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Understanding Spodoptera litura larval survival in Bollgard 3 crops in Northern Australia
No full textThe introduction of Bt cotton has facilitated industry expansion into regions historically burdened by high insect populations. Since experimental farming of Bollgard 3 commenced in Northern Australia in 2017, there have been frequent reports of S. litura larvae of all instar sizes surviving in some crops. Effective pest and resistance management relies on a comprehensive understanding of pest biology, ecology and host-plant interactions. However, due to its rarity in Australia's temperate climates, little is known about S. litura, hindering the development of sustainable management practices. Investigating factors associated with larval survival in Bollgard 3 crops marks the initial step in assessing the pest status and resistance risks posed by S. litura in co on across Northern Australia. Here we discuss a series of experiments exploring various mechanisms that potentially facilitate improved larval survival, including plant phenology and different plant parts
Starving soil microbes: consequences to cotton plant and soil health.
No full textSoil biological health plays an important role in functions related to nutrition, health and productivity of Australian cotton crops. Surface soils in cotton growing regions are generally low in organic carbon levels hence C inputs from roots and crop residues are important sources of energy for soil biota. Effects of fallow as part of rota on in cotton systems on soil biological and chemical properties: microbial biomass (MB), microbial activity, diversity (gene c and catabolic) and disease suppression potential were investigated to determine consequences to plant and soil health in multi-year field experiments and farmer fields over multiple seasons. MB-C levels generally ranged between 100 - 600 µg C/g soil and >90% of cotton soils have microbial quotient values <5%, an attainable threshold for agricultural soils. Soils from the Fallow-Co on rota on generally showed significantly lower MB (the ‘engine’ for all biological functions), abundances of total fungi and bacteria, specific groups of beneficial bacteria, microbial catabolic and genetic diversity of bacteria and fungi and pathogen suppression potential thereby weakening the biological buffer compared to that under other rotations including continuous Cotton.
Overall, these results suggest that non-crop periods as part of cotton rota on system should be considered not only for their impacts on plant pathogens but also on MB and beneficial microbial communities to manage the health of cotton plants and soils
National Mungbean Improvement Program - 2016 to 2021 - Southern Queensland Yield and Quality Data
No full textNMIP evaluates grain yield from three levels of yield trials sown at a maximum of 8 field trials from 6 locations in any one season. Two locations in each of the major growing regions are represented, two in Southern Queensland (Warra and Warwick).
A small KEW belted front header is used to harvest either 2 row or 4 row plots from 6-10m in length. All maturity ranges are present in any one trial with up to two trials per year grown under irrigation at Warwick
Developing a push-pull semiochemical pest management strategy for control of “Ips grandicollis” (Coleoptera:Curculionidae: Scolytinae) in pine plantation
No full text“Ips grandicollis” (Eichhoff) (Coleoptera: Curculionidae: Scolytinae) is an invasive pine pest in Australia and is native to eastern USA. It transfers symbiotic fungi that block conducting tissues and reduce the commercial value of wood by causing blue staining. Conspecific aggregation pheromones and host volatiles induce attraction (pull), whereas semiochemicals from sympatric species and non-host plants may induce an anti-aggregation (push) response. By identifying and using these chemical messages, we aim to develop semiochemical-based pest-control techniques for forest protection
Clarification of ambiguous genus records for Australian Cleridae (Coleoptera: Cleroidea)
