Tan Y.P.,Plant Pathology Herbarium |
Edwards J.,Australian Department of Primary Industries and Fisheries |
Grice K.R.E.,Agri Science Queensland |
Shivas R.G.,Plant Pathology Herbarium
Fungal Diversity | Year: 2013
Six new species of Diaporthe, D. beilharziae on Indigofera australis, D. fraxini-angustifoliae on Fraxinus angustifolia subsp. oxycarpa, D. litchicola on Litchi chinensis, D. nothofagi on Nothofagus cunninghamii, D. pascoei on Persea americana and D. salicicola on Salix purpurea from Australia are described and illustrated based on morphological characteristics and molecular analyses. Three of the new species no longer produced sporulating structures in culture and two of these were morphologically described from voucher specimens. Phylogenetic relationships of the new species with other Diaporthe species are revealed by DNA sequence analyses based on the internal transcribed spacer (ITS) region, and partial regions of the β-tubulin (BT) and translation elongation factor 1-alpha (TEF). © 2013 Mushroom Research Foundation.
Viscarra Rossel R.A.,CSIRO |
Adamchuk V.I.,McGill University |
Sudduth K.A.,U.S. Department of Agriculture |
McKenzie N.J.,CSIRO |
Lobsey C.,Agri Science Queensland
Advances in Agronomy | Year: 2011
This chapter reviews proximal soil sensing (PSS). Our intent is for it to be a source of up-to-date information on PSS, the technologies that are currently available and their use for measuring soil properties. We first define PSS and discuss the sampling dilemma. Using the range of frequencies in the electromagnetic spectrum as a framework, we describe technologies that can be used for PSS, including electrochemical and mechanical sensors, telemetry, geographic positioning and elevation, multisensor platforms, and core measuring and down-borehole sensors. Because soil properties can be measured with different proximal soil sensors we provide examples of the alternative techniques that are available for measuring soil properties. We also indicate the developmental stage of technologies for PSS and the current approximate cost of commercial sensors. Our discussion focuses on the development of PSS over the past 30. years and on its current state. Finally, we provide a short list of general considerations for future work and suggest that we need research and development to: (i) improve soil sampling designs for PSS, (ii) define the most suitable technique or combination of techniques for measuring key soil properties, (iii) better understand the interactions between soil and sensor signals, (iv) derive theoretical sensor calibrations, (v) understand the basis for local versus global sensor calibrations, (vi) improve signal processing, analysis and reconstruction techniques, (vii) derive and improve methods for sensor data fusion, and (viii) explore the many and varied soil, agricultural, and environmental applications where proximal soil sensors could be used. PSS provides soil scientists with an effective approach to learn more about soils. Proximal soil sensors allow rapid and inexpensive collection of precise, quantitative, fine-resolution data, which can be used to better understand soil spatial and temporal variability. We hope that this review raises awareness about PSS to further its research and development and to encourage the use of proximal soil sensors in different applications. PSS can help provide sustainable solutions to the global issues that we face: food, water, and energy security and climate change. © 2011 Elsevier Inc.
Chenu K.,University of Queensland |
Deihimfard R.,Agri Science Queensland |
Deihimfard R.,Shahid Beheshti University |
New Phytologist | Year: 2013
Plant response to drought is complex, so that traits adapted to a specific drought type can confer disadvantage in another drought type. Understanding which type(s) of drought to target is of prime importance for crop improvement. Modelling was used to quantify seasonal drought patterns for a check variety across the Australian wheatbelt, using 123 yr of weather data for representative locations and managements. Two other genotypes were used to simulate the impact of maturity on drought pattern. Four major environment types summarized the variability in drought pattern over time and space. Severe stress beginning before flowering was common (44% of occurrences), with (24%) or without (20%) relief during grain filling. High variability occurred from year to year, differing with geographical region. With few exceptions, all four environment types occurred in most seasons, for each location, management system and genotype. Applications of such environment characterization are proposed to assist breeding and research to focus on germplasm, traits and genes of interest for target environments. The method was applied at a continental scale to highly variable environments and could be extended to other crops, to other drought-prone regions around the world, and to quantify potential changes in drought patterns under future climates. © 2013 New Phytologist Trust.
