Plant eradication using by inflicting upon a plant root (R) unnatural hot wound mechanical and thermal trauma delivered from a hot stab knife (V) which produces a stab gash (K) sufficiently deep to traverse plant cortex (C) and penetrate to plant xylem (X), simultaneous with or followed by heating the damaged area to a temperature of higher than 70 C, preferably 200 C for a sufficient time to cause cellular damage to the plant root. The root and hot stab knife may be shrouded to increase the temperature adjacent the stab gash. Preferably, the stab knife is formed to be sufficiently acuate and flat so as to allow a surface/volume ratio for the stab knife to be at least twice that of a cone of similar size and extent. Unhealable damage results, believed to caused by role conversion of organisms in the rhizosphere from sybiosis to antagonism.