Smut grass (Sporobolus indicus) chemical control: a systematic review

Abstract This systematic review evaluated studies published between 1980 and 2025 on the chemical control of smut grass [ Sporobolus indicus (L.) R. Br.] in the Americas, with a focus on pastures. After 446 publications were screened, 13 peer-reviewed articles met the inclusion criteria. Most studies were conducted in the subtropical United States, particularly in Florida, on bahiagrass ( Paspalum notatum Flueggé) pastures, with only one study carried out in Brazil. The most frequently reported herbicide was hexazinone, present in more than 80% of the studies, applied either alone or in combination with mechanical methods or fertilization. Consistent results indicated control efficacy above 85%, especially at doses ≥0.84 kg ha⁻ 1 and when applied during summer. Selectivity for use in bahiagrass was considered satisfactory despite temporary phytotoxic symptoms. Integrated strategies, such as herbicide applications combined with nitrogen fertilization, showed potential to restore forage dominance and reduce reinfestation. Other herbicides, such as glyphosate, indaziflam, imazapic, mesotrione, and triazines, were less frequently investigated. Indaziflam, applied preemergence, caused a significant reduction in the seedbank, showing promise for preventive management, given the high dormancy and longevity of S. indicus seeds. The integration of chemical and mechanical control produced variable outcomes: in some cases, mowing before application reduced efficacy, whereas in others, when associated with strategies to remove growing points and subsequent herbicide application, it enhanced control. The scarcity of studies under Brazilian and other tropical or subtropical conditions limits the understanding of this species’ adaptation and the efficiency of management methods across different edaphoclimatic contexts. Expanding research in these regions is crucial for developing effective and sustainable management strategies.