A non-papillate, heterothallic Phytophthora species first isolated in 2001 and subsequently from symptomatic roots, crowns and stems of 33 plant species in 25 unrelated botanical families from 13 countries is formally described here as a new species. Symptoms on various hosts included crown and stem rot, chlorosis, wilting, leaf blight, cankers and gumming. This species was isolated from Australia, Hungary, Israel, Italy, Japan, the Netherlands, Norway, South Africa, Spain, Taiwan, Turkey, the United Kingdom and United States in association with shrubs and herbaceous ornamentals grown mainly in greenhouses. The most prevalent hosts are English ivy (Hedera helix) and Cistus (Cistus salvifolius). The association of the species with acorn banksia (Banksia prionotes) plants in natural ecosystems in Australia, in affected vineyards (Vitis vinifera) in South Africa and almond (Prunus dulcis) trees in Spain and Turkey in addition to infection of shrubs and herbaceous ornamentals in a broad range of unrelated families are a sign of a wide ecological adaptation of the species and its potential threat to agricultural and natural ecosystems. The morphology of the persistent non-papillate ellipsoid sporangia, unique toruloid lobate hyphal swellings and amphigynous antheridia does not match any of the described species. Phylogenetic analysis based on sequences of the ITS rDNA, EF-1α, and β-tub supported that this organism is a hitherto unknown species. It is closely related to species in ITS clade 7b with the most closely related species being P. sojae. The name Phytophthora niederhauserii has been used in previous studies without the formal description of the holotype. This name is validated in this manuscript with the formal description of Phytophthora niederhauserii Z.G. Abad et J.A. Abad, sp. nov. The name is coined to honor Dr John S. Niederhauser, a notable plant pathologist and the 1990 World Food Prize laureate.

Since the 2007 meeting a number of new Phytophthora species have been described. A number of these appear to be associated with woodland and forest tree declines, but may have been misidentified in earlier work. These will be reviewed and updates provided. At least two ‘Fishing for Phytophthora’ activities have been undertaken and new Phytophthora species together with hybrid species are evident. Significant community driven projects are being undertaken in Western Australia and elsewhere relating to mapping, prioritisation of areas for hygiene and phosphite activities, effective communication to the wider public and initiatives to obtain on-going funding to Phytophthora management. Eradication and containment activities are now being put into practice in wild land communities in Western Australia. At the research level there are a number of applied and basic research studies on understanding, Phytophthora in nurseries and urban parklands and reserves, Phytophthora and fire, host resistance, the action of phosphite at a molecular and biochemical level, and how phosphite induces a phosphate starvation response in plants and possible implications. These research activities and more will be reviewed.

The eucalypt pathogen, Phytophthora fallax , is reported for the first time in Australia. In June 2006 P. fallax was isolated from soil in Kinglake State Park, Victoria. Attempts to reisolate the pathogen from soil and eucalypts in the area were unsuccessful. The pathogen was isolated again in May 2007 from soil collected in the Mornington Shire, Victoria. In October 2007 P. fallax was baited from a rainwater gauge in Powelltown, Victoria. None of the findings were associated with eucalypt disease.

Phytophthora ramorum is an invasive plant pathogen causing considerable and widespread damage in nurseries, gardens and natural woodland ecosystems of the USA and Europe and is classified as a Category 1 pest in Australia. It is of particular interest to Australian plant biosecurity as, like Phytophthora cinnamomi, it has the potential to become a major economic and ecological threat in areas with susceptible hosts and conducive climate. At least three Australian host species have been discovered so far, Eucalyptus haemastoma, Eucalyptus gunnii and Pittosporum undulatum. Asymptomatic sporulation has been confirmed recently for a number of New Zealand species, including a species of Leptospermum, a genus that is widespread throughout Australia within areas of climatic suitability for P. ramorum. Results will be presented of research undertaken in the USA to assess pathogenicity of P. ramorum on Australian native plants and to determine sporulation and survival potential on both symptomatic and asymptomatic tissues. Test species have been selected and sourced from established gardens and nurseries based upon their provenance in regard to areas of climatic suitability for P. ramorum, their relation to known hosts of P. ramorum and their ecological and economical importance to Australian plant industries. Prior screening for the presence of Phytophthora species in the soil profile, and on foliage of selected test species is being conducted. Susceptibility is to be tested using unwounded, detached plant materials, and then scaled up to natural infection studies. Presence and abundance of reproductive structures, sporangia and chlamydospores, will be assessed for all hosts.

The role of biotic agents in the dieback syndrome Mundulla Yellows (MY) was investigated by analysis of 40 Eucalyptus camaldulensis, E. leucoxylon, or E. cladocalyx trees and soil samples from South Australia and Victoria, Australia. No pathogenic fungi, bacteria, phytoplasmas, or insect pests or vectors were found to be associated with MY. However, nematode analysis identified Merlinius spp. to be associated with soil, but not roots, from symptomatic trees. Interveinal chlorosis symptoms were not transmissible by seed, mechanical inoculation, or grafting using plant material derived from symptomatic trees. Virus-like particles were detected at a single symptomatic study site using transmission electron microscopy. MY symptoms were induced in E. camaldulensis seedlings by sowing seed from asymptomatic trees into sterilized and unsterilized soil collected from underneath symptomatic trees. Significantly, sterilized soil induced more severe symptoms in seedlings than unsterilized soil. Soil collected from under asymptomatic trees did not induce MY symptoms. This preliminary investigation indicates that, with the exception of Merlinius spp., pathogenic organisms and pests were not consistently associated with MY symptoms.

