Browsing by Author "Robertson, LN"

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A metarhizium-based product for control of cane pests : SRDC final report BSS134
(BSES, 2000) Samson, PR; Robertson, LN; Milner, RJ; Bullard, GK
The fungus Metarhizium anisopliae is a naturally occurring pathogen of soil insects in Australia. Metarhizium can be used as a bioinsecticide for control of canegrubs by mass-producing spores on rice and applying the resulting product into canefields. Numbers of greyback canegrub in plant cane have been consistently reduced by more than 50% when spores of isolate FI-1045 together with the rice medium have been applied at 33 kg/ha. About 18 t of this product were applied in semi-commercial trials in 1997-1999. The product was registered as BioCane™ Granules in March 2000. FI-1045 has also given some control of southern one-year canegrub. Another isolate, FI-147, significantly reduced numbers of negatoria canegrub the year after application into sugarcane ratoons, and increased cane yield. The same isolate was equally effective against French's canegrub in laboratory bioassays, and field trials are in progress against this pest. Trials have been less successful against Childers canegrub, and more effective isolates must be identified for this species. Trial results have been very poor against soldier fly; none of the isolates tested in bioassays was very virulent, and no further work is planned.
Effect of funnel ants on eleven commercial clones of sugarcane at Tully
(BSES, 1996) Robertson, LN
Funnel ant activity was independent of cane clone, suggesting that there is no resistance to funnel ants in the commercial clones tested. The clones Q107 and Q117 performed poorly in the presence of funnel ants, a phenomenon also seen on infested farms throughout the Tully district. Q138 was confirmed as a variety able to produce high yields despite funnel ant infestation. H56-752 was a consistent high producer throughout the three years of the trial. Q124 and Q120 also peformed relatively well, despite Q120 being previously listed as susceptible to damage by funnel ants. The soil type at the trial site was a recent alluvium
Effects of natural enemies on soldier fly (Inopus rubriceps) populations in Queensland
(BSES, 1983) Robertson, LN
A study was initiated in 1981 to determine the role of natural enemies of soldier fly in south east Queensland. The objective of this work was to gain an understanding of soldier fly population dynamics in its native range. This paper presents information from a survey conducted to assess the degree of predation, parasitism and disease in soldier fly populations in Queensland. Intensive studies of natural enemies and population dynamics in south east Queensland are still in progress and will be reported in detail at a later date.
Field Evaluation of Aggregation Pheromones for Mass-Trapping of Cane Weevil Borer
(BSES, 1997) Robertson, LN; Giblin-Davis, RM; Oehlschlager, AC; Gries, R
Sugarcane weevil borer, Rhobdoscelus obscurus (Boisduval) (Coleoptera: Curculionidae: Rhynchophorinae), is native to Papua New Guinea, but was accidentally introduced to Queensland, Hawaii and Fiji with imported sugarcane material in the late 1800x (Veitch 1917). the larval stage is a serious pest of commercial sugarcane in those countries, and is also a minor pest of palms in queensland (Halfpapp and Storey 1991). Males of several species of Rhynchophorinae are known to produce pheromones which attract both males and females (Giblin-Davis et al. 1996.) Chang and Curtis (1972) first showed that males of R. obscurus release a pheromone after feeding on fermenting sugarcane. Fermenting sugarcane is also attractive to R. obscurus (Bell 1937). The aggregation pheromones of several species of Rhynchophorinae have been chemically identified and synthesised. Oehlschlager et al. (1995) has tested synthetic rhynchophorol as a method of removal trapping of the palm weevil, Rhynchophorus palmarum (L.), in oil palm plantations in Costa Rica.
Field Experiments to Optimise Lures for Mass-Trapping of Cane Weevil Borer
(BSES, 1998) Robertson, LN; Giblin-Davis, RM; Oehlschlager, AC
Cane weevil borer, Rhobdoscelus obscurus (Biosduval) (Coleoptera: Curculionidae: Rhynchophorinae), is an introduced pest of sugarcane in Queensland, Hawaii and Fiji. It was accidentally introduced from Papua New Guinea about 1900 with sugarcane planting material (Veitch 1917). Previous research showed that male cane weevil borers produce aggregation pheromones which attract both male and female cane weevil borers. Three compounds emitted by feeding males were identified by Dr R Gries ata Simon Fraser University (see Robertson et al 1997). These compounds were synthetically produced by ChemTica Internacional SA and two of these, 2-methyl-4-octanol and 6-methyl-2-hepten-4-ol (rhynchophorol), were shown to be the active compounds for attracting cane weevil borer (Robertson et al 1997). The experiments reported here were designed to determine the optimum ratio of the two active compounds to attract cane weevil borer. In addition, the relative attractiveness of they synthetic lures was compared with that produced by feeding male cane weevil borers. Finally, a chemical known to increase trap catches of other species of Rhynchophorinae, ethyl acetate (marketed as 'Weevil Magnet'), was tested for its ability to synergise the attractiveness of the aggregation pheromones.