No full textThe status of the genera Balcus Sharp, Gastrocentrum Gorham, Korynetes Herbst, Solervicensia Barr, Monophylla Spinola and Thanasimus Latreille in Australia is assessed based on review of dubious or ambiguous published Australian records of the following species-group taxa: Balcus violaceus (Fabricius), a New Zealand species listed as Australian by Schenkling (1906); Gastrocentrum dux (Westwood), described from Australia by Westwood (1853); Korynetes abdominalis (Fabricius), an Indian species listed as Australian by Schenkling (1906); Korynetes coeruleus (De Geer), a Palearctic species with a synonym, Corynetes unicolor Chevrolat, 1876, described from Australia; Monophylla terminata (Say), a North American species with a synonym, Elasmocerus picticollis Blackburn, 1901, described from Australia; Solervicensia ovata (Spinola), a South American species with two synonyms (one newly proposed) described from Australia, viz. Labasiella duboulayi Pic, 1950, and Korynetes nigrosignatus Pic, 1941 new synonym; and Thanasimus dubius (Fabricius), a North American species introduced to Australia for the biological control of Ips grandicollis (Eichhoff) (Scolytinae). All six of the abovementioned genera are deemed absent from Australia due to the lack of evidence for the occurrence of representative species within the Australian political region
Fungal Planet description sheets: 1550–1613
No full textNovel species of fungi described in this study include those from various countries as follows: Argentina, Neocamarosporium halophilum in leaf spots of Atriplex undulata. Australia, Aschersonia merianiae on scale insect (Coccoidea), Curvularia huamulaniae isolated from air, Hevansia mainiae on dead spider, Ophiocordyceps poecilometigena on Poecilometis sp. Bolivia, Lecanora menthoides on sandstone, in open semi-desert montane areas, Sticta monlueckiorum corticolous in a forest, Trichonectria epimegalosporae on apothecia of corticolous Megalospora sulphurata var. sulphurata, Trichonectria puncteliae on the thallus of Punctelia borreri. Brazil, Catenomargarita pseudocercosporicola (incl. Catenomargarita gen. nov.) hyperparasitic on Pseudocercospora fijiensis on leaves of Musa acuminata, Tulasnella restingae on protocorms and roots of Epidendrum fulgens. Bulgaria, Anthracoidea umbrosae on Carex spp. Croatia, Hymenoscyphus radicis from surface-sterilised, asymptomatic roots of Microthlaspi erraticum, Orbilia multiserpentina on wood of decorticated branches of Quercus pubescens. France, Calosporella punctatispora on dead corticated twigs of Acer opalus. French West Indies (Martinique), Eutypella lechatii on dead corticated palm stem. Germany, Arrhenia alcalinophila on loamy soil. Iceland, Cistella blauvikensis on dead grass (Poaceae). India, Fulvifomes maritimus on living Peltophorum pterocarpum, Fulvifomes natarajanii on dead wood of Prosopis juliflora, Fulvifomes subazonatus on trunk of Azadirachta indica, Macrolepiota bharadwajii on moist soil near the forest, Narcissea delicata on decaying elephant dung, Paramyrothecium indicum on living leaves of Hibiscus hispidissimus, Trichoglossum syamviswanathii on moist soil near the base of a bamboo plantation. Iran, Vacuiphoma astragalicola from stem canker of Astragalus sarcocolla. Malaysia, Neoeriomycopsis fissistigmae (incl. Neoeriomycopsidaceae fam. nov.) on leaf spots on flower Fissistigma sp. Namibia, Exophiala lichenicola lichenicolous on Acarospora cf. luederitzensis. Netherlands, Entoloma occultatum on soil, Extremus caricis on dead leaves of Carex sp., Inocybe pseudomytiliodora on loamy soil. Norway, Inocybe guldeniae on calcareous soil, Inocybe rupestroides on gravelly soil. Pakistan, Hymenagaricus brunneodiscus on soil. Philippines, Ophiocordyceps philippinensis parasitic on Asilus sp. Poland, Hawksworthiomyces ciconiae isolated from Ciconia ciconia nest, Plectosphaerella vigrensis from leaf spots on Impatiens noli-tangere, Xenoramularia epitaxicola from sooty mould community on Taxus baccata. Portugal, Inocybe dagamae on clay soil. Saudi Arabia, Diaporthe jazanensis on branches of Coffea arabica. South Africa, Alternaria moraeae on dead leaves of Moraea sp., Bonitomyces buffelskloofinus (incl. Bonitomyces gen. nov.) on dead twigs of unknown tree, Constrictochalara koukolii on living leaves of Itea rhamnoides colonised by a Meliola sp., Cylindromonium lichenophilum on Parmelina tiliacea, Gamszarella buffelskloofina (incl. Gamszarella gen. nov.) on dead insect, Isthmosporiella africana (incl. Isthmosporiella gen. nov.) on dead twigs of unknown tree, Nothoeucasphaeria buffelskloofina (incl. Nothoeucasphaeria gen. nov.), on dead twigs of unknown tree, Nothomicrothyrium beaucarneae (incl. Nothomicrothyrium gen. nov.) on dead leaves of Beaucarnea stricta, Paramycosphaerella proteae on living leaves of Protea caffra, Querciphoma foliicola on leaf litter, Rachicladosporium conostomii on dead twigs of Conostomium natalense var. glabrum, Rhamphoriopsis synnematosa on dead twig of unknown tree, Waltergamsia mpumalanga on dead leaves of unknown tree. Spain, Amanita fulvogrisea on limestone soil, in mixed forest, Amanita herculis in open Quercus forest, Vuilleminia beltraniae on Cistus symphytifolius. Sweden, Pachyella pulchella on decaying wood on sand-silt riverbank. Thailand, Deniquelata cassiae on dead stem of Cassia fistula, Stomiopeltis thailandica on dead twigs of Magnolia champaca. Ukraine, Circinaria podoliana on natural limestone outcrops, Neonematogonum carpinicola (incl. Neonematogonum gen. nov.) on dead branches of Carpinus betulus. USA, Exophiala wilsonii water from cooling tower, Hygrophorus aesculeticola on soil in mixed forest, and Neocelosporium aereum from air in a house attic. Morphological and culture characteristics are supported by DNA barcodes
Effect of Plant Essential Oil Formulations on Bemisia tabaci MEAM1 (Gennadius) and Its Parasitoid Eretmocerus hayati (Zolnerowich and Rose)
Get PDFSilverleaf whitefly (SLW), Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), consists of genetically diverse species known to cause significant destruction in many crops around the world. Nowadays, synthetic insecticides are a key component in the management of this pest. However, they also come with disadvantages, such as environmental pollution, pest resistance and recurrence, and toxicity to pollinators and natural enemies. Essential oils from aromatic plants and biocontrol agents may provide a new and safe alternative to synthetic chemicals. In this study, we assessed the lethal impact of three new plant essential oil formulations (referred to as F1, F2, and F3) against the developmental stages of B. tabaci and its parasitoid Eretmocerus hayati (Zolnerowich and Rose) (Hymenoptera: Aphelinidae). The tested formulations consisted of combinations of mustard oil and different surfactants. The formulations were effective against the eggs and nymphal stages of B. tabaci. At the highest concentration assessed (1.23%), F1 was the most effective formulation against the eggs, resulting in 85% mortality, whereas F2 was most effective against the nymphs (92.5% and 88.3% mortality for the young and old nymphs, respectively). However, adult mortality rates were below 40% for all the tested formulations. The range of median lethal concentration (LC50) values was between 0.65 and 1.05% for B. tabaci. The side effects of the three formulations were assessed against E. hayati, treated as parasitized nymphs of B. tabaci. At the highest tested concentration (1.23%), F2 and F3 resulted in 80% and 70% mortality of the parasitoids, respectively (classified as moderately or slightly harmful according to the IOBC), whereas F1 resulted in 17.5% mortality. As F1 was effective against SLW with minimal effects on the parasitoid, it is the most suitable formulation of those tested for use in an integrated pest management (IPM) program targeting the younger life stages of B. tabaci
The Effects of Atrazine, Diuron, Fluazifop-P-butyl, Haloxyfop-P-methyl, and Pendimethalin on Soil Microbial Activity and Diversity
Get PDFUnderstanding the impacts of herbicides on soil microbial communities is important, as these organisms mediate a wide range of ecosystem services. Here, we investigated whether the diversity and function of soil microbial communities were significantly influenced by one-off applications of atrazine, diuron, fluazifop-P-butyl, haloxyfop-P-methyl and pendimethalin as pure compounds at their recommended doses over multiple time points (1, 3, 7, 14, 30 and 60 days). Phylogenetic marker gene sequencing revealed that none of the herbicides influenced the numbers of bacterial and archaeal taxa or the evenness of their abundances. Similarly, none of the herbicides influenced the composition of bacterial and archaeal communities, except for diuron, fluazifop-P-methyl and pendimethalin, which were associated with larger relative abundances of a small number of OTUs on day 30 only. Functionally, none of the herbicides significantly influenced fluorescein diacetate hydrolysis (FDA) and beta-glucosidase activities or the induced respiratory responses of soil microbial communities to a range of substrates. These data indicate that the active herbicide ingredients tested may have minimal non-target effects when applied once at their recommended dose. Given their frequent use, it is important to next consider whether these herbicides have more pronounced effects at higher doses and application frequencies
