In the study, we selected 12 plant species to evaluate the influence of one, two and four plant species combinations on tomato growth and population suppression of the rootknot nematode, Meloidogyne incognita, and the whitefly, Trialeurodes vaporariorum in a pot trial. The addition of onecompanion plant species resulted in a lower number of M. incognita eggs in Lolium perenne and Mentha haplocalyx pots compared with control pots (without companion plants). Additionally, there was a decline in total number of the nematodes in the other companion plant treatments as well. Furthermore, the number of the T. vaporariorum was significantly lower in the presence of companion plant treatments than in control pots. In general, plant identities have a greater potential to control M. incognita than plant diversity.