Relative damage functions and reproductive potentials of Meloidogyne arenaria and M. hapla on peanut

The reproductive potential and damage functions for Meloidogyne hapla and M. arenaria race 1 on Virginia-type peanuts (Arachis hypogaea cv. Florigiant) were determined over 2 years in microplot experiments in North Carolina. Peanut yield suppression and damage to pods as a result of galling were greatest in response to M. arenaria (P = 0.01). Damage functions for the two species were adequately described by the quadratic models: yield (g/plot) = 398 - 17.1 (log10[Pi + 1]) - 17.0(log10[Pi + 1])2; (R2 = 0.83, P = 0.0001) for M. arenaria; and yield = 388 - 10.2(log10[Pi + 1]) - 7.5(log10[Pi + 1])2,(R2 = 0.30, P = 0.0001) for M. hapla. Both species caused galling on pods, but this was more severe in response to M. arenaria. Reproduction of M. arenaria race 1 was greater than M. hapla on peanut, which accounts in part for the more severe pod galling. Peanut was an excellent host for both M. arenaria race 1 and for M. hapla, but reproduction by M. hapla was more variable.