This paper reports the intrinsic reactivity to oxygen (the rate of reaction per unit surface of pore area, ρi) of fine particles of three coal chars. The chars were prepared from a swelling low-volatile bituminous coal, a non-swelling low-volatile bituminous coal and a brown coal. Rate measurements were made under two conditions: in a low-temperature fixed-bed reactor where chemical processes alone controlled burning rates; and in a high-temperature entrained flow reactor, where pore diffusion had a strong effect on rates. The intrinsic reactivities at high temperature were determined using measured values of the pore diffusion coefficient (De) and other measured properties without the need to use any structural model of the chars' pore systems. The diffusion coefficients were measured using a non-isobaric chromatographic technique, the resulting coefficients being much smaller and having a higher temperature dependence than the corresponding Knudsen diffusion coefficients calculated using Wheeler's ‘average pore size’ structural model. It is concluded that these independent measurements of pore diffusivity, at moderately high temperatures give values which are more relevant to the kinetic processes involved in coal combustion than those determined using simplistic structural models. For the samples considered here, intrinsic reactivities, determined from measured diffusion coefficients and reaction rates, were in close agreement with those predicted on the basis of earlier models.

A pulse ignition technique, whereby a small mass of fine coal or char particles is fed into a drop-tube furnace, was used to evaluate the ignition characteristics of pulverized fuel particles. Combustion rates were estimated from the ignition temperatures and were compared with rates determined experimentally using a fixed-bed reactor, DTG, and an entrained-flow reactor. Three Australian coals, two chars prepared from these coals and a petroleum coke were used. Coal rank and particle size were found to influence the ignition temperatures of the coal and char particles. However, these effects were reduced at high oxygen concentrations. In pure oxygen, the ignition temperatures of the chars and their parent coals were similar. Heterogeneous and homogeneous ignition theories indicated that at low O2 concentrations ignition was controlled by a homogeneous mechanism, whereas at high O2 concentrations heterogeneous ignition became dominant. The combustion rates of the chars determined by the four techniques were compared at an oxygen partial pressure of 10.1 kPa. The results of the fixed-bed, DTG and entrained flow experiments were consistent with each other and spanned the range of kinetic control from regime I at low temperature (fixed bed) to regime II at high temperature (entrained flow). The drop-tube experiments indicated consistently higher combustion rates than did the other techniques. The pulse ignition measurements therefore, while providing a valid means of characterizing coal and char ignition behaviour, result in overestimation of the char combustion rate.

The intrinsic reactivity of a petroleum coke and an Australian brown coal char to carbon dioxide, steam and oxygen have been measured in a fixed bed reactor using techniques which allow the reaction rate, activation energy and the order of reaction with respect to reactant concentration to be determined under conditions where chemical processes alone control the rate of reaction. Samples were recovered at various extents of reaction up to approximately 40% weight loss and changes in particle density and surface area determined. Reaction rates varied significantly as the reactions proceeded and these variations could be largely, but not completely, attributed to changes in surface area. The order of reaction was similar for the reactions of both carbons with all three reactant gases and remained essentially constant, at a value of approximately 0.6, during oxidation of up to 40% of the sample mass. The activation energy for reaction of both materials also remained unchanged during reaction and was similar for reaction of both carbons with CO 2 and H 2 O, where values in the range 214–242 kJ/mol were determined. Activation energies of 155 and 127 kJ/mol were measured for reaction with oxygen of petroleum coke and brown coal char respectively. The relative intrinsic reaction rates of petroleum coke at 1073 K and CO 2 , H 2 O and O 2 partial pressures of 0.2 atm were found to be 1, 0.2 and 0.9×10 5 respectively. The corresponding relativities for brown coal char were 1, 2, and 0.1×10 5 .

This paper reports the use of the two-phase bubbling fluidized-bed model for calculations of the conditions in fluidized-bed combustors. The model takes account of the sequential steps of oxygen transport from bubble to dense phases, transport through the dense phase, and finally reaction with the fuel particle. At 1200 K, for practical conditions of pressure, fluidizing velocity, particle size, bed voidage and bubble size, fuel reactivity was sufficiently high, and bubble-to-dense phase transport sufficiently rapid, to ensure that neither of these steps had a notable rate-controlling effect. Transport through the dense phase was of most influence. However, some effect of reactivity was shown at 1000 K, and a strong effect occurred at 800 K. The model proved to be markedly sensitive to the carbon concentration in the bed, bubble size, and particle size.

Measurements were made of the reaction rate of three sizes (2.9, 0.9 and 0.22 mm) of petroleum-coke particles with carbon dioxide over the temperature range 1018–1178 K, and at carbon dioxide partial pressures between 26 and 118 kPa. A limited number of similar measurements were made on samples of a commercial aluminium-smelting anode, an experimental anode, and AGKSP graphite. The materials were all reacted under conditions of chemical rate control alone: there were no rate limitations due to transport processes without or within the carbon particles. The order of the rate with respect to carbon dioxide concentration was found to be close to 0.6 for the petroleum coke and anode carbons, and between 0.6 and 0.8 for the graphite. Activation energies in the range 203–237 kJ/mol were found for petroleum coke; 187–237 kJ/mol for electrode carbon; and 293 kJ/mol for the graphite. For the petroleum coke, the order was found to be constant up to 45% burn-off and the activation energy essentially constant between 21 and 45% burn-off. The reactivity ϱs, based on unit pore surface area of the petroleum coke at a carbon dioxide pressure of 101 kPa, can be represented by: ϱs = α exp [−E(RT)]. For the 2.9 and 0.9 mm particles, α = 6.1 /sx 106 g/m2 min and E = 215 kJ/mol; for the 0.22 mm particles the respective values are 1.8 /sx 107 and 222. The reactivity ϱ of the commercial electrode on a weight basis was within the range of those of the coke and experimental electrode. For AGKSP graphite, values of ϱs were close to those found by Walker and Raats14.