Nematostatic Activity of Oxamyl and N,N-Dimethyl-1-cyanoformamide (DMCF) on Meloidogyne incognita Juveniles.
The nematostatic activity of oxamyl, methyl-N',N'-dimethy]-N-hydroxy-l-thiooxamimidate (oxamyl-oxime) and N,N-dimethyl-l-cyanoformamide (DMCF) was studied by immersing 10 Meloidogyne incognita second-stage juveniles into aqueous solutions of various concentrations of each chemical. At concentrations of 500 to 8,000 mug/ml, oxamyl quickly immobilized immersed juveniles. In all other concentrations studied (down to 4 mug/ml), oxamyl stopped or reduced movement of juveniles within 24 hours. DMCF also quickly immobilized juveniles at concentrations of 4,000 and 8,000 mug/ml and reduced movement at 2,000 mug/ml. Lower concentrations had no observed effect on movement. In solutions of the oxime from 2,000 to 8,000 mug/ml, some reduction of movement was observed, but most juveniles maintained some motion over a period of 24 hours. Juveniles were transferred to water from 4,000 mug/ml solutions of oxamyl and DMCF after various intervals of time in order to determine the effect of duration of exposure to the chemicals on the ability of the immobilized juveniles to recover normal motion. Some recovery was observed even after 24 hours of exposure to DMCF, but none after exposure to oxamyl for longer than 40 minutes.
McGarvey
B D
BD
Potter
J W
JW
Chiba
M
M