Lantana kills water hyacinth at 3 % concentration in pot
experiments (Saxena 2000). Toxicity increased with the
concentration of Lantana leachates from 1-3 %. Though initial
results were obtained good and coincided with that of lab
experiments in the present study. Toxicity disappeared after 20
days which may be possible by decomposition of the toxic
allelochemicals after few days. Water hyacinth’ growth decreased
tremendously at 1.2 % concentration initially up to 20 days but
regained after 20 days in the field conditions. It is pertinent to
mention here that Toxicity of Lantana leachate gradually
decreased with time and ultimately lost within 15 days (Gupta,
1998). The loss of toxicity of Lantana leachate in field after 20
days is well explained because of the deterioratation of
allelochemicals present in the leachate. To overcome, higher
concentration 3-5% may be tried in the field for effective results
with Lantana. Additionally, leachate can be added fortnightly to
get better results