ED50 Values in Bioassay Techniques

Cucumber (cv. Guntur local) indicated high sensitivity to pendimethalin, f1uchloralin, trifluralin and alachlor, but not responded to f1uazifop-butyl. For pendimenthalin, maize shoot weight inhibition bioassay is suitable with lower ED₅₀ value. For trifluralin, finger millet root length/weight bioassays indicated narrowest ED₅₀ values with wide range of response. Cucumber shoot length bioassay for f1uchloralin and finger millet shoot weight bioassay or shoot length of cucumber for alachlor were found most suitable. Maize shoot length or weight inhibitions indicated sens'itivity to fluasifop-butyl herbicides. Narrower ED₅₀ values with wide range of response appear to be best parameters to decide the suitable bioassay technique.