Browsing by Author "Oehlschlager, AC"

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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.
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.