Modeling smallholder agricultural systems to manage Striga in the semi-arid tropics

Across southern Africa (SA), significant maize yield losses are attributed to invasive and parasitic weeds. Abundance of Striga (Striga asiatica) has become more frequent in smallholder farms (<2 ha) the past decade. Various control practices (SCPs) have been disseminated across SA, yet often, without decision support tools inform extension officers researchers which ones most appropriate for contexts. System dynamics modeling (SDM) provides an opportunity evaluate efficacy SCPs multiple seasons different agroecosystems their associated environments. We developed a SDM long-term four popularly used maize-based cropping systems. Observations from studies outlining local soil seedbanks, emergence flowering rates farmer fields were calibrate SDM. Model simulations indicate that while combination necessary manage weed, future research should focus on developing smallholder-adapted address attachment stage weed's lifecycle (e.g., timely manure application) rather than its germination, or stages. Given devastating effects S. asiatica had food security Malawi it is imperative develop like systems models smallholders. Models do not capture underlying mechanisms driving infestations may provide with potentially misleading information, subsequently, delivery ineffective SCPs.