Toxicity of certain weed extracts and their combinations with aphicides against

Aphis gossypii Glov

[71]

Ali¹, I.H.H. and Rodina A. Hassan²

ABSTRACT

The toxicity of five weed extracts either alone or mixed with aphicides were studied against the adult stage of Aphis gossypii. Data showed that the petroleum ether extract of Pimpernel and ethanol extract of Chickweed were the most effective at LC₅₀ and LC₉₀ levels while Purslane extract was the least toxic. The petroleum ether and ethanol extracts of Blackmustard when mixed with aphicides (Cyanox and KZ oil) at the LC₂₅ level exhibited a very promising synergistic activity and could be used in combinations for controlling the adult stage of Aphis gossypii. Only ethanol extracts  of  Cogongrass  mixed  with  Cyanox and Pimpernel mixed with KZ oil gave synergistic effects but with lower degrees. Also, Chickweed/KZ oil mixture produced synergism in both tested solvents whereas Chickweed/Cyanox mixture gave antagonistic activity by using the same solvents.