Control of water hyacinth (eichorniacrassipes) using weevil

John D and MerlineSheela A

This study is related to the assessment of bio-control potential of Neochetina spp. Weevils on the weed Eichhorniacrassipes. The outcome of the study indicates treatment with two weevils per plant are most effective in controlling the aquatic weed, the reduction phenotype characters of Eichhormiacrassipes namely, plant density, biomass (31.3%), petiole length (28.42%), Plant height (28.42%) root length (10.54%) and leaf length (9.79%) leaf width (7.46%) in the period of 90 days. Numerous feeding scars observed in the first 15 days, and production of ramets or re-sprouts were greatly reduced by the introduction of Neochetinaspp weevil. The results are encouraging and it is calculated that 3000 weevils are required for effective control of water hyacinth in the water spread of one hectare coverage. Also the water quality analysis was performed to find the impact of decay of Eichhormiacrassipes on the effect of thephysical factors such as wind velocity, temperature, light and water flows does not affect the bio-control potential of the bio-control agents Neochetina spp. Weevils are capable of sustainable to the tropical climate of Tamilnadu state.The biological treatment is environmentally safe, sustainable and self perpetuating.

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