Simulating the population dynamics of barley grass (Hordeum spp.) and impacts of weed management strategies in a southern Australian lucerne (Medicago sativa) pasture

Context Barley grass (Hordeum spp. L.) is an annual, invasive weed of southern Australian crops and pastures, frequently associated with weight loss carcass damage in sheep due to its sharp seeds. Knowledge gaps exist regarding optimal density thresholds for effective control reduce impacts on animal production. The value integrated management (IWM) over individual options reducing barley populations pasture also unknown. Aims We aimed develop a model simulating the population dynamics within lucerne (Medicago sativa pastures Australia test hypothesis that combining herbicides mowing will be more removing seedbanks time than measures. Methods was developed Microsoft Excel adapted from other annual models. takes Monte Carlo approach simulate 10 years using five weed-control thresholds. It parameterised data recent experiments available literature. Key results most long-term strategy occurred threshold 5 seedlings m−2 by early late herbicide applications, mowing, seedbank 86% 89%, respectively. Conclusions Simulation showed IWM programs were years, particularly at low densities (≤50 m−2). Implications Incorporation this into bioeconomic grazing systems valuable determining economic strategies minimising effects seed contamination lamb production systems.