Yellow Nutsedge (Cyperus esculentus) Management with Electrical Weed Control

Abstract

Yellow nutsedge (Cyperus esculentus L.) is an important perennial weed in horticultural crops that is difficult to manage due to its aggressive growth, prolific spread, and extensive tuber network, as well as its tolerance to a wide range of moisture and soil conditions. These characteristics make control especially challenging in organic farming systems. Electrical weed control (EWC) is an emerging nonchemical strategy that delivers electrical energy to plant tissues, disrupting cellular structures. This study evaluated EWC for C. esculentus control using tractor-powered systems in 2023 and 2024: an alternating-current unit (EH30 “Thor”; Zasso™ Group AG, Zug, Switzerland) and a direct-current unit (XPower XPS; Zasso™ Group). Treatments included EWC applied at different energy levels (24 to 518 kJ·m-2) by varying operation speeds (0.5 to 3 km·h-1), applied singly or sequentially, as well as mowing and combined mowing followed by EWC. In the 2023 Corvallis study (alternating current system), mowing and slow-speed EWC at 0.5 km·h-1(144 kJ·m-2) controlled C. esculentus shoots (88%) at 14 days after initial treatment (DAIT), but regrowth occurred over time. Sustained control was achieved with mowing followed by EWC (81%) and sequential EWC applications (80%) by 56 DAIT. Three passes at 3 km·h-1(24 kJ·m-2per application) provided 75% control at 80 DAIT. In greenhouse assays, field-treated tubers were evaluated for viability. Mowing followed by EWC reduced shoot emergence (38%) and shoot biomass by 42% compared with nontreated control. The 2024 study (direct current system) confirmed the advantage of sequential EWC: three passes at 3 km·h-1(86 kJ·m-2) achieved 93% control at 80 DAIT. Sequential and combined treatments (EWC two passes at 2 km·h-1, EWC followed by mowing) reduced tuber density (52% to 57%) and weight (46% to 56%) compared with the nontreated control. EWC demonstrated strong potential for shoot suppression of C. esculentus, particularly when applied sequentially or combined with mowing. Importantly, treatment order was critical: mowing followed by EWC providing greater weed control (81%) compared with the reverse sequence (EWC followed by mowing, 61%).