aham Center For Agricultural Innovation

Orange, Australia

aham Center For Agricultural Innovation

Orange, Australia

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Sharma A.,Charles Sturt University | Khan A.N.,Charles Sturt University | Subrahmanyam S.,Charles Sturt University | Raman A.,Charles Sturt University | And 3 more authors.
Bulletin of Entomological Research | Year: 2014

Many hemipteroids are major pests and vectors of microbial pathogens, infecting crops. Saliva of the hemipteroids is critical in enabling them to be voracious feeders on plants, including the economically important ones. A plethora of hemipteroid salivary enzymes is known to inflict stress in plants, either by degrading the plant tissue or by affecting their normal metabolism. Hemipteroids utilize one of the following three strategies of feeding behaviour: salivary sheath feeding, osmotic-pump feeding and cell-rupture feeding. The last strategy also includes several different tactics such as lacerate-and-flush, lacerate-and-sip and macerate-and-flush. Understanding hemipteroid feeding mechanisms is critical, since feeding behaviour directs salivary composition. Saliva of the Heteroptera that are specialized as fruit and seed feeders, includes cell-degrading enzymes, auchenorrhynchan salivary composition also predominantly consists of cell-degrading enzymes such as amylase and protease, whereas that of the Sternorhyncha includes a variety of allelochemical-detoxifying enzymes. Little is known about the salivary composition of the Thysanoptera. Cell-degrading proteins such as amylase, pectinase, cellulase and pectinesterase enable stylet entry into the plant tissue. In contrast, enzymes such as glutathione peroxidase, laccase and trehalase detoxify plant chemicals, enabling the circumvention of plant-defence mechanisms. Salivary enzymes such as M1-zinc metalloprotease and CLIP-domain serine protease as in Acyrthosiphon pisum (Aphididae), and non-enzymatic proteins such as apolipophorin, ficolin-3-like protein and 'lava-lamp' protein as in Diuraphis noxia (Aphididae) have the capacity to alter host-plant-defence mechanisms. A majority of the hemipteroids feed on phloem, hence Ca++-binding proteins such as C002 protein, calreticulin-like isoform 1 and calmodulin (critical for preventing sieve-plate occlusion) are increasingly being recognized in hemipteroid-plant interactions. Determination of a staggering variety of proteins shows the complexity of hemipteroid saliva: effector proteins localized in hemipteran saliva suggest a similarity to the physiology of pathogen-plant interactions. © 2014 Cambridge University Press .


Norton M.R.,CSIRO | Norton M.R.,University of Queensland | Norton M.R.,aham Center For Agricultural Innovation | Lelievre F.,CNRS Center of Evolutionary and Functional Ecology | Volaire F.,CNRS Center of Evolutionary and Functional Ecology
Journal of Agronomy and Crop Science | Year: 2012

A series of trials to increase understanding of the summer dormancy trait in Phalaris aquatica was conducted. Autumn-sown and younger, spring-sown plants of two cultivars (cvv), known to contrast in expression of summer dormancy, were established and then tested over the following summer under three moisture regimes: long drought; drought+mid-summer storm; or full irrigation. The autumn-sown plants of cv. Atlas PG expressed substantial but incomplete summer dormancy under all moisture regimes and exhibited the characteristic responses including significant growth reduction and herbage senescence. The summer-dormant cv. Atlas PG used 31mm less soil water over the summer and also began to rehydrate its leaf bases from conserved soil water before the drought broke. The non-dormant cv. Australian grew whenever moisture was applied and also responded to the mid-summer storm with a decline in dehydrin expression in leaf bases, whereas no decline occurred in Atlas PG, presumably because it remained dormant. The irrigated, younger, spring-sown swards of cv. Atlas PG had restrained growth and produced only about 37% of the herbage of cv. Australian. Drought reduced activity and growth of young plants of both cultivars but while Australian regrew in response to the storm, cv. Atlas PG, grew much less (59% of Australian) indicating that dormancy, although only partially expressed after spring sowing, was reinforced by summer drought. Australian used more soil water over summer than Atlas PG, and it is suggested that this is why cv Australian is limited to the higher rainfall zones of south-eastern Australia, particularly where soil water holding capacity is limited. © 2011 Blackwell Verlag GmbH.


