Sensitivity of Ambrosia artemisiifolia to glufosinate and glyphosate at various developmental stages

Abstract

Gauvrit C & Chauvel B (2010). Sensitivity of Ambrosia artemisiifolia to glufosinate and glyphosate at various developmental stages. Weed Research50, 503–510.SummaryGlufosinate and glyphosate at 375 g a.i. ha−1 and 540 g a.e. ha−1, respectively, were assessed for control of Ambrosia artemisiifolia under non‐crop conditions at four different developmental stages (vegetative, BBCH 14; bud appearance, BBCH 53–55; onset of pollen production, BBCH 61; mid female flowering, BBCH 73–77). Both herbicides displayed high efficacies at all development stages. However, after treatments at BBCH 14, new emergence or re‐growth of A. artemisiifolia led to the presence of plants that produced pollen and seeds. Treatments at BBCH 53–55 gave more than 99.9% reduced pollen production. Seed production was more than 99.9% reduced by glyphosate and 92.0–99.8% by glufosinate. Treatments at BBCH 61 suppressed viable seed production by more than 99.8%. When treatments were made at BBCH 73–77, seed production by A. artemisiifolia was not significantly affected, but seed viability was decreased by 10–85%. Although significantly reduced, the number of viable seeds was still 283–652 and 827–3893 m−2 in the plots treated by glufosinate and glyphosate respectively. It is concluded that on non‐crop areas, herbicide treatment of A. artemisiifolia at bud appearance (BBCH 53–55) with glufosinate or glyphosate gave the most effective control of both pollen and seed production.