Nematicidal and Toxicity Effects of Eupatorium adenophorum Spreng against the Root-Knot Nematode Meloidogyne incognita in Soil Producing Cucumber

The root-knot nematode ( Meloidogyne incognita ) is a plant pathogen that causes significant economic damage to important food crops. The nematicidal and insecticidal effects of the essential oil and extract of the root and stem of different species of Eupatorium have been studied in several countries. We investigated the impact of root stems and leaves of the E. adenophorum on the second-stage juveniles (J2s) of M. incognita . Nematode mortality decreased by root-stem treatment and increasing temperature and time. Nematodes (J2) were more sensitive to root-stem treatment than leaf treatment at all tested conditions. For example, the half maximal effective concentration (EC 50 ) root-stems at 35 °C was estimated as 10.3 mg/g and in the 8th week as 7.8 mg/g, while the maximal effective concentration (EC max ) in leaf treatment is 20.3 and 10.1 mg/g, respectively. The E. adenophorum 40 mg/g concentration of root stems also produced the highest height of the cucumber stem and the highest cucumber fresh weight in the greenhouse. (E)-beta-farnesene, α-pinene and D-limonene, as the main identified components in fumigant plants, increased the mortality rate of J2s in root-stems treatment. We conclude that E. adenophorum dried root stems added to the soil in greenhouses have the potential as a bio-fumigant for M. incognita management.