The herbicidal potential of Pelargonic Acid to control Cirsium arvense (L.) Scop. in relation to the timing of application and the application volume

Pelargonic Acid (PA) is a naturally occurring fatty acid that is used as a bio-based herbicide to control both annual and perennial weeds. In this particular study, we investigated the effects of influencing factors on the efficacy of PA on Cirsium arvense (L.) Scop. under semi-field and greenhouse conditions. For this purpose, we examined the effects of different timings, application volumes, and adjuvants of PA to control C. arvense. Two application volumes (10.9 kg PA at 200 L and 400 L water/ha), and five plant growth stages were tested in a semi-field experiment. In a greenhouse experiment, Paraffin oil, as an adjuvant, was added to both PA application volumes to evaluate the possible increase in PA herbicidal efficacy. Our results showed that 10.9 kg PA in the volume of 400 L water/ha improved the PA efficacy. Paraffin oil, as an adjuvant, can enhance PA efficacy. The most effective times to control using PA were early-elongation and the seven-to-ten leaf stages for C. arvense. We conclude that 10.9 kg PA with an application volume of 400 L/ha and added adjuvant is a mixture with a herbicidal potential when applied at an earlier stage of C. arvense.