Rapid assessment of soil carbon and nutrients following application of organic amendments
No full textRegular and routine soil analysis is vital to properly understand agricultural soil evolution and sustainably manage nutrient applications over time. Hyperspectral imaging (HSI) is a fast-emerging technology and has shown potential to rapidly detect soil nutrient levels. However, it remains unknown to what extent processing soil samples and applying organic amendments, such as biochar, to soil will affect HSI model prediction accuracy and reliability. This study aimed to: 1) compare prediction accuracy of models developed using images of sieved and ground soils; and 2) assess prediciton reliability for samples where biochar had been applied. Specifically, we developed partial least squares regression (PLSR) models to predict soil total carbon (TC), nitrogen (TN), water extractable phosphorus (P), potassium (K) and sodium (Na) using pooled data collected over six years. Additionally, prediction reliability using best-fit models for samples with nil biochar were compared to samples where biochar was applied. Best-fit PLSR models were developed using images of ground soils and improved prediction of TN (R2p from 0.78 to 0.84; ratio of performance deviation (RPD) from 1.74 to 2.37) and Na (R2p from 0.78 to 0.83; RPD from 1.97 to 2.23) compared with using images of sieved soils. In general, prediction accuracy of TC, TN, P and Na was influenced by processing by grinding, whereas this was not the case for K. Images of ground soils predicted reference values more accurately due to reduced particle size and light scattering, resulting in increased mean reflectance and sample homogeneity. Biochar addition to individual samples did not impede prediction reliability in the external test dataset. Reliable TN and Na prediction occurred in 79.4% and 84.3% of samples containing biochar, and 73.7% and 78.4% with no biochar, respectively. Therefore, hyperspectral imaging represents a promising tool to rapidly predict nutrients in agricultural systems where organic amendments and biochar have been applied
Insecticide resistance management of Bemisia tabaci (Hemiptera: Aleyrodidae) in Australian cotton – pyriproxyfen, spirotetramat and buprofezin
Get PDFBACKGROUND: Bemisia tabaci is a globally significant agricultural pest including in Australia, where it exhibits resistance to numerous insecticides. With a recent label change, buprofezin (group 16), is now used for whitefly management in Australia. This study investigated resistance to pyriproxyfen (group 7C), spirotetramat (group 23) and buprofezin using bioassays and available molecular markers. RESULTS: Bioassay and selection testing of B. tabaci populations detected resistance to pyriproxyfen with resistance ratios ranging from 4.1 to 56. Resistance to spirotetramat was detected using bioassay, selection testing and sequencing techniques. In populations collected from cotton, the A2083V mutation was detected in three populations of 85 tested, at frequencies ≤4.1%, whereas in limited surveillance of populations from an intensive horticultural region the frequency was ≥75.8%. The baseline susceptibility of B. tabaci to buprofezin was determined from populations tested from 2019 to 2020, in which LC50 values ranged from 0.61 to 10.75 mg L−1. From the bioassay data, a discriminating dose of 200 mg L−1 was developed. Recent surveillance of 16 populations detected no evidence of resistance with 100% mortality recorded at doses ≤32 mg L−1. A cross-resistance study found no conclusive evidence of resistance to buprofezin in populations with high resistance to pyriproxyfen or spirotetramat. CONCLUSIONS: In Australian cotton, B. tabaci pest management is challenged by ongoing resistance to pyriproxyfen, while resistance to spirotetramat is an emerging issue. The addition of buprofezin provides a new mode-of-action for whitefly pest management, which will strengthen the existing insecticide resistance management strategy. © 2023 Commonwealth of Australia