Debbie Rae

... Treatment means were separated using Ryan's Q test if the assumption of equality of variance was met or Dunnett T3-test if the assumption was ... In Experiment 1 sprays were applied using a 3500 Silvan airblast unit with Radak conveyers specially designed for spraying olives. ...

The Australian Assistance in Development organisation (AusAID) funded three projects over the last ten years as part of the Collaboration for Agriculture and Rural Development Program (CARD) with the initial objective to introduce Integrated Pest Management (IPM) based on mineral spray oil into citrus production in Vietnam. This objective later evolved from IPM to a broader Integrated Crop Management (ICM) approach and eventually to the introduction of procedures for Good Agricultural Practice (GAP). In this paper we discuss the evolution of the collaborative approaches in the consecutive projects, departing from making Vietnamese researchers introduce a preconceived, externally developed concept in their local socio‐economic and natural environments, to gradually facilitating the local partners to review potential innovations, test and adapt them, and develop management systems that suit the local conditions. This process resulted in linkages and interactions amongst local and inte...

Nitrogen levels in commercial plots of sugarcane varied over the cane-growing season. However, when adjusted for seasonal effects, nitrogen did not have a detectable effect on the size of mealybug populations on cane. In laboratory experiments, the survival of immature Saccharicoccus sacchari and the size attained at the onset of the oviposition period was influenced by the level of nitrogen fertiliser applied to potted sugarcane. Survival of S. sacchari increased to a maximum at 320 mg L-1 soluble nitrogen in sugarcane and decreased at higher levels, while size increased with increased nitrogen over the whole range of concentrations tested. Nitrogen-driven changes in the abundance of S. sacchari predicted from laboratory data indicate that normal variations in nitrogen concentrations of field-grown sugarcane have little effect on the population dynamics of S. sacchari.

Generation time of S. sacchari females reared on potted cane ranged from 107 days at 20-degrees-C to 25 days at 30-degrees-C. Three models were fitted to developmental data. The linear model indicated a minimum threshold temperature of 17-degrees-C and the inverse polynomial model a maximum development rate at 30.4-degrees-C. Developmental response to temperature varied from that previously reported in Egypt and the Philippines. The largest and most fecund females were produced at 30-degrees-C. Net reproductive rate varied from 82.0 and 79.7 at 20 and 33-degrees-C respectively to 205.5 at 30-degrees-C. The intrinsic rate of natural increase (r(m) increased from 0.038 at 20-degrees-C to 0.186 at 30-degrees-C. The value of the common shape parameter of the Weibull distribution used to describe adult survivorship curves was 3.5, indicating type I survivorship curves. The ovipositional threshold (V0) was estimated as 16.5-degrees-C. The rate of development of individuals had a major inf...