Biodegradable and Safer Nematicides from Natural Sources

Abstract

Experiments were carried out to test nematicidal activity of extracts obtained from five abundant plants of Pakistan viz Atriplex stocksi , Azadiracta indicia ( Neem ), Datura, Fastuosa, Eichorina crapssipes , And Syzygium cumini, a brown marine alga Dictyota hauckiana and a marina animal Zoanthid in the control of Meliodogoyne javanica root-Knot nematode. In-vitro increasing in concentration of extract upon 1000 ppm , a decline in hatchablilty of the eggs and morality of j2 larvae of M.javabica root-knot nematode was observed with decreasing effects 100 and 10 pmm concentration . In-vivo studies, more than 50% reduction in root-knot development was observed on mungbean, egg plant, chilli ,tomato and okra used as test plants. An increase in the length of roots and shoot was also observed espically in the treatment where extracts were applied along with infestation with root-knot nematode. Soil drenching with water suspension of extract of D.fastuosa, significantly inhabited root-knot gall formation and also enhanced the growth of mungbean ,chilli, and okra with no egg plant and tomato. C. crasipes and D. haunckiana showed significant reduction of root-knot development of mungbean followed by A. indica , A. stocks , D. dastuosa , S. cumini and Zoanthid whereas in chilli and A.indica showed better results followed by A,. stocksi. Detailed chemical investigations on Zoanthid have resulted in the isolation of a number of nematicidal constituents.