Nematicidal activity of fluensulfone against some migratory nematodes under laboratory conditions

The fluoroalkenyl fluensulfone, known to have strong nematicidal activity against Meloidogyne spp. (root-knot nematodes), was evaluated in vitro and in soil against the migratory nematodes Bursaphelenchus xylophilus, Aphelenchoides besseyi, Aphelenchoides fragariae, Ditylenchus dipsaci, Pratylenchus penetrans, Pratylenchus thornei and Xiphinema index.

B. xylophilus and D. dipsaci were not immobilised by 48 h in vitro exposure to up to 16 mg L(-1) of fluensulfone. A. besseyi and A. fragariae were affected by 8 mg L(-1) , the highest concentration used for these nematodes. More than 60% of P. penetrans and P. thornei were immobilised by 4 mg L(-1) of fluensulfone; however, exposure of P. penetrans to the compound prior to inoculation did not affect their root penetration ability. The immobilisation rate of X. index was increased by 48 h exposure to even 1.0 mg L(-1) of fluensulfone. Incorporation of over 2 mg L(-1) of fluensulfone into the soil reduced populations of P. penetrans and P. thornei before and after planting lettuce and chickpea respectively. The efficacy of fluensulfone against the tested nematodes was the same or higher than that of fenamiphos in most cases.

A. besseyi, A. fragariae, B. xylophilus and D. dipsaci were tolerant to fluensulfone and fenamiphos. P. penetrans, P. thornei and X. index were affected by fluensulfone, but nematicidal activity was much lower than that reported for root-knot nematodes.