Developments in phosphine resistance in China and possible implications for Australia

Resistance to phosphine was characterised in strains of rice weevil, Sirophilus oryzae, and the psocids Liposcelis entomophila and L. decolor from China and Australia. Mixed-age cultures (containing all life stages) of insects were tested using a flow-through apparatus. The criterion of response was 'time to population extinction' defined as the exposure period, in days, at which 100% mortality of adults and no live progeny were achieved. Chinese S. oryzae took 11 and 7 days for population extinction at 200 and 700 ppm phosphine, respectively, compared with the Australian strain, which was controlled in 7 and 5 days, respectively. Similarly, the Chinese strains L. Enfornophila and L. decolor were generally more difficult to control than the corresponding Australian strains. The Chinese strains of L. decolor showed resistance levels stronger than any grain storage insect pest species so far detected in Australia. This research allows us to evaluate the likely significance of potential new resistance to the Australian grain industry and to prepare effective fumigation dosages and resistance management strategies to combat new strong resistances before they emerge here.

Sown pasture grasses and legumes for marginal cropping lands in southern inland Queensland

A rich suite of pasture legumes and grasses have been released for the Queensland grain belt, particularly from forage evaluation programs carried out during the past 50 years (Gramshaw and Walker 1988; http://www.pi.csiro.au/ahpc/). Thus, there is an extensive and comprehensive knowledge of the adaptation of those species and adaptation is being extended widely - for example, to farmer groups in 'LeyGrain' workshops developed and delivered by the authors, and as written information (e.g. Lloyd et al. 2006; 2007a; 2007b) and on the website www.dpi.qld.gov.au. However, our knowledge is broad and, as we come to understand natural systems, their limitations and the extent of variation within those systems, it is equally clear that our knowledge of pasture plant adaptation is not as well defined as it needs to be. It is an interesting conflict - the more we understand, the more we begin to realise our lack of understanding. The appropriate species for sowing in different situations are discussed.

Action learning in partnership with Landcare and catchment management groups to support increased pasture sowings in southern inland Queensland

The incorporation of sown pastures as short-term rotations into the cropping systems of northern Australia has been slow. The inherent chemical fertility and physical stability of the predominant vertisol soils across the region enabled farmers to grow crops for decades without nitrogen fertiliser, and precluded the evolution of a crop–pasture rotation culture. However, as less fertile and less physically stable soils were cropped for extended periods, farmers began to use contemporary farming and sown pasture technologies to rebuild and maintain their soils. This has typically involved sowing long-term grass and grass–legume pastures on the more marginal cropping soils of the region. In partnership with the catchment management authority, the Queensland Murray–Darling Committee (QMDC) and Landcare, a pasture extension process using the LeyGrain™ package was implemented in 2006 within two Grain & Graze projects in the Maranoa-Balonne and Border Rivers catchments in southern inland Queensland. The specific objectives were to increase the area sown to high quality pasture and to gain production and environmental benefits (particularly groundcover) through improving the skills of producers in pasture species selection, their understanding and management of risk during pasture establishment, and in managing pastures and the feed base better. The catalyst for increasing pasture sowings was a QMDC subsidy scheme for increasing groundcover on old cropping land. In recognising a need to enhance pasture knowledge and skills to implement this scheme, the QMDC and Landcare producer groups sought the involvement of, and set specific targets for, the LeyGrain workshop process. This is a highly interactive action learning process that built on the existing knowledge and skills of the producers. Thirty-four workshops were held with more than 200 producers in 26 existing groups and with private agronomists. An evaluation process assessed the impact of the workshops on the learning and skill development by participants, their commitment to practice change, and their future intent to sow pastures. The results across both project catchments were highly correlated. There was strong agreement by producers (>90%) that the workshops had improved knowledge and skills regarding the adaptation of pasture species to soils and climates, enabling a better selection at the paddock level. Additional strong impacts were in changing the attitudes of producers to all aspects of pasture establishment, and the relative species composition of mixtures. Producers made a strong commitment to practice change, particularly in managing pasture as a specialist crop at establishment to minimise risk, and in the better selection and management of improved pasture species (particularly legumes and the use of fertiliser). Producers have made a commitment to increase pasture sowings by 80% in the next 5 years, with fourteen producers in one group alone having committed to sow an additional 4893 ha of pasture in 2007–08 under the QMDC subsidy scheme. The success of the project was attributed to the partnership between QMDC and Landcare groups who set individual workshop targets with LeyGrain presenters, the interactive engagement processes within the workshops themselves, and the follow-up provided by the LeyGrain team for on-farm activities.

