Efficacy of Various Herbicides for the Control of Perennial Plantago spp. and Effects on Alfalfa Damage and Yield

Abstract

Broadleaf (Plantago major L.) and buckhorn plantain (Plantago lanceolata L.) are perennial weeds that are notoriously difficult to control in alfalfa cropping systems. Sharpen® (saflufenacil) herbicide has been registered for broadleaf weed control in dormant alfalfa, although it has not been evaluated on plantain control. Field and greenhouse experiments were conducted to determine the efficacy of saflufenacil on plantain control with assessments of damage to alfalfa and effects on yield. In the greenhouse, applications of saflufenacil alone caused greater injury to both broadleaf and buckhorn plantain compared to the non-treated control (NTC). Additionally, applications of saflufenacil in combination with other herbicides (imazethapyr or imazamox) caused the greatest amount of injury to both broadleaf and buckhorn plantain compared to all other commercially available herbicide treatments. However, this injury was not enough to effectively control the weeds and prevent recovery and regrowth over time. In the field, alfalfa did not exhibit damage symptoms, or have reduced yield when treated with saflufenacil compared to the NTC. This research indicates that applications of saflufenacil provided temporary injury throughout the duration of the study to both broadleaf and buckhorn plantain with few negative effects to alfalfa in the field.