Description

Abstract: Single populations of Meloidogyne arenaria races I (MA I) and 2 (MA2) and M. hapla (MH), and mixed populations of MAl + MA2 and MAl + MH with four inoculum levels of eggs were tested on peanut cv. ‘Florigiant’ and M. incognita-resistant tobacco cv. ‘McNair 373’ in a greenhouse experiment. Root infection, female development, and reproduction of MA2 on peanut and MAlon resistant tobacco were limited at 2 and 6 weeks. MA I, MH, and MA I + MH on peanut had similar root infection (total parasitic forms per root unit) at both 2 and 6 weeks, and similar female development and reproduction potentials at 6 weeks. MA2 tended to depress root infection, female development, and reproduction of MA I on peanut. MH had little effect on MA I on this crop. On tobacco, MA2 pO,pulation had greater incidence of root infection than did MH at 2 weeks. The two nematode species had similar development in roots at 6 weeks. All of these processes were restricted when either MA2 or MH was present together with MA I. As initial inoculum level of parasitically fit populations increased, relative infection ratio on both peanut and tobacco, and reproduction factor on peanut decreased. Populations that had high infection incidence and reproduction rates induced greater root ,galling than did other populations. Root galling was suppressed in the presence of antagonistic response between nematode populations.