DNA-based identification of Quambalaria pitereka causing severe leaf blight of Corymbia citriodora in China

Quambalaria spp. include serious plant pathogens, causing leaf and shoot blight of Corymbia and Eucalyptus spp. In this study, a disease resembling Quambalaria leaf blight was observed on young Corymbia citriodora trees in a plantation in the Guangdong Province of China. Comparisons of rDNA sequence data showed that the causal agent of the disease is Q. pitereka. This study provides the first report of Quambalaria leaf blight from China, and it is also the first time that this pathogen has been found on trees outside the native range of Eucalypts.

Increasing production from inland aquaculture in Papua New Guinea

There are more than 10,000 small-scale fish farms in PNG producing tilapia, carp or trout for home consumption and sale. Interest in aquaculture is growing rapidly, and the government has given high priority to aquaculture development, in recognition of its potential contribution to achieving food security particularly in the inland areas. Significant constraints include lack of capability within management agencies to identify appropriate sites for pond development, inadequate supply and poor quality of fingerlings, limited availability and high cost of pond fertilisers and suitable feeds, and a general lack of knowledge and training on aquaculture husbandry skills.

Risk-based surveillance for avian influenza control along poultry market chains in South China: The value of social network analysis.

Over the past two decades, the poultry sector in China went through a phase of tremendous growth as well as rapid intensification and concentration. Highly pathogenic avian influenza virus (HPAIV) subtype H5N1 was first detected in 1996 in Guangdong province, South China and started spreading throughout Asia in early 2004. Since then, control of the disease in China has relied heavily on wide-scale preventive vaccination combined with movement control, quarantine and stamping out. This strategy has been successful in drastically reducing the number of outbreaks during the past 5 years. However, HPAIV H5N1 is still circulating and is regularly isolated in traditional live bird markets (LBMs) where viral infection can persist, which represent a public health hazard for people visiting them. The use of social network analysis in combination with epidemiological surveillance in South China has identified areas where the success of current strategies for HPAI control in the poultry production sector may benefit from better knowledge of poultry trading patterns and the LBM network configuration as well as their capacity for maintaining HPAIV H5N1 infection. We produced a set of LBM network maps and estimated the associated risk of HPAIV H5N1 within LBMs and along poultry market chains, providing new insights into how live poultry trade and infection are intertwined. More specifically, our study provides evidence that several biosecurity factors such as daily cage cleaning, daily cage disinfection or manure processing contribute to a reduction in HPAIV H5N1 presence in LBMs. Of significant importance is that the results of our study also show the association between social network indicators and the presence of HPAIV H5N1 in specific network configurations such as the one represented by the counties of origin of the birds traded in LBMs. This new information could be used to develop more targeted and effective control interventions.

Pasture management for the inland Burnett

The beef industry is a major contributor to the wealth of the Inland Burnett region and this valuable industry relies on productive pastures. This booklet aims to help graziers better understand the development and management of the pastures suited to the region. PR09-4633.

Growing organic prawns - in inland saline waters

This report details the results of research into organic production of prawns in Australia. This has involved activities and experiments over two years at several sites and using a multidisciplinary approach. This includes farm trials at an inland demonstration prawn farm which solely utilises saline bore water, sample collection from two commercial prawn farms in coastal regions of south-eastern Queensland, replicated feed trials at one of DPI&F’s aquaculture research stations, specified feed manufacture at the laboratories of University of Queensland, and packaging and product storage trials and food analyses at two of DPI&F’s food technology laboratories. This work was designed to investigate and assist in the possible adoption of organic procedures by the Australian prawn farming industry. The import from Asia of cheaply produced prawns has forced all Australian prawn farmers to review their marketing procedures. Additionally investors are becoming increasingly concerned at the prospects for the expansion of this industry in Australia. Since the competition of seafood products in the marketplace is increasing on a global basis, alternate products are being investigated by those wishing to maintain and/or grow their market share. The premium paid for organic food products would hopefully provide an economic incentive for farmers to convert to organic production systems, with an added advantage that the standards that apply have beneficial implications also for the social and environmental practices of industry.

