HALT Ambrosia Deliverables Complex research on methods to halt the Ambrosia invasion in Europe HALT Ambrosia Project ID: 07.0322/2010/586350/SUB/B2 Task ID: D Task Title: Best use of herbicides Deliverable ID: DD.2 Date: 01.12.2013 Deliverable Title: Efficacy sheets for bio-herbicides Responsible partner: JKI, AU Contact person: Dr. Ulrike Sölter (
[email protected]) Contributing partners: JKI, AU, Sl Kind of deliverable: X Based on project Desk top study results Introduction Pelargonic acid and acetic acid are bio-herbicides which are registered for non-cropping uses in some countries (Germany, Switzerland, USA). The phytotoxic effect of acetic acid was detected over 100 years ago (Fassbender and Grevillius, 1899). Pelargonic acid has been used for some years alone or in combination with glyphosate and glyphosinate (Arnold et al., 1993). Both acids are found in nature and are broken down rapidly. Pelargonic acid and acetic acid are contact herbicides which cause necrosis on direct contact with plant tissue while uncovered plant part like the root, will stay intact. Materials and Methods Pot experiments were conducted in Germany, Denmark and Slovenia from April until June 2012. Pelargonic acid and acetic acid were applied simultaneously at two growth stages of ambrosia (BBCH 14-16 and BBCH 22-25) in a spray cabinet (Germany and Denmark) or using a hand-held sprayer (Slovenia). Each bio- herbicide was applied at 5 dosages as a single application and as a split application with 50% at the first application and 50% 10 days later. The chosen bio-herbicides are registered for non-cropping uses in Germany: a) Acetic acid (Celaflor: 102g acetic acid/L) b) Pelargonic acid (Rasen MoosFrei: 187.7 g Pelargonic acid/L) The plants were harvested four weeks after the first application.