Emulsive water concentrate (EW) formulation of allelocompounds obtained from root exudates of sesame plants applied on tubers of purple nut sedge caused significant delay and inhibition in germination. EW formulation at 240 μg/g concentration of soil inhibited shoots and root biomass by 81.3 and 91.9%, respectively over control. Application of unformulated product on 15 days germinated tubers caused no significant effect on their growth and development at varying concentrations (0-240 μg/g soil) but showed adverse effect after some time. In pot experiment, isolated root exudates caused severe reduction in total shoot and root biomass of purple nut sedge. After two months, maximum reduction in total biomass and root biomass was observed by 68.0 and 90.0%, respectively at 240 μg/g of soil. Application of 240 μg/g of purified allelocompounds of root exudates caused 97% reduction in total number of newly formed tubers