Biological characteristics of Leersia japonica (Makino) Honda and its implications for weed management.

BACKGROUND: Leersia japonica (Makino) Honda is a perennial weed and currently identified as a new dominant weed species in rice fields in many countries, including China. Here, we studied the biological characteristics combined with nonchemical management of L. japonica to develop a proper control strategy of this weed. RESULTS: The results showed that 33/28 °C in a 12 h:12 h, light:dark photoperiod were the most suitable growth conditions for seedling regeneration. Salt (NaCl) inhibits the regeneration of seedlings totally at a concentration of 51.3 mm. Seedlings of L. japonica could regenerate in a wide range of pH environments (from 3.50 to 9.50), endowing L. japonica with strong pH adaptability. Osmotic stress also inhibits the regeneration of seedlings totally at −0.13 MPa. A long dehydration time inhibits the regeneration of seedlings; no seedlings could be regenerated for 15 h. With low soil moisture content (33.3% and 50%), the regeneration rate and aboveground fresh weight (FW) were significantly lower than these with high soil moisture content (66.7% and 100%). Stem segments buried in the surface (0 cm) of soil could produce seedlings with the highest regeneration rate (37.5%) and seedling aboveground FW (0.64 g). As the soil depth increased, the regeneration rate and aboveground FW decreased significantly and no seedlings could be regenerated beyond 6.9 cm. CONCLUSION: Based on these biological characteristics of L. japonica, creating an environment that is not conducive to regeneration combined with an appropriated tillage system could effectively reduce its occurrence. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]