Nyczepir, A. P. 2009. Dynamics of concomitant populations of Pratylenchus vulnus and Meloidogyne incognita on peach. Nematropica 39:273-279. The effect of the interaction between Meloidogyne incognita and Pratylenchus vulnus on nematode reproduction and vegetative growth of Lovell peach was studied in field microplots. Pratylenchus vulnus suppressed the population density of M. incognita second-stage juveniles, whereas the presence of M. incognita did not affect the population density of P. vulnus in soil. Above-ground tree growth, as measured by trunk diameter 12 and 24 months following inoculation, was reduced in the presence of M. incognita. Differences in root growth as related to nematode treatment were detected 26 months after inoculation. Root growth was reduced in the presence of the two nematode species together than P. vulnus alone, but not when compared to M. incognita alone. There was a greater negative impact on vegetative growth of peach seedlings growing in M. incognita-infested soil than in P. vulnus-infested soil.