| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 4507186 | Crop Protection | 2007 | 10 Pages |
As part of the development of an integrated pest management (IPM) concept in the Sahel an ecological model of the population dynamics of Oedaleus senegalensis was developed. The model has been used to develop different elements of an IPM strategy, both optimising time and place of treatment, and combining or replacing the use of chemical insecticides with the use of the fungal control agent Metarhizium anisopliae. M. anisopliae is hypothesised to be most effective as a preventive measure whereas chemical insecticides will be most effective in curative treatments. Simulations of the efficacy of the two agents with different treatment strategies were made, and long-term effects of the two products were examined by making simulations across 2 years. Results show that M. anisopliae is not capable of reducing the relative yield loss to a greater extent than insecticides neither the first year nor the second. The application of M. anisopliae was found to be most effective against first generation nymphs in southern Senegal and against second-generation grasshoppers in Northern Senegal, where the efficacy equalled the use of chemical insecticides. A benefit/cost-analysis showed that the most effective strategy is a combination of treatment with M. anisopliae in southern Senegal in the start of the season with application of insecticide when a threshold value of 40 grasshoppers m−2 is exceeded. This strategy is most effective in minimising yield loss and securing the overall as well as the local millet production. To be cost effective the strategy has to be applied each year. A new finding is, that the results also showed it to be cost effective to treat grassland.
