Action plan for controlling Amaranthus palmeri in maize fields of Aragón (Spain): An economic assessment under uncertainty

Societal Impact Statement Invasive weeds pose a global challenge to sustainable agriculture, threatening productivity while increasing the costs and uncertainty of crop management. Using 6 years of experimental evidence, we developed and evaluated three 10‐year action plans for controlling Amaranthus palmeri in maize crops in Aragón, Spain, accounting for biological and control‐effectiveness uncertainty. We found that economic outcomes depend on infestation levels and control effectiveness: High‐infestation scenarios generally remain profitable, whereas low but persistent infestations generate greater economic uncertainty. Short‐cycle systems are more resilient to management errors. These findings can help farmers and public authorities design adaptive control programs and allocate resources efficiently. Summary The spread of A. palmeri presents a serious threat to Spanish agriculture because of its remarkable adaptability and the substantial economic losses inflicted in affected areas. Despite the severe impact of this weed, limited information exists on the economic losses associated with the control measures that farmers could implement and the public expenditures incurred. This study aims to develop an action plan tailored for controlling A. palmeri under the maize cropping conditions in Aragón (Spain), while calculating the associated private and public costs. Based on the results of 6 years of field and laboratory experiments, we propose three distinct action plans over a 10‐year timeframe: one targeting fields with high infestation and two focusing on short‐ and long‐cycle maize. We evaluated the proposed action plans from an economic perspective, calculating the expected net present value (NPV) under three contexts: deterministic conditions, biological uncertainty, and control‐effectiveness uncertainty. The results reveal that in high‐infestation scenarios, most strategies maintain positive and stable profitability, providing strong economic security. Under low but persistent infestations, profitability is highly sensitive to both biological uncertainty and the effectiveness of control implementation. In short‐cycle systems, economic outcomes are more resilient, allowing the system to absorb management errors without compromising viability, which helps explain farmers' preference for these strategies. This is the first study in Europe to use experimental data to evaluate the economic impacts of A. palmeri , providing farmers and authorities with the essential information they need to design and adapt their control programs in uncertain contexts.