Movement of Fluopyram in Sandy Soil to Affect Meloidogyne incognita Motility

Fluopyram is nematicidal to Meloidogyne incognita. It has limited xylem movement, thus direct contact is important for nematode suppression; however, the effective movement of fluopyram in sandy soil is unknown. The objective of this study was to determine the movement of fluopyram from treated seed and a water dilution in sandy soil. Treatments consisted of 0.15 mg abamectin, 0.25 mg fluopyram, and 0.75 mg thiodicarb + imidacloprid treated cotton seed, while water dilutions of 25 µg abamectin and 25 µg fluopyram were used in the second experiment. Each treatment was placed on the surface of the soil column and flushed with 500 µl of water. In a third experiment, the total water volume was divided in smaller doses and distributed over 30 days. The soil was removed after 24 h from three, 5-cm long segments and mixed with an equal volume of water. A portion of the supernatant was placed into a well, which contained 30-40 J2. In the first experiment, a higher percentage of immotile J2 were observed from fluopyram collected in the 0-5 and 5-10 cm segments than abamectin. No nematode immotility was observed with thiodicarb or water control. In the second experiment, a higher percentage of immotile J2 were observed in the 5-10 cm segment from the water dilution of abamectin and fluopyram compared to the treated seed. No nematode immotility was observed past the 10-cm depth for either nematicide. In the third experiment, a higher percentage of immotile J2 were observed from fluopyram in the 10-15 cm segment than abamectin. The effective movement of fluopyram in sandy soil within 24 h was limited to the upper 10-cm of soil, which was similar to that of abamectin, but after 30 d more fluopyram was observed past 10-cm of soil than that of abamectin.