Root-knot nematodes (Meloidogyne spp.) are serious disease causing agents and attack nearly all types of plants. In
this study 32 seaweeds were evaluated to determine nematicidal activity against Meloidogyne javanica (egg
hatching and larval mortality tests) in vitro. Results revealed that seaweed biochemical potential in two different
solvents viz., water and methanol @ ratios 2.5, 5 and 10%. It is observed that Sargasssum tenerrimum, Padina
tetrastromatica and Melanothamnus afaqhusainii showed maximum egg hatching (96%) and larval mortality (99%)
and (100%), respectively in water and methanol extract @ 10% concentration after 72 hours exposure time.
Similarities between Ward’s cluster analysis of hatching egg and larval mortality in water and methanol extract of
different seaweeds showed significant difference. Methanol extract was more effective as compared to water extract.
In conclusion, use of seaweeds is positive sign against harmful microorganisms which are responsible for
considerable losses in agriculture yield.