Seed germination is pivotal for plant establishment and highly sensitive to environmental conditions. Understanding these processes aids in developing sound agronomic practices for Cyperus rotundus L., a cosmopolitan weed that holds dual significance as both a persistent agricultural challenge and a valuable source of medicinal and industrial raw materials. Experiments were conducted to investigate germination and emergence of C. rotundus seeds from two populations in response to diverse environmental factors. We found that germination/emergence characteristics were significantly influenced by environmental factors. Germination exhibited strong photoblastic response, being significantly stimulated by light while remaining negligible under continuous darkness. Optimal germination was achieved under an alternating temperature regime of 35/25°C, whereas germination ceased entirely at or below 10 °C. All populations exhibited over 68% germination across all pH levels, with higher rates in slightly acidic to neutral conditions. Germination was favored by low salinity and osmotic potential, showing a dose-dependent inhibition as salt concentration or moisture stress increased. Seed viability was near-completely lost after exposure to a high-temperature pretreatment of 115 °C for 5 min. Deep burial and residue mulch decreased emergence, whereas seedling emerged well at the soil surface. Overall, our findings offer practical frameworks for both the propagation and control of C. rotundus populations. To ensure successful establishment for economic or medicinal use, seeds should be sown at a depth of less than 0.5 cm in environments with favorable conditions, including light exposure and relatively high temperatures. Conversely, these results also provide a biological basis for weed control. Deep tillage or the application of heavy crop residue (e.g., 12 t ha − 1 ) can effectively reduce seedling emergence by creating physical barriers and blocking necessary light signals. Additionally, the high-temperature sensitivity of the seeds suggests that thermal treatments or soil solarization could be integrated into long-term management programs to effectively deplete the viable soil seed bank.
Meng et al. (Thu,) studied this question.