Propane Flaming as a New Approach to Control Mediterranean Invasive Weeds

In recent decades, anthropogenic activity and climate changes have reshaped global weed dispersal and establishment in new territories. This study aimed to evaluate the effectiveness of propane flaming approach in the control of perennial invasive and native Mediterranean broadleaf and grass weeds. The invasive weeds, <i>Cyperus rotundus</i>, <i>Sorghum halepense</i>, and <i>Ecballium elaterium</i>, were treated multiple times with a single propane dose (2.5 kg propane km^&#8722;1), using the broadcast technique. The local annual weeds, <i>Sinapis arvensis</i>, <i>Lavatera trimestris</i>, and <i>Avena sativa</i>, were treated once at five propane doses (0&#8211;2.5 kg propane km^&#8722;1), using the cross-row technique. Dose-response analysis was performed. Three applications provided effective control (up to &gt;90%) for all tested perennials, and affected seed and flower production in <i>Sorghum halepense</i> and <i>Ecballium elaterium</i>, respectively. However, the timing of the sequential application had a significant impact on the degree of control, in terms of dry weight reduction and seed production. Weed density had an impact on control efficacy but was only a significant determinant for <i>Ecballium elaterium</i>. Cross-row application was effective during early growth stages of broadleaf weeds (ED₅₀ &lt; 1.2 kg propane km^&#8722;1), but was less effective during later growth stages (ED₅₀ &gt; 2.6 kg propane km^&#8722;1). For grass weeds, both early and late application were ineffective (ED₅₀ &gt; 4.1 kg propane km^&#8722;1). More research is needed to optimize this weed control tactic for various cropping systems and weed species. Implementation of this novel approach into integrated weed management programs will increase the control efficacy of invasive weed under the projected climate changes and reduce the evolution of herbicide-resistant weeds.