Volaire F.,French National Institute for Agricultural Research | Barkaoui K.,Montpellier SupAgro | Norton M.,aham Center For Agricultural Innovation
European Journal of Agronomy | Year: 2014

In many regions of the world, such as Southern Europe and most Mediterranean areas, the frequency and magnitude of droughts and heat waves are expected to increase under global warming and will challenge the sustainability of both native and sown grasslands. To analyze the adaptive strategies of species, genotypes and cultivars, we aim both (i) to understand the composition and functioning of natural grasslands and (ii) to propose ideotypes of cultivars and optimal composition for mixtures of species/genotypes under water deficit and high temperatures. This review presents a conceptual framework to analyze adaptive responses of perennial herbaceous species, starting from resistance to moderate drought with growth maintenance (dehydration avoidance and tolerance of lamina) to growth cessation and survival of plants under severe stress (dehydration avoidance and tolerance of meristems). The most discriminating functional traits vary according to these contrasting strategies because of a trade-off between resistance to moderate moisture deficit and survival of intense drought. Consequently it is crucial to measure the traits of interest in the right organs and as a function of soil water use, in order to avoid misleading interpretations of plant responses. Furthermore, collaboration between ecologists, eco-physiologists, and agronomists is required to study the combination of plant strategies in natural grasslands as only this will provide the necessary rules for species and cultivars or ecotypes assemblage. This 'agro-ecological' approach aims to identify and enhance functional complementarity and limit competition within the multi-specific or multi-genotypic material associated in mixtures since using plant biodiversity should contribute to improving grassland resistance and resilience. © 2013 Elsevier B.V.


Adams A.,Charles Sturt University | Adams A.,aham Center For Agricultural Innovation | Raman A.,Charles Sturt University | Raman A.,aham Center For Agricultural Innovation | Hodgkins D.,Charles Sturt University
Water and Environment Journal | Year: 2013

This review draws on knowledge for the treatment of heavy-metal leachate in contaminated mine sites. Mine waste rock dumps and tailings generate a continuous stream of metalliferous and saline leachate over the long term. The mining industry has many legacy sites, which have compromised aquatic ecosystems and groundwater because of heavy-metal contamination. Chemical and engineering methods are available and have been extensively utilised. However, these methods require intensive energy and often produce substantial volumes of secondary waste. We therefore argue in favour of phytoremediation as a sustainable remediation strategy leading towards efficient and sustainable metal removal and immobilisation through constructed wetlands. © 2012 CIWEM.


Perovic D.J.,Cotton Catchment Communities CRC | Perovic D.J.,Charles Sturt University | Gurr G.M.,aham Center For Agricultural Innovation | Simmons A.T.,aham Center For Agricultural Innovation | Raman A.,aham Center For Agricultural Innovation
Biocontrol Science and Technology | Year: 2011

We employed rubidium labelling to track the movement of arthropod natural enemies from a shelterbelt into an adjacent cotton field. Findings demonstrate that Dicranolaius bellulus (Coleoptera: Melyridae) and Oxyopes spp. (Araneae: Oxyopidae) move from the shelterbelt into the crop interior. Capture of rubidium-marked arthropod-predators within the cotton field provides the first hard evidence that semi-natural perennial habitats such as shelterbelts on cotton farms in Australia act as a resource for arthropod predators in adjacent crops. © 2011 Taylor & Francis.


Qawasmeh A.,Charles Sturt University | Bourke C.,Australian Department of Primary Industries and Fisheries | Lee S.,University of Western Sydney | Gray M.,University of Western Sydney | And 4 more authors.
Acta Chromatographica | Year: 2011

Profiles of volatile secondary metabolites (VSM) in Mediterranean and Continental Festuca arundinacea, either endophyte free or infected with the fungal endophyte Neotyphodium coenophialum strain AR542, were determined using gas chromatography-mass spectrometry (GC-MS). The profile of VSM in the endophyte-free Mediterranean F. arundinacea germplasm was similar to that of endophyte-free Continental F. arundinacea germplasm. However, the VSM profile in AR542-infected Mediterranean F. arundinacea was different to that in AR542-infected Continental F. arundinacea. Compound 1, identified as N-acetylnorloline, was detected in AR542-infected Mediterranean F. arundinacea as being sevenfold greater compared with its level in AR542-infected Continental F. arundinacea. Levels of compounds 2, 4, and 5 detected in AR542-infected Mediterranean F. arundinacea were significantly lower when compared with their levels in the AR542-infected Continental F. arundinacea. Levels of compound 3 were similar in both germplasms infected with endophyte strain AR542. The levels of compounds 2, 4, and 5 but not compound 3 were different between AR542 infected and endophyte free depending on germplasm. On the basis of the mass spectra obtained, compounds 2, 3, 4, and 5 were identified as tridecanoic acid methyl ester, n-capric acid, 11, 14, 17-eicosatrienoic acid, and linoleic acid ethyl ester, respectively. Our results highlight key differences between the Mediterranean and Continental germplasms. Comparison of the VSM of AR542-infected Mediterranean F. arundinacea with AR542-infected Continental F. arundinacea showed that there are quantitative differences between the two germplasms. These differences, which may impact on grazing systems involving horses, most probably arose as a result of intrinsic genetic differences between the two germplasms and are yet to be indentified.


