2024 Volume 69 Issue 3 Pages 104-108
Lawn burweed (Soliva sessilis Ruiz & Pav.), an annual weed native to South America, has sharp achene spines that prevent the use of lawns. It is difficult to control lawn burweed by mowing because of its creeping growth form. We conducted field experiments to assess the effects of foliar applications of hot water as a lawn burweed control. In mid-April, a pressure washer was used to apply hot water (98°C) to plants in a park in Tokyo, Japan. Individual plants were spot treated with 304–1,824 mL of hot water per plant (treatment time 2–12 sec); all died by 28 days after the treatment. Surface treatment of a 1 m × 1 m-plant community comprising 10–20% lawn burweed with 760, 1,520, or 2,280 mL/m2 of hot water for 5, 10, or 15 sec, reduced the lawn burweed coverage to less than 8%. However, the 760-mL/m2 treatment sometimes resulted in uneven spraying of tall plant communities, so a minimum of 1,520–2,280 mL/m2 should be used.