Moore A.D.,CSIRO |
Robertson M.J.,CSIRO |
Routley R.,Agri Science Queensland
Agricultural Systems | Year: 2011
Water is the principal limiting resource in Australian broadacre farming, and the efficiency with which farmers use water to produce various products is a major determinant both of farm profit and of a range of natural resource management (NRM) outcomes. We propose a conceptual framework based on multiple water use efficiencies (WUEs) that can be used to gain insight into high-level comparisons of the productivity and sustainability of alternative farming practices across temporal and spatial scales. The framework is intended as a data aggregation and presentation device. It treats flows of water, biomass and money in a mixed farming system; economic inefficiencies in these flows are tracked as they are associated with a range of NRM indicators. We illustrate the use of the framework, and its place in a larger research programme, by employing it to synthesise the results from a set of modelling analyses of the effect of land use choices on long-term productivity and a range of NRM indicators (frequency of low ground cover, deep drainage, N leaching rates and rate of change in surface soil organic carbon). The analyses span scales from single paddocks and years to whole farms and have been carried out with the APSIM and GRAZPLAN biophysical simulation models and the MIDAS whole-farm economic model. In single wheat crops in one study, different land uses in preceding years affect grain yield primarily by affecting the harvest index. When the scale changes to cropping rotations, the critical factor affecting overall water use efficiency is found to be the proportion of stored soil water that is transpired by crops. When ordinated in terms of their water use efficiencies, a set of 45 modelled rotation sequences at another location are differentiated mainly by the proportion of pasture in the rotation; when rotations are ordinated using key NRM indicators, the proportion of lucerne pasture is the main distinguishing factor. Finally, we show that for whole crop-livestock farms at three different locations across southern Australia, the pattern of water use efficiencies in the most profitable farming systems changes in similar ways as cropping proportion is altered. At this scale, land use choices affect multiple water use efficiency indices simultaneously and commodity prices determine the balance of the resulting economic tradeoffs. Limitations to the use of the WUE framework arising from its relative simplicity are discussed, as are other areas of farming systems research and development to which it can be applied. © 2010 Elsevier Ltd.
Misra R.K.,University of Southern Queensland |
Padhi J.,University of Southern Queensland |
Payero J.O.,Agri Science Queensland
Journal of Hydrology | Year: 2011
We used twelve load cells (20. kg capacity) in a mini-lysimeter system to measure evapotranspiration simultaneously from twelve plants growing in separate pots in a glasshouse. A data logger combined with a multiplexer was used to connect all load cells with the full-bridge excitation mode to acquire load-cell signal. Each load cell was calibrated using fixed load within the range of 0-0.8 times the full load capacity of load cells. Performance of all load cells was assessed on the basis of signal settling time, excitation compensation, hysteresis and temperature. Final calibration of load cells included statistical consideration of these effects to allow prediction of lysimeter weights and evapotranspiration over short-time intervals for improved accuracy and sustained performance. Analysis of the costs for the mini-lysimeter system indicates that evapotranspiration can be measured economically at a reasonable accuracy and sufficient resolution with robust method of load-cell calibration. © 2011 Elsevier B.V.
Dixon R.M.,Agri Science Queensland |
Animal Feed Science and Technology | Year: 2010
In the seasonally dry tropics the productivity of grazing cattle is often constrained by nutrition, particularly during the dry season. An experiment during 2 annual cycles estimated the diet selected by grazing Bos indicus heifers, and their growth and growth responses to a non-protein N supplement. Two drafts (groups) of 2 herds (10 heifers per herd) grazed a pasture consisting of buffel grass (Cenchrus ciliaris) with some legume and edible browse, and herds were offered loose mineral mix (LMM) supplements either without (control) or with urea. Near infrared reflectance spectroscopy measurement of faeces (F.NIRS) was used to estimate each 2 weeks the non-grass and crude protein (CP) concentrations, and DM digestibility (DMD) of the diet selected. Rainfall and diet quality generally followed the seasonal pattern expected for the region and for the seasonally dry tropics. Non-grass (i.e. dicotyledonous species) content averaged 0.13 (S.D. 0.053) of the diet and did not appear to be related to season, but during the first dry season and wet season the urea supplemented heifers selected diets lower (P<0.01 and P<0.05, respectively) in non-grass than the control heifers. Diet quality was generally low during the dry seasons, increased sharply after the seasonal break, and later declined gradually through the wet seasons and wet-dry transition seasons. During the dry seasons average diet CP ranged from 33 to 49 g/kg and diet DMD from 0.480 to 0.507. During the 2 wet seasons CP averaged 94 and 100 g/kg, and the DMD 0.591 and 0.601. The control treatment heifers lost 30 and 32 kg LW during the late dry seasons, and gained 143 and 136 kg during the wet, wet-dry transition and early dry seasons of Drafts 1 and 2, respectively. F.NIRS predicted the daily weight gain (DWG) of the heifers with accuracy useful for management purposes except during the early wet season of Draft 2 when intermittent rains increased diet quality but were insufficient for substantial pasture growth. The urea supplement reduced (P<0.01) heifer LW loss during the dry seasons, but much of this benefit subsequently disappeared due to compensatory growth; net benefit of the urea supplement over the annual cycle was 24 and 14 kg in the 2 drafts. This study demonstrated the capacity of F.NIRS to estimate the diet selected, liveweight change and liveweight responses to a N supplement in grazing cattle. Crown Copyright © 2010.
