Effect of seed-applied fluopyram on Meloidogyne incognita infection and maturity in cotton and soybean

Fluopyram is being used to manage plant-parasitic nematodes in cotton (Gossypium hirsutum) and soybean (Glycine max), but the duration and depth of root protection from Meloidogyne incognita by seed-applied fluopyram is unknown. Both M. incognita susceptible cotton, Stoneville ‘ST 4848 GLT’, and soybean, Delta Grow ‘DG 4880 GLY’, cultivars were treated with fluopyram or abamectin and inoculated with second-stage juveniles in two greenhouse studies. Root penetration by M. incognita was suppressed from 7 to 21 d after planting by seed-applied fluopyram in soybean, while a similar trend in suppression was observed in cotton. Fewer nematodes per root system by fluopyram contributed to a reduction in root gall counts and nematode reproduction at 28 and 35 d after planting in both crops. Based on nematode developmental stages from 7 to 21 d after planting, fluopyram had no effect on nematode maturity. Root penetration by M. incognita was suppressed at 7 d after planting by fluopyram at a depth up to 5.0 cm in cotton and 2.5 cm in soybean. These results were similar to that of abamectin-treated seed. Seed-applied fluopyram and abamectin were most effective at suppressing nematode root entry rather than nematode maturity in cotton and soybean.