Department of Agronomy, Annamalai University, Annamalainagar-608 002 (Tamil Nadu), India.
A study was conducted at Annamalai University, India during 2002 on the efficacy of different adjuvants in enhancing the foliar activity of botanical herbicide, Coleus amboinicus/aromaticus on water hyacinth control, in an integrated bio-control approach, with an ultimate aim of reducing the dose involved. Three different adjuvants used were APSA-80, Dhanuvit and Maxiwet. Addition of adjuvants was effective in enhancing the activity of botanical herbicide. The integrated bio-control using insects+aqueous extract of coleus leaf powder @ 20% +0.2% APSA-80 and insects+aqueous extract of coleus leaf powder @ 20% + 0.2% Dhanuvit recorded the cent per cent reduction in fresh weight and chlorophyll content of water hyacinth on 40 and 30 days after spraying. No insect mortality rate was observed in any of the treatments.
