Root-knot and reniform nematode are widespread cotton nematodes but are rarely found together in the same fields. There doesn’t appear to be a strong interaction between populations of these two nematodes in 397 fields where both nematodes have been found in Louisiana. As the population level of one nematode increased, there was not a corresponding decrease in the other nematode. Although both root-knot and reniform nematode have extensive host ranges, there are discrepancies in host specificity that makes it possible to favor development of one over the other. Peanut stands out as the one of the only rotational crops that appears to be immune to both nematodes. Reniform nematode shows considerable variation in reproduction on crops such as cotton. Management options for this nematode may change in the future as this variability is better characterized.