Root-knot nematode (Meloidogyne incognita) (RK) causes yield losses in cotton. Small-plot variety trials were conducted in the southern High Plains of Texas to evaluate RK density (2nd-stage juveniles + eggs/500 cm3 soil) and cotton (Gossypium hirsutum) lint yield across commercially identified RK-resistant varieties. These varieties were compared to susceptible varieties (SUS) in nine trials over two years. Only a subset of resistant and SUS varieties was included in each location. Varieties that had consistently lower (p = 0.05) transformed RK densities (LRK) compared to SUS were DP 2143NR B3XF (6 of 9 trials), DP 2141NR B3XF (3 of 6 trials), DP 2436NR B3TXF (2 of 5 trials), PHY 205 W3FE (2 of 4 trials), PHY 332 W3FE (3 of 4 trials), PHY 411 W3FE (2 of 3 trials), PHY 415 W3FE (2 of 3 trials), PHY 443 W3FE (3 of 4 trials), PHY 475 W3FE (3 of 4 trials), and PHY 480 W3FE (2 of 2 trials). In contrast, FM 765AX, FM 823AXTP, FM 868AXTP, and ST 6000AXTP did not exhibit reduced LRK densities relative to SUS in any trial. Varieties that had consistently higher (p = 0.05) yield than SUS included FM 765AX (2 of 3 trials), PHY 475 W3FE (2 of 4 trials), and PHY 480 W3FE (1 of 2 trials). Cotton producers should consider both the level of resistance of a variety as well as yielding ability in a region when making variety choices for planting cotton in RK fields.
