Shocking results: interspecific variation in response to low-energy electrocution for weed control at various phenological stages.

Abstract

BACKGROUND Low-energy electrocution and robotics are emerging technologies in weed management. Optimizing robotic weed-electrocution platforms require biological insights to improve energy efficiency and operational effectiveness. Although previous studies have shown varying sensitivity across species and growth stages, precise energy thresholds for control remain unclear. This study aimed to quantify energy requirements for effective weed control across species and developmental stages using dose response methodology. RESULTS Significant interspecific variation was observed. The dicots species Amaranthus retroflexus and Solanum nigrum were more sensitive to electrocution than the monocots Sorghum halepense and Setaria adhaerens, with S. halepense exhibiting the highest resistance. At the four true-leaf stage, ED90 estimated values ranged from 0.009 W h (A. retroflexus) to 0.099 W h (S. halepense), demonstrating high variability in energy requirements. Sensitivity declined at advanced growth stages, with ED90 values increasing by up to fourfold, confirming the hypothesis that younger plants are easier to control. Rhizome-originated S. halepense plants were more resistant than seed-originated ones at early stages, but this difference diminished at advanced growth stages. Survival varied significantly between experimental runs, highlighting potential variability in plant physiology or environmental factors. Biomass ratio responses were more consistent and useful for optimizing doses. CONCLUSION Low-energy electrocution is a promising weed control method, especially when applied at early growth stages. Efficacy is influenced by species, growth stage and propagule type. Establishing precise energy requirements for control can enhance the efficiency and performance of this technology, optimizing its application as part of integrated weed management. © 2025 Society of Chemical Industry.