<p>Potato (<i>Solanum tuberosum</i> L.) does not have genotypes with resistance to root-knot (<i>Meloidogyne</i> species) nematodes. Thus, its sustainable production depends on intermittent inclusion of root-knot nematode-resistant crops in sequential cropping systems. The objective of this study was to investigate the efficacy of pre- and post-infectional nematode-resistant crops on managing population densities of <i>Meloidogyne</i> species in potato-based cropping sequences. Cropping sequences under field conditions comprised sweet stem sorghum (<i>Sorghum bicolor</i> L.) cv. ‘Ndendane-X1’, wild cucumber (<i>Cucumis africanus</i> L.F), potato cv. ‘Mondial G3’ and potato ‘Mondial G3’-velum (control), which were randomly assigned to 2&#xa0;m × 2&#xa0;m sub-plots in Sequence 1. The treatments were laid out in a randomised complete block design, replicated six times at two different locations. Sole potato cultivation was done in Sequence 2. In Sequences 3 and 4, crop arrangement was as in Sequences 1 and 2, respectively. At 56&#xa0;days after potato emergence, nematodes were sampled and extracted from roots and soil. Results from both locations showed an increase in final soil nematode population density in sorghum-potato (23% and 47%) and a decrease in <i>C. africanus</i>-potato (22% and 32%) cropping system. As such, post-infectional nematode resistance in the sequence <i>C. africanus</i>-potato was more effective in managing population densities of the test nematode species in the soil at both locations than the sorghum-potato sequence with pre-infectional resistance or the monoculture cropping.</p>