MODELLING OF THE IN VITRO EFFECT OF CADUSAFOS ON MELOIDOGYNE INCOGNITA

Abstract

The nematicidal effect of cadusafos on eggs of Meloidogyne incognita was tested in two in vitro experiments. Final hatch was significantly reduced by four weeks incubation at concentrations =20 mg/ml. A 15 µg/ml diluition x 768 hour incubation periods was required to obtain a 90% mortality. The linear relationship between log time of exposure to different concentration and probit hatchability, fitted to the observed final hatch percentages, was: probit h=b[subC][subr]-mlog[sub1][sub0]t[subC]d[sup(][supC][suprû[supC][sup)]. Cr is a reference concentration and for Cr=25 µg/ml, b[subC][subr]=10.82, m=2.3 and d=0.9528. On a log scale, the above relationship is estimated by the general equation log[sub1][sub0]h=b'-m[subC][subr]td[sup(][supC][suprû[supC][sup)], with b'=2.1377, and m[subC][subr]=0.0013.