Ni Y.,Southwest University | Guo Y.-J.,Southwest University | Wang J.,Southwest University | Xia R.-E.,Southwest University | And 3 more authors.
Plant Pathology | Year: 2014

Two Brassica napus genotypes with different resistances to Sclerotinia sclerotiorum were used to clarify whether or not the epicuticular wax is involved in the defence mechanism of B. napus to S. sclerotiorum. The total wax and wax constituents were significantly higher in the susceptible cultivar than in the resistant cultivar, except for esters. Infection by S. sclerotiorum increased the content of aldehydes in both cultivars, while increasing the content of alkanes and unknowns in the resistant cultivar. More crystalloid rods were observed on adaxial surfaces of leaves of the susceptible cultivar than on those of the resistant cultivar. The resistance to S. sclerotiorum was correlated to the responses of wax content but not the amount of total wax. The up-regulation of transcription of a wax-related gene and a pathogenesis-related gene (PR1) in the pathogen-challenged resistant cultivar also supported this observation. After inoculation, the increase in phenylalanine ammonia lyase (PAL) activity in the resistant cultivar and the decrease in the susceptible cultivar were correlated with their resistance to disease. The content of alkanes, alcohols, ketones and total wax were negatively correlated with the activities of PAL and polyphenoloxidase. After wax removal, the resistant cultivar developed more necrotic spots compared to seedlings with intact wax, whilst no significant change was observed for susceptible seedlings. These results show that epicuticular wax contributed more to the defence of resistant cultivars than susceptible cultivars. The leaf epicuticular wax, defence enzymes and salicylic acid-dependent signalling pathway all contribute to defence against S. sclerotiorum in B. napus. © 2013 British Society for Plant Pathology.


Kirkegaard J.A.,CSIRO | Conyers M.K.,aham Center for Agricultural Innovation | Hunt J.R.,CSIRO | Kirkby C.A.,CSIRO | And 2 more authors.
Agriculture, Ecosystems and Environment | Year: 2014

Adoption of conservation agriculture (CA) principles in Australia increased rapidly during the 1990s and it now boasts the highest adoption rates worldwide. These principles of (1) diverse rotations (2) reduced (or no-) till systems and (3) the maintenance of surface cover make good sense in extensive, mechanised, rain-fed cropping systems on erosion-prone, structurally-unstable soils. Indeed reduced fuel and labour costs, soil conservation and moisture retention are the most commonly stated reasons for adoption of CA principles by farmers in Australia. Yet even in Australia, while broadly applicable, the adaptation and application of CA principles within specific farming systems remains pragmatic due to the diverse biophysical and socio-economic factors encountered. Most "no-till" adopters continue some strategic tillage (~30% cropped area) for a range of sound agronomic reasons, intensive cereal systems dominate, and partial removal of crop residues as hay or by grazing livestock is commonplace within the largely mixed-farming systems. Although this challenges the notion of "ideal" CA principles (zero-till with no soil disturbance, full stubble retention and >3 species in rotations) this high degree of flexibility in CA principles as practiced in southern Australian mixed farming systems makes sense to optimize both economic and environmental outcomes. In addition, some proposed ecosystem service benefits of CA such as soil carbon sequestration and energy efficiency have been recently questioned. Though the socio-economic factors of small-holder farming systems in Africa and south Asia are more diverse and clearly different to Australian farms, some of the biophysical challenges and economic realities are shared (infertile soils, variable and extreme climates, relatively low input levels, integrated crop-livestock systems, small profit margins, highly variable income). It is therefore useful to consider from a biophysical standpoint why a pragmatic approach to CA principles has been necessary, even in a relatively high-adopting country like Australia, and why we should expect similarly 'imperfect' adoption of CA (if at all) in the diverse smallholder systems of Sub-Saharan Africa and South Asia. We review aspects of CA adoption in Australia in an effort to draw out important lessons as CA principles are adapted elsewhere, including the smallholder farming systems of Sub-Saharan Africa and South Asia. © 2013 Elsevier B.V.


