Browsing by Author "Prinsloo, Philip"

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    The development of an Eldana Risk Index
    (Stellenbosch : Stellenbosch University, 2024-03) Prinsloo, Philip; Potgieter, Linke; Nel, Hannelie; Stellenbosch University. Faculty of Economic and Management Sciences. Dept. of Logistics.
    ENGLISH SUMMARY: The South African sugarcane industry faces significant challenges due to declining global sugar demand, a trend triggered by national government taxation of the sugar industry, consumer product regulations, and the need to address productivity losses caused by several pest species such as the African stem borer, Eldana saccharina Walker (Lepidoptera: Pyralidae). Numerous mathematical models have been developed to investigate the population dynamics of this pest species and to improve pest control strategies through biological control, the release of sterile insects, and the use of genetically modified sugarcane containing insecticidal genes from the bacterium, Bacillus thuringiensis (Bt) sugarcane. Additionally, detailed mechanistic sugarcane growth models are employed by the industry to predict yields based on climatic factors. However, an integrated framework that links sugarcane growth models with Eldana saccharina population dynamics models has not yet been established. Such a framework would enhance decision support for pest management by providing a more integrated view of the sugarcane agroecosystem. This study proposes an Eldana Risk Index (ERI) model as a decision support tool. Building on previous research, this model integrates output from sugarcane crop models with Eldana saccharina population growth models through seasonally integrated risk profiles. The ERI model’s primary structure includes two main dimensions, assessed daily by combining outputs from the sugarcane growth model CaneSim®, weather data, and an Eldana saccharina population growth model adapted from previously developed models. The first dimension focuses on sugarcane, encompassing factors such as temperature, water stress related to cane health, susceptibility to infestation, and damage due to infestation. The second dimension focuses on risks associated with Eldana saccharina, encompassing the effects of temperature on pest abundance, the stress of insect desiccation, and the influence of temperature and precipitation on insect desiccation and mortality due to temperature. The ERI model presents an interdisciplinary approach for quantifying infestation risks in the sugarcane industry, thereby offering improved decision support for integrated pest management. Additionally, this study seeks to underscore various opportunities in applying real-time pest abundance methods and technologies. These advancements aim to further augment the effectiveness of integrated pest management strategies, particularly against insects such as Eldana saccharina.