ASSESSMENT OF PYCNOSTACHYS URTICIFOLIA SUSCEPTIBILITY TO THREE SPECIES OF MELOIDOGYNE

An exotic ornamental shrub, Pyncostachys urticifolia, growing in a residential planting in Orange County, Florida, was found to have root galling typical of root-knot nematodes (Meloidogyne spp.). Several gravid female nematodes were isolated from roots and identified as M. arenaria based on their esterase phenotype. Single egg mass cultures were produced and reinoculated onto P. urticofilia grown from seed in sterilized builder's sand in the greenhouse. The identification of subsequent egg masses was confirmed as Meloidogyne arenaria based on the esterase phenotype. Greenhouse experiments were then performed to assess susceptibility of P. urticifolia to two additional root-knot nematode species commonly found in Florida, M. incognita and M. javanica. Nematode galling and reproduction were evaluated for all three Meloidogyne spp. in replicated trials with Solanum lycopersicum (tomato cv. Rutger's) included as a susceptible control. Root galling was similar for P. urticifolia and S. lycopersicum for all three species of Meloidogyne tested, and the number of eggs produced per gram of root tissue was similar for S. lycopersicum and P. urticifolia for two of the three species tested, demonstrating that P. urticifolia is highly susceptible to M. arenaria, M. incognita, and M. javanica.