Hayesa R.C.,aham Center For Agricultural Innovation | Lia G.D.,aham Center For Agricultural Innovation | Deara B.S.,aham Center For Agricultural Innovation | Conyersa M.K.,aham Center For Agricultural Innovation | And 2 more authors.
New Zealand Journal of Agricultural Research | Year: 2010

Perennial-based pasture swards potentially offer land managers the capacity for recharge control in temperate cropping zone environments to satisfy the dual role of fostering increased agricultural productivity and reduced deep drainage. This study used a neutron moisture meter to monitor levels of stored soil water to 1.70m under pastures sown to lucerne (Medicago sativa L.), phalaris (Phalaris aquatica L.), chicory (Cichorium intybus L.), perennial veldt grass (Ehrhata calcycina Sm.), grazing brome (Bromus stamineus E. Desv.), plantain (Plantago lanceolata L.), Rhodes grass (Chloris gayana Kunth), tall fescue (Festuca arundinacea syn. Lolium arundinaceum Schreb. syn. Schedonorus phoenix (Scop.) Holub.) and cocksfoot (Dactylis glomerata L.) in two contrasting environments in the cropping zone of southern New South Wales (NSW), Australia. Performance of two cultivars with contrasting levels of summer activity of each of the latter two species was also assessed. Differences in soil water between the various treatments were small but significant throughout the 5-year study due to successive below average rainfall years. However, the study demonstrated that lucerne remains the perennial pasture species with the greatest capacity to dry the soil profile for recharge control. Lucerne was the most persistent species under drought of all species evaluated, creating the largest total dry soil deficit at both sites (214 and 138mm at Cootamundra and Wagga Wagga, respectively). There was a significant positive correlation (P<.05) between persistence (measured as basal frequency from year 3 onwards) and percentage decrease in soil water content at both sites (R2-0.63 and 0.68, respectively). Kasbah cocksfoot, Fraydo tall fescue, phalaris, chicory and perennial veldt grass all persisted moderately well and created dry soil buffers that were not significantly lower than lucerne at both sites (mean 200 and 133 mm, respectively). In contrast to previous findings, summer-active cultivars of cocksfoot and tall fescue did not show any advantage in drying soils in low-rainfall environments compared with more summer-dormant cultivars. The summer-dormant cultivars of each species were shown to be more persistent, enabling them to dry the soil profile incrementally over a longer period of time. This study has demonstrated the importance of increased plant persistence on reducing the water content of the soil profile in drought-prone environments. © 2010 The Royal Society of New Zealand.


Hayesa R.C.,aham Center For Agricultural Innovation | Deara B.S.,aham Center For Agricultural Innovation | Lia G.D.,aham Center For Agricultural Innovation | Virgonaa J.M.,aham Center For Agricultural Innovation | And 3 more authors.
New Zealand Journal of Agricultural Research | Year: 2010

Perennial-based pasture swards potentially offer land managers the capacity for recharge control in temperate cropping zone environments to satisfy the dual role of fostering increased agricultural productivity and reduced deep drainage. This study evaluated the productivity, persistence and herbage quality of lucerne (Medicago sativa L.), phalaris (Phalaris aquatica L.), chicory (Cichorium intybus L.), perennial veldt grass (Ehrhata calcycina Sm.), grazing brome (Bromus stamineus E. Desv.), plantain (Plantago lanceolata L.), Rhodes grass (Chloris gayana Kunth), tall fescue (Festuca arundinacea syn. Lolium arundinaceum Schreb. syn. Schedonorus phoenix (Scop.) Holub.) and cocksfoot (Dactylis glomerata L.) in two contrasting environments in the cropping zone of southern New South Wales (NSW), Australia. The performance of two cultivars with contrasting levels of summer activity of each of the latter two species was also assessed. Lucerne was the most productive species evaluated, producing 54-85% more herbage than phalaris, the next most productive species. Lucerne was also the most persistent species with a higher basal frequency than all other species during the experimental period and, averaged across samplings, had the highest crude protein (22.3%) in the leaf and stem of any species. Chicory herbage had the highest dry matter digestibility (76.7%) and ash content (15.1%) and lowest neutral (35.4%) and acid detergent fibre contents (21.8%) compared with the other species. The more summer-dormant cultivars of cocksfoot (cv. Kasbah) and tall fescue (cv. Fraydo) were both found to be more persistent than their semi-summer-active counterparts (cvv. Currie and Demeter, respectively), demonstrating the importance of summer dormancy for the persistence of both species in these environments. Tall fescue cv. Fraydo was equally persistent yet produced only 42-51% of the cumulative biomass of phalaris over 5 years, indicating that tall fescue is not a viable species in these drought-prone environments, nor were plantain and grazing brome due to their inferior productivity and persistence. The study highlighted the lack of viable perennial pasture options currently available in cropping zone environments of southern NSW other than lucerne, phalaris and the summer-dormant cultivar of cocksfoot, Kasbah. Chicory and perennial veldt grass, with further breeding and selection under Australian environmental conditions, could have the potential to be viable perennial pasture options for the cropping zone of southern NSW. © 2010 The Royal Society of New Zealand.

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