Efficacy of herbicides for the control of Ambrosia grayi
Ambrosia grayi (Asteraceae: EPPO Alert List) is native to North America (Mexico and the USA) and is a invasive alien species in Israel where it is under eradication. Various herbicides were tested to develop practical solutions for controlling A. grayi. Testing was conducted on two growth phases, young plants with 4-6 leaves and mature plants with 12-15 leaves. The treatment included the active substances Fluroxypyr + Saflufenacil + surfactant; Fluroxypyr + Glufosinate; Fluroxypyr + Glyphosate; Glufosinate + Glyphosate + Saflufenacil + surfactant. In general, all herbicides showed a high level of efficacy for the control of A. grayi. When the herbicides containing Glufosinate were applied to young plants, they caused severe damage, resulting in no survival or no regeneration at this growth stage. However, mature plants did show some development of the bud. Survival rates (21 days post-herbicide application) and regeneration capacity of rhizomes (42 days post-herbicide application) were assessed and survival was the lowest for young plants. Mature plants showed a survival rate of 33 to 56 %. There was no rhizome regrowth for both young and mature plants, except for mature plants (11 %) when treated with Fluroxypyr + Saflufenacil+ surfactant.
Sources
Neta D, Abu-Nassar J, Cafri D, Ezra N, David I, Shtein I, Goldway M, Eizenberg H, Matzrafi M (2024) Ambrosia grayi as a new alien casual species in Israel: plant biology and chemical management. Pest Management Science, DOI 10.1002/ps.8048