Estimating the Economic Cost of Fungicide Resistance in Crop Production

Epidemics of plant diseases, estimated to cause significant economic losses in crop production, have led to the widespread use of fungicides to control crop diseases. However, the evolution of fungicide resistance has resulted in substantial indirect costs, making it challenging to design economic policy for more sustainable use of fungicides. A recent study combined a spatially implicit mathematical model of crop epidemics with an economic analysis at the landscape scale to investigate the net economic return from a landscape and estimate the economic cost of fungicide resistance.

Key Takeaways:

• The study estimated that epidemics of plant diseases cause significant economic losses in crop production, highlighting the need for more sustainable use of fungicides.
• The evolution of fungicide resistance incurs substantial indirect costs, making it essential to estimate these costs reliably to inform economic policy.
• A spatially implicit mathematical model of crop epidemics combined with an economic analysis at the landscape scale was used to investigate the net economic return from a landscape.
• The study discovered a pattern of accelerating (or decelerating) returns, contrary to expected diminishing returns, in the net economic return from a landscape depending on the proportion of fungicide-treated fields.
• The economic cost of the evolution of fungicide resistance was calculated as the difference between the optimal net return of the landscape in the absence and presence of resistance.
• The cost of resistance evolution depends strongly on the fungicide price, the degree of resistance, the pathogen's basic reproduction number, and the yield loss due to disease.
• The study found that the cost of resistance evolution declines with the fungicide price and exhibits a non-monotonic pattern as a function of the basic reproduction number.
• Robust estimation of the cost of resistance evolution is essential to inform economic policy and encourage more sustainable use of fungicides.

Statistics:

• Estimated economic losses in crop production due to plant disease epidemics: not specified.
• Substantial indirect costs incurred due to evolution of fungicide resistance: not specified.
• Proportion of fungicide-treated fields: not specified.
• Optimal net return of the landscape in the absence of resistance: not specified.
• Economic cost of resistance evolution: depends on fungicide price, degree of resistance, pathogen's basic reproduction number, and yield loss due to disease.

Sources:

• biorxiv.org/content/10.1101/2023.09.05.556392v4