Kontrolle von Rumex spp. mit Citronella-Öl im Organischen Landbau

Citronella is an oil, extracted from lemon grass species (Cymbopogon sp) and has been identified as a potential burn-down bioherbicide. In greenhouse pot experiments two fractions of dock roots, Rumex obtusifolius and Rumex crispus (light root fraction, LW: 5-12 g root weight and heavy root fraction, HW: 15-30 g weight) were planted. 116 days after planting the mass of the untreated control gave an increase of 600% (LW) and 300% (HW) root mass, respectively. Citronella oil hindered the accumulation of assimilates in the roots showing a slight decrease of the initial root mass. Efficacy of citronella oil was higher as with cutting the leaves. Citronella oil also showed its efficacy to decrease the leaf area of dock plants after application of lower concentrations (12.5%, 25% and 50% of the recommended concentration), rather than their counterparts acetic acid and pelargonic acid