The Thap Muoi district in Dong Thap province, Vietnam, is renowned as the largest rice producer, cultivating 112,762 hectares and specialising in three rice crops per year, with some areas achieving 3.5 annual crops. However, changing farming practices, low-quality rice seeds, and mechanisation have led to the emergence and spread of weedy rice (Oryza spp.) in Thap Muoi and the broader Mekong delta...