Evaluation and Structure Activity Relationships of 0-aryl 0-2-chloroethyl 0-methyl phosphates for Nematicidal activity against Root knot Nematode

A series of 20 new 0-aryl 0-2-chloroethyl 0-methyl phosphates has been assayed in vitro against the root knot nematode Meloidogyne incognita. Quantitative Structure-activity relationship studies using physico-chemical substituent parameters for electronic, hydrophobic and steric properties revealed that nematicidal activity of phosphate compounds against M. incognita was mainly affected by electron withdrawing nature of benzene ring substituents. Steric parameters MR₍₀₎ and L_(p) also affected the nematicidal activity to some extent. Six active compounds have been further evaluated in glasshouse test using P-80 variety of soybean (Glycine max), 0–2, 4-6trichlorophenyl 0-2-chloroethyl 0-methyl phosphate was most active compound which significantly reduced the number of root galls.