Dickinson G.R.,Agri Science Queensland |
Dickinson G.R.,University of The Sunshine Coast |
Lee D.J.,University of The Sunshine Coast |
Wallace H.M.,University of The Sunshine Coast
Annals of Botany | Year: 2012
Background and AimsCorymbia species from different sections hybridize readily, with some of increasing economic importance to plantation forestry. This study explores the locations of reproductive barriers between interspecific Corymbia hybrids and investigates the reproductive success of a wide taxonomic range of C. torelliana hybrid crosses. MethodsPollen, pistil and embryo development were investigated for four C. torelliana crosses (×C. torelliana, ×C. citriodora subsp. citriodora, ×C. tessellaris and ×C. intermedia) using fluorescent and standard microscopy to identify the locations of interspecific reproductive isolating barriers. Corymbia torelliana was also crossed with 16 taxa, representing six of the seven Corymbia sections, both Corymbia subgenera and one species each from the related genera, Angophora and Eucalyptus. All crosses were assessed for capsule and seed yields. Key ResultsInterspecific C. torelliana hybridization was controlled by pre-zygotic reproductive isolating barriers inhibiting pollen adhesion to the stigma, pollen germination, pollen tube growth in the style and pollen tube penetration of the micropyle. Corymbia torelliana (subgenus Blakella, sect. Torellianae) was successfully hybridized with Corymbia species from subgenus Blakella, particularly C. citriodora subsp. citriodora, C. citriodora subsp. variegata, C. henryi (sect. Maculatae) and C. tessellaris (sect. Abbreviatae), and subgenus Corymbia, particularly C. clarksoniana and C. erythrophloia (sect. Septentrionales). Attempted intergeneric hybrids between C. torelliana and either Angophora floribunda or Eucalyptus pellita were unsuccessful. ConclusionsCorymbia hybrids were formed between species from different sections and subgenera, but not with species from the related genera Angophora or Eucalyptus. Reproductive isolation between the interspecific Corymbia hybrid crosses was controlled by early- and late-acting pre-zygotic isolating barriers, with reproductive success generally decreasing with increasing taxonomic distance between parent species. These findings support the monophyly of Corymbia and the close relationships of infrageneric clades. The hybridizing propensity of Corymbia species provides opportunities for breeding but suggests risks of environmental gene flow. © The Author 2012. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved.
Daglish G.J.,Agri Science Queensland |
Nayak M.K.,Agri Science Queensland
Insect Science | Year: 2012
The potential for using imidacloprid (a neonicotinoid) and indoxacarb (an oxadiazine) as grain protectants was investigated in bioassays against resistant strains of five stored grain beetles. The species investigated were Rhyzopertha dominica (F.) (the lesser grain borer), Sitophilus oryzae (L.) (the rice weevil), Tribolium castaneum (Herbst) (the rust-red flour beetle), Oryzaephilus surinamensis (L.) (the saw tooth flour beetle), and Cryptolestes ferrugineus (Stephens) (the flat grain beetle). Each of these species has developed resistance to one or more protectants, including organophosphorus insecticides, synthetic pyrethroids and the juvenile hormone analogue methoprene. Mortality and reproduction after a 2-week exposure of adults to treated wheat depended on species, dose and insecticide. Imidacloprid had no effect on S. oryzae at any dose, but none of the other species produced any live progeny at 10 mg/kg. Indoxacarb had no effect on T. castaneum at any dose, but none of the other species produced any live progeny at 5 mg/kg. The results show that although both imidacloprid and indoxacarb can control at least four of the five key pests tested at doses comparable to those used for organophosphorus protectants, more potent neonicotinoid or oxadiazine insecticides would be needed than either of these to provide broad spectrum protection of stored grain. © 2011 The State of Queensland (Department of Employment, Economic Development and Innovation) Journal compilation © Institute of Zoology, Chinese Academy of Sciences.
Kay I.R.,Agri Science Queensland
Australian Journal of Entomology | Year: 2010
Sceliodes cordalis, eggfruit caterpillar, is an important pest of eggplant in Australia but little information was available on its biology. This study was conducted to determine the effect of temperature on the development on eggplant of eggs, larvae and pupae. Insects were reared at five constant temperatures from 20.5°C to 30.5°C with a 12:12 L : D photoperiod and the thermal summation model was fitted to the developmental rate data. Developmental zeroes and thermal constants of 11.22°C and 61.32 day-degrees for eggs, 12.03°C and 179.60 day-degrees for larvae, and 14.43°C and 107.03 day-degrees for pupae were determined. Several larvae reared at 20.5°C entered diapause. © 2010 The Author. Journal compilation © 2010 Australian Entomological Society.
Hayward A.C.,University of Queensland |
Pegg K.G.,Agri Science Queensland
Australasian Plant Pathology | Year: 2013
In 1955 a severe wilt disease occurring on ginger in the Near North Coast district of Queensland was incorrectly attributed to infection by a Fusarium sp., and later shown to be caused by a strain of Ralstonia solanacearum, now reclassified as R. sequeirae. The disease was brought from China into Australia on latently infected rhizomes, and possibly also with associated soil. Several DNA-based diagnostic methods have shown that the pathogen causing bacterial wilt of ginger in parts of China is indistinguishable from the pathogen uniquely associated with the disease in Queensland. © 2012 Australasian Plant Pathology Society Inc.