Optimizing Hill Seeding Density for High-Yielding Hybrid Rice in a Single Rice Cropping System in South China

Mechanical hill direct seeding of hybrid rice could be the way to solve the problems of high seeding rates and uneven plant establishment now faced in direct seeded rice; however, it is not clear what the optimum hill seeding density should be for high-yielding hybrid rice in the single-season rice production system. Experiments were conducted in 2010 and 2011 to determine the effects of hill seeding density (25 cm 615 cm, 25 cm 617 cm, 25 cm 619 cm, 25 cm 621 cm, and 25 cm 623 cm; three to five seeds per hill) on plant growth and grain yield of a hybrid variety, Nei2you6, in two fields with different fertility (soil fertility 1 and 2). In addition, in 2012 and 2013, comparisons among mechanical hill seeding, broadcasting, and transplanting were conducted with three hybrid varieties to evaluate the optimum seeding density. With increases in seeding spacing from 25 cm615 cm to 25 cm623 cm, productive tillers per hill increased by 34.2% and 50.0% in soil fertility 1 and 2. Panicles per m2 declined with increases in seeding spacing in soil fertility 1. In soil fertility 2, no difference in panicles per m2 was found at spacing ranging from 25 cm617 cm to 25 cm623 cm, while decreases in the area of the top three leaves and aboveground dry weight per shoot at flowering were observed. Grain yield was the maximum at 25 cm 617 cm spacing in both soil fertility fields. Our results suggest that a seeding density of 25 cm617 cm was suitable for high-yielding hybrid rice. These results were verified through on-farm demonstration experiments, in which mechanical hill-seeded rice at this density had equal or higher grain yield than transplanted rice

Anthelmintic resistance in ovine gastrointestinal nematodes in inland southern Queensland

Objective To establish the prevalence of anthelmintic resistance in ovine gastrointestinal nematodes in southern Queensland. Design An observational parasitological study using the faecal egg count reduction test. Methods Sheep farms (n = 20) enrolled in this study met the twin criteria of using worm testing for drench decisions and having concerns about anthelmintic efficacy. On each farm, 105 sheep were randomly allocated to one of six treatment groups or an untreated control group. Faecal samples were collected on day 0 and days 10–14 for worm egg counts and larval differentiation. Single- and multi-combination anthelmintics, persistent and non-persistent, oral liquid or capsule, pour-on and injectable formulations were tested. Monepantel was not tested. Farmers also responded to a questionnaire on drenching practices. Results Haemonchus contortus was the predominant species. Efficacy <95% was recorded on 85% of farms for one or more anthelmintics and on 10% of farms for six anthelmintics. No resistance was identified on three farms. The 4-way combination product was efficacious (n = 4 farms). Napthalophos resistance was detected on one farm only. Resistance to levamisole (42% of farms), moxidectin injection (50% of farms) and the closantel/abamectin combination (67% of farms) was identified. Moxidectin oral was efficacious against Trichostrongylus colubriformis, which was predominant on only one farm. Of the farms tested, 55% ran meat breeds, 60% dosed more than the recommended dose rate and 70% always, mostly or when possible practised a ‘drench and move’ strategy. Conclusion This level of anthelmintic resistance in southern Queensland will severely compromise worm control and force increased use of monepantel.

Status of soil nematode communities during natural regeneration of a subtropical forest in southwestern China

Forest recovery has been extensively evaluated using plant communities but fewer studies have been conducted on soil fauna. This study reports the status of soil nematode communities during natural re-establishment after deforestation in a subtropical forest in southwestern China. Soil nematode communities of two secondary succession stages, shrub-grassland and secondary forest, were compared with those of virgin forest. Shrub-grassland had higher herbivore relative abundance but lower fungivore and bacterivore relative abundance than forests. Between secondary and virgin forest, the latter had higher abundance of bacterivores. Shrub-grassland had lower nematode diversity, generic richness, maturity index and trophic diversity index than virgin forest, whereas there were no differences in these indices between secondary forest and virgin forest. The small differences in nematode community structures between secondary forest and virgin forest suggest that soil nematode communities recovered to a level close to that of the undisturbed forest after up to 50 years of natural succession.

Polyphasic characterization of four new plant pathogenic Phyllosticta species from China, Japan, and the United States

The black rot disease of Vitis species and other host genera of Vitacease is caused by Phyllosticta ampelicida and allied taxa which is considered to be a species complex. In this paper, we introduce four new species of Phyllosticta, including two from the P. ampelicida complex, based on a polyphasic characterization including disease symptoms and host association, morphology, and molecular phylogeny. The phylogenetic analysis was conducted based on the ribosomal internal transcribed spacer (ITS) region and a combined multi-locus alignment of the ITS, actin (ACT), partial translation elongation factor 1-alpha (TEF-1), and glyceraldehydes 3-phosphate dehydrogenase (GPDH) gene regions. Our study confirms the phylogenetic distinctions of the four new species, as well as their phenotypic differences with known species in the genus.