. For radial patterns, measurements can be made in radial transects or a triangular portion of the tree unit. For any type of pattern, including unknown patterns, a triangular sampling grid is appropriate. In the case studies examined, throughfall was 79 % of rainfall, with 95 % confidence limits being 62 and 96 % of rainfall. Root biomass and soil respiration, measured on a 35-point grid, varied by an order of magnitude. In zones with steep gradients in parameters, sampling density has a large influence on calculated mean values. Conclusions: The methods defined here provide a basis for representative sampling and calculation procedures in studies requiring scaling up from point sampling, but more efficient methods are needed. © 2013 Springer Science+Business Media Dordrecht.


Huth N.I.,CSIRO | Banabas M.,PNG Oil Palm Research Association | Nelson P.N.,James Cook University | Webb M.,CSIRO
Environmental Modelling and Software | Year: 2014

Oil palm has become one of the most important crops in the world with questions being raised about its economic and environmental sustainability. Agricultural systems models are regularly employed in studying sustainable crop management but no detailed model is currently available for oil palm systems.We developed a production systems model for oil palm within the Agricultural Production Systems Simulator (APSIM) framework and tested it using data across a range of environments within Papua New Guinea (PNG). The model captured key growth responses to climate and management. This demonstrates that modern modelling frameworks do allow for rapid model development for new agricultural systems.However, whilst application of the model is promising, the availability of key data is likely to restrict its use. Local soil and weather data are not available in adequate detail for many of the major oil palm production areas, although some methods exist to address this. © 2014.


Goodrick I.,James Cook University | Nelson P.N.,James Cook University | Nake S.,PNG Oil Palm Research Association | Webb M.J.,James Cook University | And 2 more authors.
Soil Research | Year: 2016

Soil carbon fluxes are highly variable in space and time under tree crops such as oil palm, and attempts to model such fluxes must incorporate an understanding of this variability. In this work, we measured soil CO2 emission, root biomass and pruned frond deposition rates and calculated carbon fluxes into and out of the soil in a mature (20-year-old, second planting cycle) oil palm plantation in Papua New Guinea. Tree-scale spatial variability in CO2 emission and root biomass was quantified by making measurements on a 35-point trapezoid grid covering the 38.5-m2 repeating unit of the plantation (n≤4 grids). In order to obtain an overall mean soil CO2 emission rate within 5% of the most accurate estimate, ≥24 measurement points were required. Soil CO2 emissions were spatially correlated with calculated carbon inputs (r2≤0.605, slope 1:1), but not with soil water content or temperature. However, outputs were higher than inputs at all locations, with a mean overall output of 7.24μmolm-2s-1 and input of 3.02μmolm-2s-1. Inputs related to fronds, roots and groundcover constituted 60%, 36% and 4% of estimated inputs, respectively. The spatial correlation of carbon inputs and outputs indicates that mineralisation rate is controlled mostly by the amount rather than the nature or input depth of the additions. The spatially uniform net carbon emission from soil may be due to inaccuracies in calculated fluxes (especially root-related inputs) or to non-biological emissions. © CSIRO 2016.


Nelson P.N.,James Cook University | Nelson P.N.,CIRAD - Agricultural Research for Development | Gabriel J.,James Cook University | Filer C.,Australian National University | And 5 more authors.
Conservation Letters | Year: 2014

An unprecedented increase in oil palm developments may be underway in Papua New Guinea (PNG) through controversial "special agricultural and business leases" (SABLs) covering over two million hectares. Oil palm development can create societal benefits, but doubt has been raised about whether the SABL developers intend establishing plantations. Here, we examine the development objectives of these proposals through an assessment of their land suitability, developer experience and capacity, and sociolegal constraints. Our review reveals 36 oil palm proposals with plantings planned for 948,000 ha, a sevenfold increase over the existing planted area in PNG. Based on our criteria, however, we estimate that only five plantations covering 181,700 ha might eventuate within the foreseeable future. We conclude that most of the developers are clearing forest with no intention of cultivating oil palm, and that a large-scale land grab is therefore occurring in PNG under the guise of oil palm development. © 2013 Wiley Periodicals, Inc.


Dewhurst C.F.,PNG Oil Palm Research Association | Tennent W.J.,Natural History Museum in London
Australian Entomologist | Year: 2011

This note confirms the presence of three butterfly species, Erionota thrax hasdrubal Fruhstorfer (Hesperiidae), Taenaris phorcas (Westwood) and Elymnias cybele holofernes (Butler) (Nymphalidae), feeding on oil palm (Elaeis guineensis) in West New Britain Province, Papua New Guinea. One of these is a well known agricultural pest of banana plants; the other two species do not appear to have been recorded previously from West New Britain.


Mudge A.M.,University of Queensland | Hamdani A.D.,University of Queensland | Hamdani A.D.,State Islamic University of Yogyakarta | Pilotti C.A.,PNG Oil Palm Research Association | Godwin I.D.,University of Queensland
Tropical Plant Biology | Year: 2016

Our aim was to assess parental and population genetic variability in a partially nested set of breeding populations from the breeding program at Dami Research Station (West New Britain, PNG). Twenty microsatellite markers were tested for their ability to characterize genetic variation in oil palm populations bred at Dami Research Station. One hundred and twenty six individuals, including 100 F1tenera hybrids of Dami Deli crossed with either AVROS, Ghana or AVROS/Ghana breeding lines were analysed. Eighteen of these markers were polymorphic within and among populations, amplifying 103 alleles in oil palm. Three individuals of other palm species (Cocos nucifera and two Phoenix spp.) were included as outliers. With these markers we have the power to distinguish individual palms, hence we conclude that they will facilitate association of markers with important phenotypic traits to streamline future breeding and selection. © 2016 Springer Science+Business Media New York


Koczberski G.,Curtin University Australia | Curry G.N.,Curtin University Australia | Anjen J.,PNG Oil Palm Research Association
Australian Geographer | Year: 2012

This paper reports on the authors' ongoing research with agricultural extension services, customary landowners and migrant farmers to develop a template for a Land Usage Agreement (LUA) that seeks to reconcile customary landowners' and migrants' differing interpretations of the moral basis of land rights. The LUA shows a way forward for land reform that builds on customary tenure while strengthening the temporary use rights of migrants to enable them to generate viable and relatively secure livelihoods. The paper concludes that land tenure reform should draw on what is already happening on the ground, rather than impose external models that do not accord with local cultural mores about the inalienability of customary land and its enduring social and cultural significance for customary landowning groups. © 2012 Copyright Geographical Society of New South Wales Inc.

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