Integrated approach for controlling water hyacinth

摘要

The experiment was conducted at Annamalai University, Tamilnadu, India to study the possibility of interaction between botanical herbicide Coleus amboinicus/ aromaticus with insect agents Neochetina eichhorniae/ bruchi. Single control options was found inefficient for managing the worlds worst aquatic weed water hyacinth. The integrated approach of releasing the insect agents Neochetina spp. onto the weed and spraying the aqueous extract of leaf powder of Coleus spp. showed synergistic interaction inreducing the fresh weight and chlorophyll content of water hyacinth. Among the three inoculation loads of insect agents, viz. three, two and one insects/plant, three/plant followed by spraying the extract of Coleus spp. leaf powder at 25% proved significantly superior in reducing the fresh weight and chlorophyll content to on 60 and 50 days after releasing the insects, respectively.Among the different interludes or time lag compared for evolving a standardized method of integrating foliar spray of leaf powder extract, viz. 10, 20 and 30 days, 10 days performed superior by achieving fresh weight and chlorophyll content reduction andleast weed nutrient content of water hyacinth. No insect mortality was observed in any of the treatments.