Key factors in control of Greyback Canegrub populations : SRDC final report BS120S
(BSES, 1998) Robertson, LN; Dall, DJ; Lai-Fook, J; Kettle, CG; Bakker, P
Greyback canegrub outbreaks with severe losses in sugar production have persisted for more than six years in the Burdekin district, but population densities of the pest have declined at locations in the Herbert Valley, Tully and Innisfail districts over the same period. Six species of pathogenic organism were found to cause disease and death of greyback canegrubs, with relatively high incidence in grubs collected from the Herbert Valley, Tully and Innisfail study sites, but low incidence in the Burdekin. No deaths from entomopathogenic diseases were recorded in 226 grubs examined from the Burdekin in 1998. Two microorganisms, Adelina sp (Protozoa: Coccidia), and Metarhizium anisopliae (Deuteromycetes fungi), were the most prevalent pathogens in far north Queensland grub populations. Incidence of Adelina sp. alone accounted for 55-64 % of the variance in mortality of grubs recorded from samples collected across all locations in 1994 and 1995. The initial objectives of this SRDC funded study were to study dispersion of greyback canegrubs in the soil profile and devise a sampling program to estimate population density with known precision; monitor population density of greyback adults, eggs and larvae; identify mortality factors which act on each life stage including climate, natural enemies and farming practices; determine key factors which control greyback population changes and suggest ways to suppress population growth; develop model which predicts changes in greyback populations. Following a review in April 1995 the project was expanded to encompass the following additional objectives; assess the effects of crop management strategies on frequency of occurrence of diseases in greyback canegrubs; demonstrate pathogenicity of selected microorganisms to greyback grubs; determine dose/response relationships (ie infectious dose, time to death, effects on larval feeding and growth); attempt small-scale in vitro culture of selected microorganisms which display pathogenicity to grubs.
Promotion of integrated pest management in sugarcane: Final report BS184
(1998) Halvorsen, L; Robertson, LN
Associate Professor and agricultural science writer Lisa Halvorsen was invited to work with the Bureau of Sugar Experiment Stations for five months. Her aim was to help develop effective communications strategies for disseminating information on integrated pest management (IPM) and related areas through the media and other outlets, as well as to produce extension-type written materials. Professor Halvorsen was on sabbatical from the University of Vermont Extension System, and had previous experience of promoting IPM including in queensland cropping systems. She worked with extension officers and researchers at all five BSES research stations from Meringa to Bundaberg, lending communications support in four areas: writing/editing, instruction/consultation, media relations, and marketing. Specific projects undertaken were dependent on the needs and interest of personnel at each station.
Statewide adoption of best irrigation practices for supplementary and full irrigation districts : SRDC Final report BS183S
(2000) Robertson, LN; Giblin-Davis, RM; Oehlschlager, AC; Gries, R
Project BS183S has researched and identified a number of means by which on-farm water use efficiency may be improved. These include the use of irrigation scheduling devices, improved furrow irrigation design and management, and use of modelling tools by local extension staff.Field trials demonstrated that deep drainage losses associated with furrow irrigation can be reduced by the use of surge irrigation and improved furrow irrigation management. Use of the furrow irrigation simulation model SIRMOD has enabled advisory staff to measure and optimise furrow irrigation events under typical sugar growing conditions. Difficulties however remain with deep drainage losses from furrow irrigation under trash blankets. Capacitance soil moisture meters and tensiometers were demonstrated to be effective tools for scheduling sugarcane irrigation. These devices enable growers to time irrigations to minimise crop water stress. APSFront~Sugar was developed in conjunction with APRSU to enable local advisory staff to investigate a range of issues related to sugarcane production. Despite difficulties with high rainfall, field trials demonstrated that in the absence of watertables APSIM produced reasonable predictions of crop yield. APSIM was employed to determine effective rainfall, crop response to irrigation, water use efficiency and irrigation requirement for the Mackay, Bundaberg, Mareeba, Proserpine, Atherton, Childers, and Sarina districts. APSIM was also able to identify a number of improved strategies for the use of limited allocation in supplementary irrigation districts. Project BS183S provided considerable training and support to research and extension staff.